Water-Energy-Nexus in the Ecological Transition

Any investment in the water and energy sectors has to deal not only with technological issues but also with financial aspects—related to the ability of the project to generate adequate profitability in the relevant market—and to forecast the environmental, social, and cultural effects. In this perspective, the literature provides methodological approaches and evaluation tools. The main references are the cost–benefit analysis (CBA) and multi-criteria techniques. The CBA makes it possible to make judgments about the cost effectiveness of the interventions. The results are expressed in quantitative terms, using the well-known indicators net present value, internal rate of return, benefit–cost ratio, and payback period. Studies allow translating a series of extra-financial effects of investment into monetary terms and considering its risk components and to implement sophisticated models to discount the corresponding cash flows. Instead, the multi-criteria techniques evaluate the multiple effects of an intervention through different value scales, both quantitative and qualitative. Thus, it is possible to obtain a ‘profile’ of the project effects, looking at its ability in increasing the community well-being. The paper is intended to provide an overview of decision support models. It also aimed to compare the different approaches, propose new evaluation schemes according to the specificities of the water and energy sectors, and represent research perspectives. This was achieved taking into account the essential community and international guidelines on the water resources and energy transition management.

This research dealt with the urban underutilization of a specific part of the twentieth-century architectural heritage in Italy, i.e., the War Wounded Houses. These buildings, widespread throughout the nation, are mostly abandoned or in a state of neglect. They are also technologically obsolete, and their energy refurbishment seems to be highly unavoidable to promote a new use for these premises. This paper analyzed and suggested a strategic approach to increase sustainability in the building sector in terms of landscape (re-)use and energy efficiency interventions. Acting on the twentieth-century Italian cultural heritage is an opportunity to revitalize urban settings through the cooperation between the theories of architectural conservation, energy retrofit procedures, and financial analyses. The proposed approach, applied to one pilot case study, involves a life cycle costing and a cost-optimal method, used to evaluate and compare different possible energy retrofit scenarios, balancing initial and running costs until the optimal level of intervention is identified. The procedure allows finding the design solution that combines their best energy efficiency targets with costs reduction goals over an extended analysis period. The model also aims at being a repeatable approach for similar cases, where buildings, not appropriately used in their urban context, can be a strategic element in renewal and sustainability processes.

The rapid economic and demographic growth of recent decades, together with the rising living standards and the unplanned urbanization process, have caused a disproportionate use of water and energy resources. This requires methodologies to support the decision-making processes capable of establishing sustainable actions and strategies. Therefore, in the Cost–Benefit Analysis (CBA) of investment projects, it is of increasing interest to also consider the extra-financial effects that are generated. For such effects, conventional discount procedures are often inadequate, especially when intergenerational environmental effects need to be assessed. This paper proposed a model that differently discounts the economic effects and environmental impacts that projects in the water and energy sectors determine. The model outlines a declining structure for both of the economic discount rate and the environmental discount rate. The main novelty of the model lies in the introduction of environmental quality into the logical-mathematical estimation scheme. Environmental quality is expressed according to the indicators that contribute to the Environmental Performance Index (EPI). The use of dual and declining discounting procedures makes it possible to give greater weight to environmental externalities, orienting guiding the decision-maker towards more sustainable investment choices.

Energy Efficiency Certificates (TEE, also called white certificates) are negotiable securities that certify the achievement of energy savings in energy end-use through measures and projects to improve energy efficiency. Electricity and natural gas distributors may achieve their energy efficiency improvement targets both by implementing energy efficiency projects (and gaining TEE) and by purchasing TEE from other parties. Despite all these incentives and goals for energy utilities, investments in 2020 are decreasing. The causes of this regression are the extreme slowness of certifying procedures and the impossibility of accumulating energy efficiency investments with other public state aids. To ensure the industrial sector to achieve the objectives established by the PNIEC in terms of decreasing consumption, a global reform that is able to relaunch the mechanism would therefore be important, mostly in the post-COVID-19 crisis. The article shows the convenience for a medium-sized gas distributor, but could be applicable for energy distributors, of investing in direct projects of energy efficiency or financing these projects to achieve the goals imposed by the PAEE (Energy Efficiency Action Plan).

The use of pesticides and antibiotics, as well as land consumption, are among the well-known limitations of traditional farm technologies. To date, several solutions have been developed, including aquaponic systems. These systems combine aquaculture, a process for the breeding of fish species, with hydroponics, a process for the cultivation of soilless plant species. Aquaculture would allow providing high-quality products, through the utilization of healthy nutrients to plants and a careful and rigorous control of the food to be supplied to fish species. BIO-products have a higher market value than products obtained by a normal cultivation or breeding method. Therefore, aquaponics would enable not only the reduction of the previously set limits but also the provision of significant economic advantages, increasing the market value of the obtained food resources. Finally, aquaponics can be established as a strong and concrete way on a local market (at 0 km), which goes directly from the producer to the consumer. The aim of this research study was to make a technical–economic analysis of novel aquaponic system generation for sustainable development, made by the Sanitary Environmental Engineering Division (SEED) in collaboration with the Project Evaluation Laboratory (PEL). Both research groups are from the University of Salerno and the Center for Membranes and Advanced Water Technology (CMAT), Abu Dhabi. An economic feasibility study highlights how the aquaponic system can be a launching pad for all entrepreneurs who intend to invest in this sector. Sufficiently, high cash flows guarantee good profitability in the short term, even for small investments.

The significant infrastructural gap that Italy suffers from compared to European competitors is highlighted significantly in the water field. The Blue Book 2020 emphasizes the water losses level, reaching 45%, and the age of water mains that even rises up to more than 50 years. The questions to be addressed are, therefore, the huge investments allocated for the modernization of the plant assets by rationally planning the resources to be used for this purpose, on the one hand, and how to set an effective exploitation of the European aids decided in the last European Council, on the other. The planning can take place with the support of expeditious tools for the preventive estimate of investment costs, allowing an easier and quicker evaluation of the convenience of the expenses to be planned. The rapid estimation tools include multivariate models which, based on regressive functions trained on real cases, can contribute to interpret the phenomenon of price formation and identify useful predictors in the preventive phase. Among the suggested models in the bibliography is the one proposed by the University of Salerno in 2003 in the research project about the selection and cost control in urban and territorial redevelopment, financed with funds from the Ministry of Education, University and Research. This unknown work, published only in Italy, applies the model to multiple case studies other than those assumed for its development and highlights its strengths and weaknesses, proposing a change to increase the effectiveness of the contingencies imposed by the legislation on the integrated water service.

Brazil has nearly a fifth of the world’s water reserves; however, water is not evenly distributed. The Northern region holds more than 80% of all water amounts; also, the country has semi-arid areas, like the Northeastern region, which suffers from repeated multiannual droughts. Energy, land, and water are key elements to society’s well-being and are intricately linked to all other sectors within an economy. The decision to use a specific technology for energy production is often based on the lowest cost, without considering important aspects such as water cost and availability, the non-energy water demands, and the aquatic ecosystems. The importance of strengthening Brazilian water governance is one of the main suggestions for a permanent scarcity crisis. Thus, water cost mechanisms were evaluated as governance instruments to face water crises in semi-arid Brazilian rivers. It is shown how a water value for the thermal power sector can vary in scarcity period to avoid its dispute to other users. For the São Francisco basin (case study), the dispute for water essentially takes place between power generation and crop production. Results show the different applications of the water valuation method and in which situations it is most financially indicated to use water to produce electricity or food.

In Italy, over the past few years, the fragmentation of the management system of water services, especially in the south of the country, has required big efforts on the National Authority (ARERA). Efforts aimed to achieve the homogenization of the methods and procedures adopted by the public or private regulated companies in the management of the integrated water service. Specific attention was paid to the reorganization of the tariff classes to bring together very different approaches within a single model subject to precise rules. In particular, through the TICSI (Integrated Text for the tariff classes of water service, approved by ARERA with resolution n. 665/2017/R/Idr), it was decided that the maximum number of tariff classes be equal to five; the ratio between the last class tariff and the first class tariff must be less than six; another constraint to be respected is about the revenue which must be the same with respect to the two-year period preceding the regulatory review. It is therefore a typical problem of optimizing an economic function. In fact, guaranteeing an unchanged revenue, the tariff classes must be defined by providing a facilitated class and a base class, where the facilitated has the social function of protecting the less privileged sections of the population and building, then, the other upper classes in relation to the manager’s objectives, to contingent political purposes and to user expectations. The proposed model tries to balance legislative indications with conflicting objectives achieved at different times.

As recognized at the international level, the principal aims of watershed investments consist in regulating water supply and ensuring the permeability of the territory. If properly designed, they can produce other effects—ecosystem services—such as protection of existing blue infrastructures, soil erosion prevention, groundwater-level preservation, and renewable energy-food provision for local community in the city. Especially in contexts with different urbanization levels, these interventions play an important role in the production of hydrological services (e.g., household utilities of drinking water) and renewable energies. To ensure sufficient water resource level in urban area, the implementation of forestry projects allows obtaining more permeable soil surface for better water supply and quality, that can also be used for household practices. In literature, the integration of forestry practices with watershed planning is known as urban watershed forestry projects (UWFPs). Although the International and European directives highlight the requirement to promote sustainable practice to improve water quality and supply for the community requirements, the UWFPs are rarely considered as priority action. In the present research work, an economic evaluation model for UWFP was proposed. The model aimed to individualize the optimal location of urban forestry projects in order to maximize the permeable soil useful to regulate the water resource management taking into account the specific socio-economic situation and the water supply quality and level. The use of multi-criteria evaluation logic allows characterizing the proposed case through a mathematical system with algebraic linear function between financial variables and parameters on ecosystem services regarding water resources regulation and renewable energies production. The mathematical system is written in the programming environment using optimization algorithms. The advantages and limits of the analysis tool as well as future research perspectives were described in the last part of the paper.

Investments in the water and energy sectors are characterized by multiple financial risk components which significantly affect the feasibility of the interventions. What are the acceptability levels of this risk? The objective of the paper was to define a protocol for project risk management. The idea was to introduce two thresholds for financial risk: the acceptability threshold and the tolerability threshold. These thresholds were conceptually borrowed from the As Low As Reasonably Practicable (ALARP) principle, according to which a risk is ALARP if the costs for its mitigation are not disproportionate to the benefits that can be achieved. These risk levels are useful to guide the analyst in assessing the economic viability of investments. For the estimation of acceptability and tolerability thresholds, we proposed a methodology based on the statistical analysis of the profitability indices of the sector companies operating in a given territorial context. An application to water and energy projects in Italy makes it possible to verify the effectiveness of the defined protocol.

This paper illustrates the approach used in some case studies, located in Calabria, South of Italy, for the construction of a Sustainable and Integrated Energy Strategy (SIES). The construction of the SIES involves the use of monetary and non-monetary evaluation techniques to identify the optimal mix of actions to be undertaken in the energy field, in relation to the specific characteristics of each individual municipality. The actions deal with both public and private subjects. In the case of private individuals, the SIES, as co-benefits, intend to constitute a measure to combat depopulation, favouring the achievement of conditions of convenience for residence in small municipalities.

For the managers of the integrated water service, the program of interventions (PdI) is particularly important for the financial success of the management project. Through the PdI, the integrated water service manager identifies existing critical issues and tries to overcome them through investments in infrastructure development and improvement of the quality of the service provided. The solutions adopted fall under the tariff construction mechanism, conditioning the economic formula that determines the tariff increase coefficient. Therefore, the ex-ante evaluation of the risks associated with maintenance, and new construction work is of enormous importance. The objectives of the study were twofold: to apply for the first time a model inspired by the recent bibliography on risk assessment in the civil projects sector to the integrated water service sector, which supports the manager in the risk analysis of the projects that might result during the intervention program; to make infrastructure management more efficient, reducing maintenance costs and increasing profits. This model integrates the ALARP technique, mainly used in high-risk sectors to estimate the loss of human life, with the traditional risk analysis of investment projects. It allows the integrated water service manager to identify two operational, tolerability, and investment acceptability thresholds, useful to define areas of action characterized by greater technical–economic feasibility.

Water resources represent a common good of limited availability due to climate change, pollution, and losses. As in various parts of the world, critical elements are also present in Italy. The country holds the European record for drinking water consumption. This waste is encouraged by rather low-water tariffs. Furthermore, the investments necessary to upgrade the water networks are amongst the most contained in Europe since they are financed almost exclusively by tariff revenues. In the Italian panorama, awareness campaigns for the rational use of water resources promoted by the managers of the integrated urban water management (IUWM) have not had the desired effects. It is necessary to identify more effective communication strategies to achieve a reduction in losses. For example, the IUWM managers could sponsor the initiatives of associations and organizations aimed at promoting the optimal management of water resources. In this work, a model was proposed and validated through a case study. It enables IUWM managers to measure the degree of user satisfaction following the sponsorships mentioned above. The model considers the theoretical profits generated by sponsorship as a proxy for the level of the consent of users towards the promoted initiative. The aim was to demonstrate how this type of sponsorship increases the good reputation of IUWM managers amongst stakeholders and leads to a reduction in the risk of users’ insolvency. It is also considered as a reward mechanism for managers who invest in sponsorship represented by the increase in the water tariff.

Today, most irrigation systems consume energy and a large part use groundwater at rates higher than the aquifer recharge, thus forcing farmers to pump at ever lower levels (more energy consumption, and thus higher cost). The energy consumption of irrigation systems is mainly considered as a technical challenge with the objective to improve its performance. In this work, we proposed to evaluate the energy requirement of irrigation systems and analyze the results through a functional perspective. A bibliographical review was sorted based on the successive evaluation of environmental impacts of irrigation infrastructures and the direct energy demand in relation to water paths. As food, water, and energy issues are interdependent, a new conceptual framework was proposed to discuss the results and support the decision-making process. Adding a social-ecological dimension to the engineering issue of maximizing water productivity balanced with energy efficiency offers many perspectives toward the consideration of agriculture as a provider of public goods.

This work falls within the scope of the energy-for-water branch of the water-energy nexus and is a contribution to better understand the available water and endogenous energy resources in the Algarve region. Time series for water resource availability, solar, and wind power generation potential in the Algarve between 2004 and 2014 were analyzed. Complementarity relations among their trends and seasonal cycles were identified that could improve the efficiency in use of endogenous renewable energies in groundwater pumping.

West Africa has plentiful renewable energy (RE) resources with potential to support economic growth, but numerous energy-related challenges persist. Rural areas are heavily reliant on biomass for everyday needs, and the region has a history of extreme events, including the severe drought in the 1970s and 80s, that impact water availability and access, agricultural productivity and food security. Despite a number of recent programs, energy transitions in the region remain poorly understood. With this motivation, START implemented the Promoting Gains in Renewable Energy project (ProGREEN) in West Africa to identify key enabling and constraining factors for the development and spread of RE, and for recognizing the broader development outcomes linked to RE access. During 2019, ProGREEN gathered multisector and multidisciplinary experts from Burkina Faso and Senegal to embark on an integrative and participatory assessment effort including an intensive literature review, individual interviews, and focus group discussions with grassroots actors of decentralized RE projects. The assessment found access to RE in remote areas was enabled by numerous factors including availability of RE sources, government efforts to improve policy and regulatory frameworks, and falling prices of solar equipment. RE access is found to bring significant improvements to the living conditions of local communities. However, insufficient funds, too few qualified technicians, lacking quality control for equipment, and insufficient engagement of local communities were found to hinder RE development. Findings suggest sharpening technical and financial skills, updating best practices, and integrating research development and cooperation among actors in the renewable energy field.

Buildings evidence potential water and energy savings of about 30–50% and 50%, respectively, accompanied by the consequent reductions on greenhouse gas emissions (GEE). Comparatively to energy efficiency, water efficiency still lacks well-defined structural strategies to improve building resilience to climate change within the European territory, including water scarcity, such as the identification of improvement measures and the required investment solutions for the installation of water efficient products and equipment. In addition, the water and energy nexus should be addressed more extensively. The Coleopter project (2019–2022), co-funded by the Interreg Sudoe European Program, encompasses the general objective of contributing to better energy efficiency policies in public administration buildings. The paper focuses on the importance of conducting integrated energy-water auditing approaches in public buildings, with a new comprehensive auditing scheme developed and tested at a workshop, to be further validated in four demonstrator buildings.

This study focuses on the challenges that governments face in addressing water equity and efficiency. Specifically, it analyzes the implementation of new water governance in post-apartheid South Africa and the central and local governments’ responses to water reform challenges. Using secondary data collected from the digital database LexisNexis, we find that the South African government has made juridical, organizational, and institutional changes to achieve a progressive realization of the right to water and to increase the financial viability of water service. First, the central government has made juridical changes such as the establishment of the 1996 Constitution that recognizes the human right to water and the 1998 National Water Act that abolishes the concept of riparian rights. In addition, the government attempted to build an equitable share of fiscal burdens between the central and local governments under the objective of decentralization. Second, organizational changes have been made to de-politicize water entities as well as transform “non-payment culture” under public water provision which became prevalent as a political contestation over discriminatory rules and poor service provision to black areas during apartheid. For example, the city of Johannesburg has created Johannesburg Water company, a corporation unit that has been owned by the city government but operated under the private business law. This corporatizing process results in improved operational efficiency while posing theoretical and empirical risks to equity considerations and democratic governance. Third, new institutional approaches including free basic water, prepaid meter, and increasing block tariff have been implemented to meet a basic human need and to achieve partial cost recovery at the same time. The case of South Africa water reform indicates that achieving a human right to water is in tension with financially viable water services within a corporate structure.

The influence of resources such as water, energy, land, and food on each other prompted global communities to investigate their role in the sustainable development discourse and develop contemporary measures to address interlinkages between these systems. The current study sought to understand and explore the WECC nexus in South Africa, with the view to promote a holistic and coordinated approach in its analysis. This was achieved within the discourse of Integrated Water Resource Management (IWRM) framework. This approach was driven by the centric role that water plays towards energy generation and other subsectors of the economy despite its scarcity in the country. A mixed-method approach was applied to verify and apprehend the challenges emanating from this nexus. The study revealed that, despite limited understanding and lack of collaboration amongst key stakeholders, the interlinkage between the systems of water, energy, and climate change is inevitable in South Africa. Moreover, the results of the study shows that, like most communities around the globe, South Africa is still lagging in research and development of policies aimed at holistically managing this nexus. The study recommended that South Africa adopt a water-centric approach to improve evidence-based institutional and policy framework to address the myriad challenges of this nexus in a holistic and integrated manner. Furthermore, an effective stakeholder engagement which will result in a collaborative and coordinated decision-making process, and data management systems should be promoted in the country.

Concerns about water and energy security have enhanced the water–energy nexus studies. However, even being well explored, some crucial aspects lack further analyses, such as the historical background of the relationship between the resources. This kind of analysis provides an in-depth understanding of the current situation and future perspectives and must, therefore, be included in WEN investigations. Based on this motivation, the present article analyzed the biggest Latin American city, São Paulo, Brazil. We linked the ongoing water crisis in the region to the jeopardizing of the energy sector at the beginning of the electrification process. Besides illustrating the influence of the historical process on the present events, this brief article aimed to urge the water–energy nexus researchers to include other aspects in their analysis.

Urban agriculture can play a fundamental role in the development of sustainable cities since it allows meeting the increasing food demand by reducing the critical issues related to the current food supply chain, on the one hand, and bringing about several environmental, social, and economic benefits. This study analyzed the main urban farms’ typologies and the systems required to integrate them, with a design hypothesis in a former industrial complex near the Archaeological Park of Paestum (SA, Italy) as support. Results demonstrate how farming integration may be useful to rehabilitate unutilized urban spaces, thus integrating them into the city’s processes. These practices allow bringing natural processes into the urban environment while reducing some of the environmental issues and promoting social welfare and the creation of new economies.

The MENA region (the Middle East and North Africa) extends across the eastern Mediterranean, the Middle East, and North Africa and is home to some 500 million inhabitants. Observations attest for the fact that climate change in the Mediterranean Basin, in general, and in the MENA countries, in particular, exceeds global mean values significantly. Future projections of climate change, based on numerical model results indicate that this trend will continue in the near future. Climate change will result in significantly increased demands for water and energy, particularly in urban settings and major cities in the region. The general economic development, rapid population growth and increasing urbanization, changes in lifestyle, and shifting consumption patterns are likely to exacerbate these demands. There are strong linkages between the provision of water and energy. Maintaining water and energy security in the MENA region, therefore, needs holistic considerations of these issues in the framework of the water‒energy nexus (WEN). The nexus approach focusses on the interdependencies and interrelationships between water and energy provision and consumption. It allows the specification of suitable mitigation and adaptation strategies and measures aimed to minimize the impacts of climate change and enable a sustainable future in the MENA region.

The promotion of SDGs is encouraging countries to move towards devising locally adaptable measures to promote sustainable development. The practice of addressing sustainable development at the level of the individual sector, in silos, is not viable. Based on the success of the IWRM concept, several methodologies have been promoted to encourage integrated approaches; the WEF Nexus being one such approach. The present study was conducted in three stages: First, a critical assessment of the Water, Energy and Food sectors in Mauritius was carried out. Next, an iterative survey was undertaken using the Delphi concept, an iterative process, to get consensus amongst stakeholders. This was followed by case study analysis using the FAO Rapid Appraisal tool. The critical analysis of the three sectors indicated that though the nexus concepts do not form part of decision-making, the existing logistics are strong and the WEF concepts can be implemented with success. The FAO method enabled users to build the complexity of the nexus as they got further understanding of the process behind the nexus approaches. The choice of the indicators was found to be key to the successful implementation of the WEF nexus. The Delphi survey confirmed that local stakeholders’ participation in the decision process can be varied but through iterative surveys, one can eventually reach consensus. Overall, the study confirmed that the WEF nexus can be implemented with success in Mauritius, but will require a strong stakeholders’ commitment, to develop smart indicators accepted by all parties. This study can guide the process.

One of the most important sectors in Sub-Saharan Africa (SSA) is agriculture. This sector ensures food security, supports livelihoods, and creates jobs for a large number of the population within this region. In Nigeria, the situation is not different. Across the Sudano-Sahelian zone in Nigeria, crop productivity is beginning to feel the impact of the changing climate in terms of yield and socio-economic livelihood. This study aimed at understanding the effect of the cycles of atmospheric variable—rainfall on crop production (maize and millet) within the Sudano-Sahelian belt of Nigeria. This study follows a historical-future pattern using satellite-based rainfall datasets. The historical, current, and future datasets were downloaded from https://esgf-node.llnl.gov/search/esgf-llnl/ using the CORDEX domain. The crop data were downloaded from FAOSTAT. The future dataset was presented across three representative concentration pathways (RCPS), 2.6, 4.5, 8.5. The pathways confirmed a slight increase in the rainfall amount across the zone within the RCP 8.5; this has severe consequences on these two crops especially millet. Continued variability in rainfall patterns will severely affect crop production and in turn, lead to insecurities in terms of food supply, poverty, stressed livelihood support, and dwindling economic production. There is a need for integrated water-energy management schemes to help manage future events and create a more food-secured society.

A water conservation indexing using availability and accessibility was proposed in order to have an index that is reliable, consistent, free of site character, and easy to interpret. A year simulation of the heating ventilating and air conditioning (HVAC) system of Suranaree University of Technology Hospital (SUTH) main building was conducted for the case using TRNSYS. Water availability was applied to show the total amount actually or potentially being harnessed during the process. Accessibility indicates the fitness of the available water. The results show that indexes of the water conservation of the system in 22, 24, and 26 °C temperatures setting are around 50%. It implies that there are amount of unused water. The higher the temperature setting is the less conserving the system becomes.

Water and energy nexus concept is a fundamental new paradigm to apply to improve sustainable development policy also in connection with concerns about global warming. Water and energy are closely interconnected with each other especially in wastewater treatment plants (WWTP) where the scope of the plant is in fact the treatment of wastewater and to due this huge energy consumption is required. In a world where the effects of climate change are increasingly evident, it is therefore essential to control the environmental pressures of the WWTP with a view to making it sustainable. Different analytical tools are nowadays used to assess the environmental performance of the industrial plants. Among them, carbon and water footprint represent the two widely applied methods, through life cycle analysis (LCA). The research presents and discusses the assessment of environmental performance for a real big WWTP by applying the water and carbon footprint, with the aim of identifying and avoiding critical elements and increasing their environmental sustainability. The experimental results highlight the strengths and weaknesses of the investigated methods, pointing out the usefulness of applying them in an integrated manner in order to have the global view on the various components examined.

The growth of gas emissions and concentrations, which resulted predominantly from the combustion of fossil fuels, is widely recognized as the leading cause of the increases in global climate change. Urbanization is one of the more relevant reasons for this phenomenon, especially in the countries facing recent urbanization. According to the framework mentioned above, many studies analyse the relationship between electricity consumption and urbanization. Nevertheless, energy consumption and electricity consumption, specifically, are studied in metropolitan areas, while the small and medium-size urbanization are scarcely studied in this perspective. The present contribution describes the results of ongoing research on urban form in household electricity consumption in Italy. The empirical analysis aims to verify whether exists a significant statistical correlation between urban density and households’ electricity consumption in 112 Italian provincial capitals. The analysis confirms the existence of a robust statistical correlation between electricity consumption and urban density. The higher is the density, the less is the electricity consumption per capita. The results are partially counter-intuitive considering the existing literature on the topic, but it is worth underlining two specific features: on the one hand, the “urban heat island” concept considers the overall energy consumption and not just the electricity one; and on the other hand, it suggests the existence of a threshold for which the relationship is reversed in the metropolitan areas. Lastly, in the same way, results confirm the empirical research highlighting the higher marginal costs of public services in less dense territories.

Drought, flooding, and other climate change impacts have led to rural–urban migration. The emigration to urban areas has put pressure on available resources, thereby increasing scarcity and changes in lifestyles. The overpopulation of urban centers accelerates land use patterns, food and water insecurity, infrastructure overstretching, and urban slum creation. In the process of providing more sufficient and organic food to feed the increasing urban population, farmers resort to chemicals such as pesticide and fungicide. Likewise, unplanned human slums and unregulated industries generate lots of known and unknown emerging contaminants that pollute urban soils and water sources. These emerging contaminants flow into streams and river systems and end up as bottom sediments. The contaminant recycling threatens the environmental sustainability through consumptions of heavy metals and emerging contaminants. The research thereby seeks to address the impact of procedural assessment techniques of rapid urban development on water security and environmental sustainability. Remote sensing, GIS, and geochemical investigation and modeling techniques were employed for environmental monitoring and characterization. The results reflect series of urban activities and their impact on the environment and water sources. Furthermore, an environmental sustainability model was developed to classify, predict, manage, and mitigate the environment deterioration for sustainable water and environment.

Current research was performed to find out the relationship between temperature, rainfall, and salinity gradients in pond, canal, and river water together with deep tube well water of Khulna, Bangladesh. Temperature showed an increasing tendency and rainfall showed the decreasing trend with time. Water was collected from Batiaghata, Dacope, and Koyra Upazila. A total of 51 water samples were collected to determine electrical conductivity, salinity, and the concentrations of calcium (Ca) and magnesium (Mg). The concentration of the mentioned parameters was very high at different points as compared to the standard value set by Bangladesh Bureau of Statistics and World Health Organization. Salinity was the highest in the southern part and was the lowest in the northern part. The river water contained the highest salinity, and pond water contained the lowest. Salinity trend could be ranked as river water ≥ canal water ≥ deep tube well water ≥ pond water. The study could be very effective to know the present scenario of salinity and to find out further effective solution in this region.

Industrial and municipal wastewater treatment has the potential of providing considerable quantities of freshwater for different purposes. Prior to its usage, heavy metal ions elimination from treated wastewater must be ensured to evade their toxic and severe impacts on the water ecosystem and humans. For this purpose, graphene oxide (GO)/manganese oxide (MnO2) nanocomposite was prepared in this study and used for adsorption of toxic metal ions from wastewater. This material was characterized using SEM, EDX, TGA, and FT-IR, among others, and their potential in toxic metal ions adsorption was evaluated. The new nanocomposite showed the presence of a high density negatively charged functional groups/active sites. This has the potential to enhance the adsorption of various metal ions and thus, their practical application in wastewater treatment.

Global water demand has pivoted potable water production to alternative methods such as desalination. Membrane distillation is a viable seawater purification method in which hydrophobicity is one of the crucial properties needed to obtain optimal process conditions. A super-hydrophobic nanomaterial based on Fe2O3 was synthesized for embedding into a polymeric membrane’s structure. Fe2O3-oleylamine particles were characterized through FTIR, XRD, and TGA, and compared to pure Fe2O3 particles in which successful oleylamine decoration was confirmed. The synthesized particles showed great potential in membrane technology, specifically in membrane distillation.

Biofouling is a major concern in membrane filtration which could adversely have an effect on the overall membrane performance. To address this issue herein, we prepared polyethylenimine-grafted graphene oxide (GO-PEI) as a filler material to be used in the sulfonated polysulfone membrane (SPES). The PEI grafting on GO and successful sulfonation of PES was confirmed by the FTIR spectroscopy. Thermal properties of both polymer and filler were evaluated via thermogravimetric analysis (TGA). Surface morphology of the GO before and after PEI grafting was conducted using SEM and EDX. The presence of large amount of amine groups on the GO surface and the sulfone groups in the SPES are expected to enhance the membranes anti-fouling and anti-microbial properties. Moreover, these groups are also responsible for the strong hydrogen bonding which can improve the mechanical properties as well as dispersibility of the GO-PEI in the membrane.

The influence of CO2 addition and feeding regime (continuous versus semi-continuous) on the removal of Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus, Enterococcus faecalis, and Escherichia coli from three shaded High Rate Algal Ponds (HRAPs) treating primary domestic wastewater (PDW) was studied. The three HRAPs were operated at similar hydraulic retention time of 5 days and shading of 50%. The CO2 addition and feeding regime had no statistically significant influence on the removal of Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus sp., and Enterococcus faecalis, removing 2.39–3.01, 2.07–2.31, 3.02–3.38, and 3.14–3.45 log units, respectively. On the other hand, only the removal of Escherichia coli decreases significantly at a semi-continuous feeding regime of 0.1 h d−1, 2.23–3.29 log units. The productivity and the settleability have been significantly improved at the semi-continuous feeding regime and the CO2 addition, producing 3.94–5.93 g m2 d−1and settleability of 31–36%.

Conventional wastewater treatment systems have a low pathogen removal capacity and are often even being pointed out as hot spots for the development of multiresistant bacteria and genes. Microalgae-based systems, especially the high rate algal pond (HRAP), are sustainable and low-cost alternatives for wastewater treatment, capable of removing pathogens from domestic effluents, mainly Escherichia coli and total coliforms. Other microorganisms, being the most important Clostridium perfringens and Staphylococcus sp., have been pointed out as alternative indicators of disinfection, since they have greater resistance than Escherichia coli, either because of the formation of spores or because of other mechanisms of protection and spreading in WWTPs. The influence of two microalgae strains (Chlorella vulgaris and Scenedesmus acutus meyer), CO2 addition and O2 addition on the removal of Clostridium perfringens and Staphylococcus sp. from domestic wastewater in microalgae-bacterial systems was studied. The removal of Clostridium perfringens (2.5–3.2 log units) and Staphylococcus sp. (1.8–2.0 log units) was higher in the test with Chlorella vulgaris inoculum than Scenedesmus acutus meyer. The addition of CO2 and O2 did not have a significant effect on the removal of pathogenic bacteria. The main mechanism of Clostridium perfringens removal can be through toxins and bactericidal substances produced by the microalgae while Staphylococcus sp. removal also occurs through photo-oxidative processes.

Graphene oxide and multi-walled carbon nanotubes have recently attracted attention, as they have proved to have potential in various applications. Therefore, in this study, a positively charged functionalized multi-walled carbon nanotubes (f-MWCNT)-graphene oxide (GO) composite was prepared by the electrostatic attraction approach, as they are oppositely charged, to test for its potential in wastewater treatment applications. Detailed characterization tests such as x-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), contact angle, and zeta potential analyzer were used to evaluate the interaction between MWCNT and GO as well as the nature of chain growth on the CNT surfaces. The characterization techniques proved the presence of the functional groups on the MWCNT surface and indicated that the composite is hydrophilic. Therefore, it is expected that this composite material would be a great candidate for the wastewater membrane filtration systems.

Membrane bioreactor (MBR) technology has attracted great attention over the last 3 decades and achieved rapid growth in an increasing number of practical small‐ and large‐scale applications worldwide. However, its application in Sub-Saharan Africa as well as in aquaculture was so far limited. The installation and operation of a pilot membrane bioreactor (MBR) in Kisumu, Kenya, adopts an integrated approach by providing an integral, sustainable, cost‐effective, and robust solution for water sanitation, which also meets the demand for clean water in the fish processing industry, aquaculture, and irrigation. The innovative system comprises a pilot MBR coupled with a recirculating aquaculture system (RAS) which is linked to a 14.3 kW photovoltaic (PV) system, including a 30 kWh Li battery storage to supply sustainable energy. The RAS is able to recirculate 90–95% of its water volume; only the water loss through evaporation and drum filter back flushing has to be replaced. To compensate for this water deficit, the MBR treats domestic wastewater for further reuse. Additionally, excess MBR treated water was used for irrigating a variety of local vegetables and could be also used in fish processing plants. The pilot‐scale MBR plant with around 6  m2 submerged commercial UF polyethersulfone (PES) membranes provides treated water in basic agreement with Food and Agriculture Organization (FAO) standards for irrigation and aquaculture, showing no adverse effects on tilapia fingerlings production. A novel membrane module with a low‐fouling coating technology is operating stably but has not yet shown improved performance compared to the commercial one.

The integration of nanoparticles in wastewater treatment technologies has become an attractive topic to improve the membrane’s hydrophilicity, which is a vital membrane property needed for the efficient removal of contaminants. Functionalized graphene oxide (FGO) and oxidized multi-walled carbon nanotubes were used to synthesize FGO/MWCNT-COOH nanocomposite. The components of the nanocomposite were characterized through thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta potential, and contact angle. The characterization tests of the synthesized nanoparticles indicated the presence of functional groups and the good hydrophilicity of the prepared nanocomposite. This nanocomposite with high hydrophilicity has a great potential to be integrated into the membrane matrix used for wastewater treatment.

Aeration has always been considered as one of the most important parameters for controlling a wastewater treatment plant’s (WWTP) performance. A real-case study of performance assessment of a full-scale extended aeration WWTP showed a good efficiency of total chemical oxygen demand (CODt) removal of 91% corresponding to a final value of 70 mg/L, which is convenient to the Tunisian standards of discharge in a maritime environment. However, the total nitrogen removal efficiency was 73% with a total Kjeldahl nitrogen value of 13.8 mg/L in the influent. This was considered low and needed improvement. Thus, the effect of five different aeration conditions on nitrogen removal was investigated at full-scale through the application of different airflow rates ranging from 412 kg O2/h to 670 kg O2/h per tank coupled to an intermittent aeration system. Results showed that the best oxygen transfer rate (OTR) and volumetric oxygen transfer coefficient (KL.a) of 4339.5 kg/h and 55 h−1, respectively, were obtained for an airflow rate of 610 kg O2/h and an aerobic/anoxic time of 1.5 h/1 h. Therefore, increasing the aeration flow rate as well as the time of the aerobic phase allowed good nitrification and denitrification ratios with an ammonia removal efficiency (ARE) of 90.51% and nitrate accumulation ratio (NAR) of 0.45%. At a second stage, a simulation of ASM1 model under better conditions showed a good fitting between the model and experimental results with low root mean square error (RMSE) values. Results also showed an improvement of the model response to the effluent quality in terms of nitrogen prediction with R2 values of 0.99 and 0.71 for ammonium nitrogen (SNH) and nitrate (SNO), respectively.

Synthesis of Fe3O4-Ag nanoparticles (NPs) was implemented via utilizing the method of coprecipitation for synthesizing the Fe3O4 nanoparticles, and reducing silver nitrate (AgNO3) to Ag nanoparticles, and impregnating the Ag NPs into the Fe3O4 NPs. The synthesized composite material was characterized using zeta potential, FT-IR, XRD, the contact angle, and the particles size distribution analysis. The results showed that the Ag NPs were attached to the Fe3O4, and that the composite nanoparticles have positive charge, and exhibit hydrophilic behavior. Such properties make these materials a great candidate for oil–water separation-related applications.

In the last couple of years, response surface methodology (RSM) has been implemented to model as well as refine a range of waste treatment processes, specifically in water and wastewater treatment. RSM analyzes the outcomes of the variables as well as extract their values from the ones which provide the important values. RSM can be used as the optimization method to reduce the number of experiment. Recent information on RSM usage is discussed in this article, specifically in physicochemical wastewater treatment. The theoretical principles and measures for its execution are first outlined. The latest research on its usage of coagulation-flocculation, adsorption, advanced processes of oxidation, electrochemical processes, and disinfection is being examined. This highlights the limitations of the technique. Tries made to improve the RSM by integrating it with other modeling techniques are also listed. RSM can help improve wastewater treatment operation condition, especially physicochemical treatment.

Currently, desalination plants are essential tools for utilizing water from various natural resources like brackish water and seawater. Worldwide, the number of desalination facilities is rising to fulfill the increased requirement for potable water to be utilized for human consumption, public services, and industrial activities. There exist three principle methods of desalination: thermal, electrical, and pressure. Conversely, the brine released will have several negative effects on the surroundings. The current study aimed to give a general awareness into the present progress in the desalination processes through investigating the various available technologies. Different brine disposal approaches are analyzed as well as compared. We have also compared the different technologies based on energy consumption and water production costs. Moreover, we examine the zero liquid discharge (ZLD) technique, its challenges, advantages, operating as well as environmental characteristics, and the up-to-date research progress in this area. In the end, we have briefly analyzed the upcoming research and development approaches for brine management. It was found that this ZLD process is extremely beneficial to the environment with respect to decreasing the pollution caused by the discharged brine and attaining sustainability. Additional pilot or field studies are necessary for validating their commercial-scale performance as well as feasibility in practicing ZLD.

The Sidi Salem dam is deteriorated by silting due to the water erosion-transport-sedimentation mechanism, causing a reduction in the water storage capacity. The objective of this work is the elaboration of the silting map by applying the processing method by subtracting the results from the rasterization of the bathymetric data by interpolation in order to highlight the evolution of the silting at the bottom of the dam. The results obtained show that the spatial distribution of the silting of the Sidi Salem dam is weak in the western part while the silting reaches its maximum in the eastern part of the dam. This irregular distribution of sediments is due to several factors leading to an elevation of the bottom of the dam, the most important of which are erosive currents, the irregularity of the geomorphology of the bottom of the dam which favors the reception of sediments, and the lithology of the rocks.

The production of olive oil in the Mediterranean region leads accumulation of olive mill wastewater (OMW) in large quantities. Besides a high amount of nutrients, OMW contains polyphenols which show phytotoxic properties and are harmful to aquatic- and microorganisms. Reducing toxicity of OMW was performed by pre-treatment with aluminum sulfate and adsorption onto Luffa cylindrica (Cucurbitaceae), which resulted in a reduction of polyphenolic compound tyrosol by 51%. This methodology shows that treated OMW can be utilized as a fertilizer without environmental harm since it contains high quantities of potassium, nitrate and phosphate.

This research was performed to find out the efficiency of water hyacinth (Eichhornia crassipes) shoot powder (WSP) and arum (Colocasia esculenta) shoot powder (ASP) in eliminating chromium (Cr) and copper (Cu) from tannery wastewater (TWW). For this purpose, WSP and ASP were added to standard solutions (SS) of Cr and Cu; and TWW. Elimination of the metals was inspected in batch processes at diverse contact periods with the identical bio-adsorbent concentration of 5.0 mg L−1. The colour was bottle green and the odour was pungent which were totally absent after the application of the treatment. The maximum Cr was eliminated from the SS and the TWW with the WSP were 85.29% and 87.50% (reduced from 12.0 mg L−1 to 1.5 mg L−1), respectively, at 180 min. The WSP impassive the maximum amount of Cu, 87.96%, from the SS at 180 min, whereas 83.35% was the maximum elimination from the TWW at 120 min. The ASP eliminated the maximum amount of Cr, 79.46%, at 180 min from the SS, whilst 77.08% of the metal was eliminated from the TWW for the same. The maximum amount of Cu, 78.57%, was eliminated from SS at 180 min with the ASP whilst 75.0% was the maximum from the TWW for the same. The WSP was more operative than the ASP in eliminating Cr and Cu from both the solutions.

This research was conducted to identify the suitability of drinking water in different sources in the most disaster prone unions in Bangladesh. Saline water is one of the main concerns in the disaster prone Buri Goalini and Gabura Unions, Shyamnagar, Satkhira. Water samples were collected from pond, deep tube well and pond sand filter for physico-chemical analyses to determine its suitability for drinking purposes. The electrical conductivity, total dissolved solids, salinity, sodium (Na) and potassium (K) were determined. Beside these, some other parameters were also determined. Almost all the water samples of pond sand filter were within the desired quality of drinking water in terms of physico-chemical parameters prescribed by World Health Organization and Bangladesh Bureau of Statistics. The pond water of Gabura Union and deep tube well water of both the Unions were saline in nature and not suitable for drinking purposes. Interestingly, pond water of Buri Goalini Union was fresh in terms of EC, total dissolved solids and salinity.

Olive oil mill wastewater (OMWW) is a liquid effluent derived mainly from the water used for the various stages of oil production and vegetable water from the fruit; it is identified as a by-product of the olive oil industry. It has a dark brown colour, strong specific olive oil smell, high organic content and suspended solids, and it is also acidic with a high rate of soluble salts. Moreover, disposal of the OMWW causes serious environmental problems such as soil contamination, water body pollution, underground seepage and odour. This is why the OMWW cannot be discharged in the environment without treatment. In this work, the OMWW from the region of Boughrara (Medenine) was analysed and then treated by coagulation–flocculation. The effect of the obtained treated water, on the physico-chemical properties of the soil in the arid zone of Medenine, was studied. This treated water did not change the main physico-chemical properties of the soil when used for irrigation. During a comparative exploration of the soil respiration kinetic in the presence of OMWW, treated OMWW, tape water and distilled water, it was found that treated OMWW had an intermediate behaviour between OMWW and tape water as it still contained organic matter even after treatment, responsible for a noticeable soil respiration compared to standard sample and to the soil treated with tape water.

To cope with water scarcity, wastewater reuse is one of the most promising supply-management practices. Several techniques are used for the purification of domestic wastewater, and our research work focused on the infiltration–percolation technique, which is a biological treatment process with a culture fixed biomass. The main purpose of the present study was to investigate the performance of this treatment process regarding particularly the removal of nitrogen from the wastewater treatment plant of Zarat. A comparative study was carried out to evaluate the effect of the double filtration (on 50 cm of sand) on the nitrogen removal efficiency, compared to the simple filtration (on 1 m of sand). Three PVC columns (internal diameter 20 cm and length 120 cm) were used to simulate wastewater treatment by media-based filtration. Each column was packed with a drainage layer (medium gravel), a transition layer (fine gravel), and a filtration layer (sand). Operating the two filter columns in series (50 cm of sand) resulted in a better effluent quality than a simple filter column (1 m of sand). The total nitrogen and ammonia removal efficiencies by filter columns 1 and 2 in series amounted to 97% and 96%, respectively. Analyses of the percolating water showed that overall removal of nitrogen increased significantly with the infiltration depth, emphasizing that the highest nitrogen removal efficiency occurred mainly in the upper layers of the filter bed. However, after a double filtration, the decrease in the total nitrogen and ammonia was accompanied by an immediate increase of significant nitrate content ( $${\text{NO}}_{3}^{ - }$$ ). These results are very encouraging for the urban wastewater treatment for agricultural reuse, even with a high residual NO3 concentration since it will be an interesting contribution to fertilization in nitrogen nutrients since they are well assimilated by plants.

Membrane bioreactor (MBR) is an alternative to the traditional-activated sludge processes. It is considered as one of the most significant innovations for wastewater treatment since it is much more reliable and efficient. However, membrane fouling and its consequences on plant maintenance and energy consumption limit the application of this promising technology. Recent studies have attempted to control the membrane fouling by applying electrochemical processes to MBR (eMBR). This obtained solution is not only a promising technology for fouling control but also increases the system purification efficiency, allowing the reuse of the treated water. Other more recent studies have highlighted how the use of low-cost self-forming dynamic membranes (SFDM) can exploit the membrane fouling by increasing the efficiency of the system. These membranes differ from the traditional ones in the high pore size that ranges from 10 to 200 μm. Thanks to these membranes, costs are drastically reduced; however, the large size of the pores limits their application since the effluents obtained in the beginning of the process are not of good quality. In the present study, the performance of an innovative SFDM, integrated into an electro-MBR, was studied. The experiment was conducted on a pilot scale using real wastewater from a full-scale wastewater treatment plant. Both of the pollutants removal efficiency and the fouling formation have been evaluated. This extremely innovative hybrid system is able to achieve high effluent quality, significantly reducing the scale and, at the same time, the high costs of the traditional membranes.

Green-based materials are currently considered as one of the most vital areas of sustainable development. In the present study, a water-soluble chitosan-based electrospun nanofiber membrane was prepared as a green nanocatalyst for water purification. It was noticed that the water-soluble chitosan nanofiber’s diameter was smaller and more hydrophilic (water contact angle) compared to the water-insoluble nanofiber membrane. The results show that more than 80% of methylene blue dye could be removed by the water-soluble chitosan nanofiber membrane, while only 60% of methylene blue was removed by a water-insoluble nanofiber membrane. It can be assumed that the present work will inspire the development of green nanofiber membranes to combat water pollution.

This research work reviewed the potential of raw materials such as various clays and industrial ash for the fabrication of affordable ceramic membranes. These materials were used for preparation of microporous supports for microfiltration and ultrafiltration membranes. Compared to conventional ceramic membranes, these readily available natural or waste materials can be obtained at no cost or low cost. Furthermore, sintering can be achieved at lower temperature, thereby reducing the energy consumption by over 30%. Overall, the use of alternative raw materials for ceramic membrane manufacturing is promising in terms of raw materials cost, energy consumption for sintering and contribution to a circular economy.

In Mediterranean regions, water resources suffer from important hydric stress which produces subsequent negative climate change effects. Such is the hereby presented case, taking place in the lower river basin of the Mijares River, in the eastern Spanish region of Castelló, in the Júcar River Basin District—Spain. This paper presents the case of integration and use of reclaimed waters coming from wastewater treatment plants (WWTPs) and the photovoltaic (PV) energy production, as a solution to a double problem in this region. The first problem deals with a water scarcity impact in the lower stretch of the Mijares River, where the environmental flows are not totally covered, making the river flow disappear and breaking the river course’s community. The second problem consists of marine intrusion in the coastal aquifers (Palancia-Mijares Interfluvial aquifer), caused by the overexploitation of groundwaters for irrigation purposes. This kind of solution requires a long-term study and planning process and necessitates an inter-users costs assumption transfer process, where the main users of water resources, are the main impact sources, too. Thus, irrigators, as well as water authorities and managers, must contribute jointly to give a solution to, both, an environmental problem, and a problem of water scarcity and unsustainable water usage. In this case study, we investigate an integrated water management solution which may lead to big investments in the establishment of the necessary facilities in the short term that will be offset and even turn advantageous in the long run as this solution reduces the operation costs; thus, making the current irrigation uses sustainable and economically worth over time.

Membrane photobioreactors (MPBRs) can be applied as promising advanced treatment of effluents from conventional activated-sludge plants, focused on the recovery of nutrients present in wastewater instead of using energy for their removal. A lab MPBR equipped with a submerged hollow fiber ultrafiltration membrane has been operated with a secondary effluent and without microalgae inoculation. The first phase was focused on promoting spontaneous microorganisms growth and rising a stable suspended solid concentration, while the second phase was dedicated to studying the reactor performance and membrane fouling at a stationary state. The microorganisms that spontaneously developed in the systems were identified as Scenedesmus sp. and diatoms. In addition, suspension filterability tests were carried out following the step flux methodology varying the imposed flux from 8 to 30 l/h·m2. Stable MLSS content of around 1200–1400 mg/L in the MPBR was achieved after the acclimation phase of 45 days operating at a hydraulic retention time of 18 h and solids retention time of 40 days. In both phases, membrane fouling behavior was similar, with around 80% of reversible nature and easy removal by physical cleaning and completely independent of the suspended solids content. Regarding the reclamation efficiency, dissolved organic carbon was not significantly removed while the nitrogen load was reduced by 20%. The nitrification process was mainly due to nitrifying bacteria.

Perfluorinated alkylated substances (PFAS) in landfill leachate can contaminate the neighbouring soil and groundwater and pose serious health concerns to human and ecosystems. It is the case of Veneto region, Italy, one of the most important sites of water contamination in the world. This water contamination was caused by these substances, due to a chemical industry in particular, which has poured its waste into the ground and surface water for decades. This contamination has extended to reach landfills and consequently, the produced leachates require a special treatment for PFAS removal. One of these landfills is located in Sant’Urbano, province of Padua, managed by GEA s.r.l., member of Greenthesis Group. GEA has decided to install an on-site leachate treatment plant using the reverse osmosis technology followed by evaporation in order to concentrate pollutants for final thermal destruction. A pilot test was performed before in order to carry out the PFAS removal from leachates. The evaluation of the performance of the full scale plant was measured by tracking the evolution of some parameters like the chemical oxygen demand (COD), the biological oxygen demand (BOD5), the total solid (TS), and PFAS. The different degradation rates for COD, BOD5, and TS removal were 99.2%, 99.1%, and 95%, respectively. The PFAS removal was also verified, achieving a degradation rate of about 100%.

Water/energy nexus is becoming more and more interrelated year after year and several hydric-stressed countries should be prepared to face the fresh water scarcity. Conventional desalination is becoming more and more efficient and cost effective, though energy intensive. In this paper, a thermal desalination process driven by geothermal energy was investigated as a sustainable solution for remote communities of southern Tunisian. Therein, the majority of well water is brackish. The first part of this paper was an overview on the current state of the worldwide desalination and the recent development in desalination powered by renewable energy sources. We focused on the progress made in the integration of the geothermal water as energy input for thermal desalination processes. In the second part, the Tunisian geothermal potential was estimated. Thermal waters having temperatures between 30 and 80 °C characterize the geothermal potential of the southern Tunisia. The technical properties of the local existing wells promote the feasibility of geothermal brackish water desalination based on multi-effect distillation process. The geothermal energy was proven to be appropriate to supply remote communities of southern Tunisia with fresh water. Moreover, it is environmentally friendly and economically competitive. Geothermal energy, when available with sufficient enthalpy, is best suited to continuous thermal desalination.

Citizen science-based (CS) water quality monitoring (WQM) is considered as an innovative approach to enhance the hydrosystems’ monitoring. The main objective of this study is to assess the salinity monitoring adopting CS-based WQM for Medjerda watershed, the main hydrosystem of Tunisia, using test kits. The study focused on total dissolved solids (TDS) and electrical conductivity (EC) of water. 96 samples were collected to assess water salinity, from 12 sampling sites located in the Medjerda river or its main tributaries. Water salinity monitoring tests, for wet (January–March 2020) and dry (June–July 2020) periods, were performed by test kits. Regression analysis, determination coefficient (R2), F test, and Cronbach’s alpha (αC) test were performed to statistically assess the difference between the citizens’ dataset and the standard values. Results show that TDS and EC-sensitive test kits were reliable for measuring a wide range of concentrations of 207–6073 ppm and 415–9999 µS/cm, respectively. There was also a good agreement between the citizen-based outcomes and the analytical methods. Nevertheless, the reliability depends on the citizen and the parameter to be tested. Finally, the rapid and simple measurements using the test kits appear suitable to be used as CS-WQM for Medjerda hydrosystem if instructions are strictly followed, and test kits are correctly used. With more consistent training, the test kits should allow for reliable, sensitive, and precise monitoring of water quality.

This work reviewed the importance of membrane filtration component in the total life cycle cost (LCC) of anaerobic membrane bioreactors (AnMBRs). A limited number of studies have focused on detailed membrane system costs in estimating LCC of MBRs, but the significance of membrane choice is evident. Conventional polymeric and ceramic membranes are well established in MBR applications; however, membranes fabricated from wastes such as coal fly ash, sugarcane bagasse fly ash, and rice husk are receiving attention because of lower material and manufacturing costs. These cheaper waste-based membranes have the potential to impact capital cost, but their operational aspects, especially in the long-term, need to be established. Re-use/recycle as well as disposal of such waste-based membranes after end-of-life is another key LCC aspect that needs to be addressed.

The tourism industry has come under intense scrutiny of late in southern Africa and the world for its contribution to the vulnerability of host communities to the impacts of climate variability and change. The increased frequency of extreme droughts that saw Cape Town and other parts of South Africa going for a prolonged period of water shortages require new thinking and approach to water resources management to achieve sustainability. The aim of this study was to examine how the tourism and hospitality industries in South Africa have responded to the threat of water insecurity to ensure sustainability. To this end, the study used primary and secondary data from annual-integrated annual reports of leading hotel chains to address the research objectives. The study found that the risk of water insecurity within the tourism industry and increasing demand for sustainability coupled with the need to increase profits has forced the tourism industry to adopt water-saving measures. To achieve the ideals of Sustainable Development Goals 12 and 13 on clean water and sanitation and climate change, respectively, the tourism sector has retrofitted its bathrooms, invested in water recycling and reuse. Other measures include the installation of drip irrigations and using drought-resistant flowers in garden landscaping as water-saving and conservation initiatives. The study provided critical theoretical and water management implications for the tourism and hospitality industry. The study recommends continued investment in water innovation and research.

The lack of freshwater resources has prompted researchers to find other water desalination processes. In this article, a new experimental set up for humidification–dehumidification operating on the principle of an airlift pump was experimented. Experimental work investigates the main operating parameters of a proposed desalination process working with an air humidification—dehumidification method. The principal objective of this investigation was the determination of the humid air behavior through single stage of an airlift humidification–dehumidification system. The experimental work studied the influence of the operating conditions such as the water temperature and the initial level of water in the riser and the airflow rate on the performance of the setup. The experimental results show that the production rate of the system increases with the both increase of the sea water temperature and the airflow rate. The productivity of the system is strongly affected by the sea water temperature, airflow rate and slightly affected by the initial level of water in the riser. Within the studied ranges, the maximum productivity of the system reached to 4 kg/h, at Tw = 85°C and m a = 5 kg/h.

Biochar from lignocellulose-rich (woody) agricultural wastes has previously been shown to improve water holding efficiency and plant growth when added to low-quality soils. However, the potential of biochar from cellulose-rich feedstocks, and biochar’s potential with already excellent quality soil, is limited. In particular, it is unclear to what extent cellulose-rich biochar amendment from food waste is effective to improve the quality of potting mixture (PM), promote plant growth, and reduce water demand. Therefore, biochar was produced from cabbage wastes at 360 °C by pyrolysis and characterized along with PM. The plant growth rate was tested for basil (Ocimum basilicum) and bermudagrass (Cynodon dactylon) in 0% (control) and 4% biochar for 50 days. Biochar addition of 4% to PM creates a more neutral pH. Biochar addition increased basil plant height by 20%, though not statistically significant. Biochar showed no notable difference in the number of leaves and germination rate. Grass height did not show considerable improvement. However, there was an absolute increase of 21% for the water holding capacity with a 4% biochar amendment. The results suggest that the application of food waste biochar has some potential to improve even high-quality soil, though the benefits, if realized, will be significantly more limited than those previously reported for poor quality soils.

This study investigates the willingness to accept compensation values for crops conversion programs in rural Tunisia and explores factors that would affect it. In this area, there is a conjunctive use of surface water and groundwater where wells are contaminated by saline intrusion, while surface water quantity distributed by the association is limited. Based on 81 farmers, survey data collected in Diar El Hajjaj irrigated area. A Tobit regression model was applied to analyze the data. The results show that farmers’ willingness to accept values are not only affected by farmers characteristics (age, tenure status, family labor, and operating capital), and the amount of proposed values, but are also influenced by non-economic factors, such as groundwater salinity. Our finding may provide the government with a new measure to cope with water shortage.

Natural ventilation is an efficient method that can maintain the microclimate in greenhouses at the required level for growing plants. This technique can also reduce the energy consumption required for mechanical ventilation. The aim of this study is to investigate heat and mass transfer inside a wind-driven naturally ventilated gable-roof greenhouse with plants in hot and dry climatic conditions using numerical modelling. The three-dimensional geometry of the greenhouse was created with Solid Edge ST10 software. The outdoor temperature and relative humidity were 27 ℃ and 10%, respectively. The air velocity at the greenhouse roof was 13.2 m s−1 and an atmospheric boundary layer profile was adopted for the inlet wind velocity. The greenhouse included one row of crops at the level of the openings. The crops were modelled as porous media. The porosity of the crops was 0.37. The simulations were performed using ANSYS Fluent 18.1 commercial tool. The Navier–Stokes governing equations were discretised by a finite volume method, and flow fields were estimated using the steady Reynolds averaged Navier–Stokes model in combination with the standard k–ε turbulence model. Variations of air temperature, relative humidity and turbulent dissipation rate (ε) of the air were analysed. The results of the study showed that air temperature inside the greenhouse increased by 1.2 ℃ as it approached the plants. On the other hand, an increase of 74% relative humidity of the air has was observed at the vegetation level due to the transpiration of the plants. The study also showed that the turbulent dissipation rate increased by 85% due to the amount of heat released by the plants that increased the turbulence of air. Future work should explore the effect of varying vegetation parameters on ventilation performance.

Olive Mill Wastewater (OMWW) is the main problem of the olive industry. It is characterized by a high moisture content which affects its direct valorization. The solar greenhouse drying of this waste seems to be an effective and low-cost pretreatment to obtain a potentially recoverable resource from the resulting sludge. The performance of the solar greenhouse drying in the treatment of this waste was examined. A 2D modified lean-to greenhouse dryer was thus numerically investigated using the finite element method of the COMSOL Multiphysics software. The temperature and velocity profiles as well as the drying efficiency inside the greenhouse dryer were presented and compared to those found numerically under open sun. The results allowed a better understanding of the evaporation process of OMWWW inside the dryer. An increase of the OMWW and air temperatures and a better air circulation were recorded inside the greenhouse dryer compared to that under open sun which allows faster and efficient OMWW drying. The overall calculated drying efficiency inside the greenhouse dryer and under open sun reached, respectively, 41.7% and 34.3%, thus highlighting the importance of greenhouse effect inside the solar dryer. The developed model can be used to investigate the solar greenhouse drying of different products under different operating conditions and to obtain an optimal dryer design.

The current challenges in the fight against climate change and environmental protection require a paradigm shift in the current scenarios for the management of resources such as water, energy and by-products such as waste. These three elements find their meeting point in the production of biogas. The biogas obtained from the anaerobic digestion of the organic substance can be converted into biomethane through the use of upgrade technologies. The paper presents and discusses the state of the art of the main applied biogas upgrading technologies in municipal solid waste treatment with the aim of providing useful information for the choice and application of the best technology in order to maximize the production of biomethane and its energy transformation. The strengths and weaknesses of the principal biogas upgrading technologies are argued. Recommendations and future developments have been reported for the application of these technologies on an industrial scale.

This study was carried out with the scope of resource recovery platform from the food waste-based organic materials in the presence of in situ microfiltration immersed anaerobic membrane bioreactor. Afterwards, ultrafiltration technology was adopted. These microfiltration and ultrafiltration processes successfully removed larger particles, i.e., suspended solids from the anaerobically digested effluent. Moreover, ultrafiltration membranes (50 kDa) can also be recovered with a high concentration of volatile fatty acids (VFAs) and nutrients. Among them, acetic acid was the dominant VFAs compound. These results are highly interesting with respect to recovering a higher amount of VFAs by the use of nanofiltration technology in future consortium.

Accounting for directional water flow is important in evaluating recoverable water resources in fractured rocks. Fracture orientation, aperture, frequency, and continuity affect water flow and could cause flux to vary with direction. Thus, the potential yield of a well in a fractured rock depends on the location of the well relative to groundwater flow pathways determined by the fracture system. Although advances in characterization of fractured rock provide basic data needed for numerical simulation of flow, current technology typically does not incorporate fracture characteristics or their uncertainties adequately. This paper described a two-tier technology for modeling water flow in a fractured rock, based on using two independent analysis codes sequentially. The first code models discrete fractures explicitly, using a statistical fracture distribution model as input, to calculate the spatial distributions of directional permeability and porosity representing the fractured-rock system. Directional permeability is based on the orthotropic model. The second code uses the porosity and directional permeability distributions in continuum analysis to model groundwater flow. The paper evaluated the approach through numerical simulation of a water-flow experiment in a fractured-rock block 20 × 20 × 20 m3. The simulated specimen features a central recharge well and four observation wells in different directions and equidistant from the recharge well. Results from four fracture distribution cases and one recharge rate show the steady-state flow rate in an observation well varies with the direction of the well location relative to the recharge well. The directional effects on flow rates were evaluated relative to the flow rates in an isotropic system (that has no directional dependence).

Since many regions of the Earth underlie pronounced seasonality, the availability of rainwater is often limited to a short period. This imbalance is additionally intensified by climate change and increasing pressure on land use in dryland ecosystems. Sand dams have gained attention as an adaptation measure to prevent the runoff and loss of rainwater during the rainy season. Yet, the long-term effects of these structures are rarely investigated. One major challenge is to decouple local ecosystem changes caused by higher availability of rainwater from superimposing long-term trends of climate changes. To tackle this problem, we proposed a method implemented within the Google Earth Engine to utilize time series of Landsat satellite images and track the effectiveness of sand dams over the last two decades. Within this big-data approach, we systematically compared the normalized difference vegetation index (NDVI) in our study area with at a control site in the Makueni District in Kenya. Our results show that vegetation vitality and coverage are higher at sites with matured sand dams. Furthermore, vegetation suffers less and recovers more quickly from extensive dry periods as the Landsat time series of the NDVI from 2000 to 2019 shows. Our findings indicate sand dams as a significant mitigation measure against climate change and their potential to increase the resilience of communities by ensuring water security.

This review reports studies on the reactivation of biomass in anaerobic reactors treating industrial and municipal wastewaters after extended shutdown. The study also identifies indicative parameters of restart potential of anaerobic reactors. After nearly a month of favorable operational conditions (pH and temperature) post-restart, anaerobic reactors have exhibited satisfactory chemical oxygen demand removal (63–95%) and biogas generation, indicating effective microbial activity. These results were corroborated by microbiological studies on quantity and diversity of the methanogenic community. Despite changes in the microbial structure, anaerobic reactors achieved satisfactory performance after restart owing to the adequacy of active microbial population. It was concluded from literature that shutdown does not significantly affect performance despite changes in microbial community of a reactor sludge. Overall, reactors can attain satisfactory performance after a month from restart, under suitable conditions.

Biogas can be utilized for H2 production using steam reforming of biogas (SRB). Biogas composition varies in wide range (CH4 = 45–80%) depending on various substrates. With this view, thermodynamic modeling of steam reforming of biogas has been performed to find out the effect of change in pressure (1–11 atm), temperature (573–1273 K), biogas composition (CH4 = 45–80%), and steam-to-methane ratio (1.0–4.5) on hydrogen production. CH4 conversion of almost 99%, a high percentage of hydrogen in product gas with high H2 yield with zero carbon formation have been obtained at the temperature of 973 K and the steam-to-methane ratio of 4.0 when reformer operated at atmospheric pressure for all biogas compositions studied. Energy requirement (98.37–165.45 kJ/mol) has been determined. Besides, proton exchange membrane fuel cell (PEMFC) generates the electrical power between 129.30 and 253.09 kW from one mole of biogas having compositions between CH4/CO2 = 45/55 and 80/20, respectively.

Solar energy is an important source of clean energy. As the sun changes position during the day from morning till night, and its orbit differs from one season to another. This affects the intensity of the incident solar radiation. A tracking system is used to maximize the absorbed solar energy, and the useful energy gain. This research attempted to develop an indirect force convection solar dryer fitted with a tracking system on the vertical direction. Four different indirect type force convection solar dryer design concepts were presented. One design concept was chosen after a scoring process which consists of a solar collector, a drying chamber, and tracking mechanism. The thermal performance of the final solar dryer design was studied. Several experiments were performed at Suhar city in Al Batina North governorate of Sultanate of Oman. The results show that the maximum air temperature inside the solar collector at 2 pm is 70.3 ℃. In addition, the temperature inside the solar collector is increased by 14% compared to a fixed system. Furthermore, the difference of moisture reduction ratio inside the solar dryer is 71%, compared to open sun which is 29%.

Dwindling freshwater resources and increasing demand have made continuous water supply a constant challenge for many countries. This problem is even worse for developing countries where the population is growing at an alarming rate and cities are becoming more and more urbanized. An overall water demand corresponds to the high quantity of wastewater produced, and its pollution are continuously increasing. Wastewater treatment and reuse have been recognized as important steps in ensuring sustainable supply of water resources. The dispersed body of literature casts shadow on the performance of developing countries on wastewater treatment and reuse. This paper reviewed water withdrawal and wastewater production, treatment, and reuse trends in developing countries focusing on Africa and Asia. Analysis of different water withdrawal and wastewater production reveals an increasing trend across developing countries. However, the treatment and reuse rate is very shady due to the unavailability of consistent data. There is an urgent need for developing countries to double their efforts to match production with treatment and reuse.

Polysulfone (PS) and poly(sodium 4-styrenesulfonate) (PSSNa) were blended to obtain materials of various compositions. The blends were used to prepare ultrafiltration membranes by the classical phase-inversion method. The polysulfone-based membranes were employed in a magnetic stirred cell operating in a batch mode, and a selection is done on the basis of rejection, flux and resistance to fouling to find the best one to be used to concentrate polysaccharides solutions and act as synthetical textile sizing agents. This presentation reported: (a) the preparation of polysulfone-based membranes labelled PS-S1 and PS-S3, according to their PS and PSSNa composition, (b) the characterisation of the membranes by means of FTIR, DSC and TGA, which allowed to verify the blends formation and to determine glass transition temperature and initial degradation temperature of the two blends, (c) the ultrafiltration of aqueous solutions of carboxymethylcellulose and soluble starch, which allowed to proceed to the hydrodynamic characterisation of the membranes and (d) the investigation of the removal of the polysaccharides thanks to the analysis of the permeates by means of the Dubois colorimetric method, which allowed to verify the efficiency of PS-S1 and PS-S3 for this purpose.

To develop easy-to-implement and low-energy water treatment plants, pilot trials for groundwater desalination and arsenic removal were carried out at the Mekong Delta in Vietnam. Desalination was conducted by membrane capacitive deionization (MCDI), which can show low specific energy consumption (SEC) compared to other desalination technologies. Anoxic groundwater with elevated As(III) and dissolved iron (Fe(II)) was treated using a pre-oxidation/adsorption step called subsurface arsenic removal (SAR). The main advantage of the in situ SAR process is that no As-laden waste is produced. The two different qualities of the treated water from two different stages of the pilot plant can be used for various purposes and can be modularly adjusted in volume according to requirements. The pilot plant was operated using a solar PV system and a small wind turbine. Results show that SAR can reduce the As- and the Fe-concentration to below drinking water limits. The MCDI lowers the total dissolved solids (TDSs) concentration of 1560–188 mg/L. The overall process (well pump to product tap) needs an SEC = 3.97 kWh/m3, which is supplied (127%) by renewable energy.

Solar-assisted thin film evaporation is a promising step toward achieving renewable-energy powered desalination. Electrospun nanofiber membranes (ENMs) have high porosity, surface area, mechanical strength, and tunable nanofiber structure, which make them suitable for membrane desalination. In this work, electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membranes loaded with tungsten oxide (WO3) nanoparticles were fabricated and tested for solar-driven interfacial water evaporation. The ENMs, composed of three layers, and the WO3 nanoparticles were incorporated on the top layer via blending in order to maximize their surface exposure. These layers were then heat-pressed for dimensional stability. Detailed characterizations were performed applying goniometric, microscopic, gravimetric, and spectroscopic methods, and evaporation performance was tested in a laboratory-scale setup comprising a solar simulator. All ENMs exhibited a randomly oriented, smooth microporous structure, and EDS mapping confirmed the uniform distribution of WO3 nanoparticles on the surface. All ENMs were hydrophobic and have high (>20 Psi) liquid entry pressure values, indicating their potential application in membrane distillation. Furthermore, blended ENMs (P1W−P8W) exhibited enhanced mechanical strength, improved UV/Vis absorption, and have a thickness similar to that of pristine ENM. Finally, the photothermal evaporation using deionised water illustrated the enhanced performance of blended ENMs. These findings will advance the photothermal desalination processes, which can minimize the temperature polarization and improve the energy efficiency of conventional membrane distillation.

Resource recovery from wastewater treatment plants (WWTPs) has gained considerable popularity due to a worldwide shortage of carbon and energy resources. Short-chain volatile fatty acids (VFAs) are sustainable bioproducts with a wide range of applications, including a preferred substrate for bacteria involved in biological nutrient removal (BNR) wastewater treatment systems. This study applies acid-phase anaerobic digestion to produce VFAs from the primary sludge of the largest Italian WWTP at Castiglione Torinese. Acidogenic fermentation of primary sludge was performed in the pilot semi-continuous anaerobic reactor fed with the hydraulic retention time of 2 days at 45 °C. The digestate produced in the fermentative process was further characterized by the combination of physicochemical laboratory tests as well as the series of bioassay (respirometry) tests. The process simulation model, which was developed and calibrated based on extensive sampling and measuring campaigns, was used to investigate the impact of the resource recovery strategy on the plant's operation. Several operational scenarios were simulated by considering combinations of solid retention times and digestate flow rates. It was found that the optimum denitrification rate in anoxic units can be achieved under SRT >18 days when the digestate flow rate ranges between 100 and 160 m3/d.

The anaerobic sludge produced in the reactors is theoretically stabilized, but in real-scale installations, it can be observed that this sludge still contains high concentrations of cell material and also an organic matter that has not been degraded. Some pretreatment alternatives, such as thermal (heating), promote the solubilization of the sludge, increasing its potential for anaerobic biodegradation. Therefore, this study aims to investigate the maximum methane yield of thermally pretreated anaerobic sludge at (i) different temperatures (55 and 95 ºC), substrate/inoculum (S/I) ratios (0.5 and 2.0, on VS basis), and duration time of pretreatment (6 and 48 h), in the first trial, and (ii) higher S/I ratios (4.0, 6.0, and 8.0, on VS basis), at 95 ºC and 48 h pretreatment time, in the second trial. A S/I ratio higher than 2.0 and a temperature of 95 ºC were more efficient in the methane production in a short time (599 ± 55 mgCH4-COD L−1 gVS−1 d−1) in the first trial. On the other hand, in the second trial, the optimum specific methanogenic activity (992 ± 252 mgCH4-COD L−1 gVS−1 d−1) and methane yield (619 ± 95 mLCH4 gVS−1) were found at a S/I ratio of 6.0. Thus, the feasibility of producing considerable amounts of methane from pretreated anaerobic sludge was confirmed in this study, which could also be an alternative for the post-treatment of anaerobic sludge.

This research aims to test a Managed Aquifer Recharge (MAR) technique based on Forested Infiltration Areas (FIAs) to reduce the groundwater nitrate contamination of a sandy phreatic aquifer in the Arborea NVZ (Sardinia, Italy). The FIA system in Arborea will be supplied with drainage water having an average NO3 concentration of 70 mg L−1, pumped from a dewatering pumping station. The water will be treated before infiltration through an innovative passive treatment system, consisting of a mixture of inert and organic materials, to attenuate organic and inorganic contamination and to prevent clogging processes at the infiltrating surface. The experiment will be conducted for a duration of two years. Monthly monitoring will define, ante operam, the quality baseline of drainage water and groundwater and will assess, post operam, the efficiency of the FIA system. An estimation of the infiltration rate in the sandy soils based on preliminary surveys showed a potential recharge rate of around 0.7 hm3 year−1 per 0.4 ha of the FIA system.

Aquaponic systems synergistically combine the processes for the breeding of aquatic fauna with the cultivation of plants in the absence of soil, i.e. aquaculture and hydroponics. Although aquaculture and hydroponics separately are well-known worldwide and consolidated systems, there is still limited diffusion of the technology that involves their advanced combination as hybrid technology. Their combination offers several positive impacts on the circular bioeconomy. The exploitation of fish by-products as a source of nutrients for plants can contribute to the reduction of the use of anthropic fertilizers. On the other hand, the aquaponic approach can contribute to the reduction of the overall amount of water necessary for both aquaculture and hydroponics. This article reports an overview of hydroponics, aquaculture and an aquaponic system and the several challenges that are still open in the development of these systems. Further research is necessary for the development of strategies effective to increase the degree of recycling of the water, for the control of the odours and the emissions of CO2, as well as for the control of the growth of undesired algae. In addition, the combination of aquaponic systems with techniques of purification and disinfection of the water, such as membrane filtration and the treatment with ozone and/or UV radiation, will improve the quantity of the nutrients conveyed to the plants and will reduce the presence of possible pathogens and other contaminants.

The present study focused on the Mio-Plio-Quaternary tablecloth in the Oued Righ valley. This region of the lower Algerian Sahara extends from the south of the El Goug palm grove to the chott Merouane, between the wilayas of El Oued and Ouargla. The Mio-Plio-Quaternary aquifer is an important resource for irrigation and drinking water supply in the valley. In order to determine the hydrodynamic characteristics of the Mio-Plio-Quaternary aquifer and its relationship with the surface waters of the chott Merouane in Algeria, it seemed necessary to present scenarios, based on a mathematical model, using the “Visual Mod-flow” code. The calibration of the model, in a steady-state and then transient state, allowed checking the reliability of the results related to the geometry and the limits of the aquifer, as well as its hydrodynamic parameters. The exploitation scenarios indicate that the northern part, near chott Merouane, has a fairly significant vulnerability. To prevent any contact between the groundwater of the Mio-Pliocene-Quaternary and the wastewater discharged into the Chott, drastic measures must be taken, hence, the need for establishing a hydro-agricultural development plan and a wastewater management strategy.

Riparian areas provide many unique ecosystem services. These have been intensively utilized leading to the consequent ecosystem degradation. With the expected increase in population and congregation of people in urban centers, urbanization is a major threat. The alteration of the hydrologic cycle due to climate change is also expected to firstly impact semiaquatic ecosystems. This study focuses on the urban stream and torrent reaches of the city of Drama in Greece. The hydrological, geomorphological, and vegetative conditions of the selected reaches were assessed. Specifically, for the hydrological conditions, weekly streamflow measurements were taken. In addition, field water quality measurements and grab water samples were taken bimonthly. For the geomorphological and vegetative conditions of the riparian areas, two complementary visual protocols were utilized: the Ecological Quality of Riparian Habitat and the Stream Visual Assessment Protocol. The results of the protocols identified that most reaches are in poor conditions in regard to their ecological integrity. Stream water seems to be polluted from various urban sources while the presence of garbage was very frequent in the streams and riparian areas. These results indicate that more sustainable management plans and actions need to be implemented in the urban streams and riparian areas of Drama City. The city needs to implement integrated water resources principles, ecosystem-based approaches, ecotourism practices, and nature-based solutions to maintain and improve the quality of its streams and riparian areas.

This study was designed to evaluate the effects of different percentages of phosphogypsum (PG) on the physical properties and erodibility in sandy soil of south Tunisia. Our results show that the physical properties of sandy soil were greatly improved with the addition of different percentages of phosphogypsum which strengthened the water holding capacity, and higher particulate matter content. Also, the PG amendment reduced the erodibility of the soil compared to the original sandy soil. The erodibility K values achieve 1.44% in 40% PG compared to 0.10% in untreated soil (U). In conclusion, our results demonstrate that different percentages of PG are effective to improve the quality of the sandy soil, including the improvements of the soil structure, nutrients, and anti-erosion ability. Our findings provide important implications for the soil improvement in the farmland of South Tunisia.

Volatile organic compounds (VOCs) laden emissions are becoming of great concern in the context of atmospheric pollution, due to their adverse effects on both the environment and human health. Physical–chemical processes (PCPs) and biological processes (BPs) represent widely used solutions for the VOCs degradation. The process limitation by recalcitrant nature and toxicity of the secondary metabolites for BPs and the need for further treatments of the phase in which the contaminants are transferred for PCPs represent critical aspects for the implementation of the conventional processes. To overcome these drawbacks, the development of innovative advanced oxidation processes (AOPs) for the treatment of gaseous organic compounds is of key interest. The research aims at evaluating the performances of UV-assisted ozonation (UV/O3) process for the degradation of VOCs emissions. Toluene was identified as the target compound for the experimental activities. A novel configuration with an additional scrubbing phase is proposed and assessed to improve the removal efficiency and to prevent the release of polluting intermediates of the single-step process. Inlet toluene concentration and applied voltage were varied in order to test the investigated configurations. As inlet concentration was increased, abatement of toluene decreased. An increase in ozone concentration led to an increase in the degradation efficiencies. The additional water-scrubbing step enhanced the abatement of UV/O3 up to 98.5%, due to the solubilization of ozone and by-products in the process water and, thus, the further oxidation of the contaminants within this phase. A maximum elimination capacity (ECmax) of 22.6 g m−3 h−1 was achieved with the UV/O3 + Scrubbing. The combined system boosted higher performance and stability compared to the stand-alone (UV/O3) process along with more economical and environmental sustainability.

The study has investigated the use of an Algae-Sludge Membrane Bioreactor (AS-MBR) for wastewater treatment. Its performance, in terms of pollutant removal and membrane fouling mitigation, was compared to that of a previously reported conventional MBR. Results showed that it has a COD removal efficiency that is only slightly higher than that in the conventional Membrane Bioreactor (MBR). The effect of the combined microalgae (Chlorella vulgaris) and activated sludge biomass resulted in more efficient nutrient removals in the AS-MBR than in the conventional MBR. Higher removals of NH4+-N and PO43−-P by 43.89 and 6.4% were observed in the AS-MBR. However, detection of NO3−-N at the effluent revealed that denitrification was not a dominant nitrogen removal pathway in the system. Membrane fouling mitigation in the AS-MBR was observed through the lower membrane fouling rate and lower concentrations of Extracellular Polymeric Substances (EPS) and Soluble Microbial Products (SMP). The decrease in membrane fouling rate and increase in Transparent Exopolymer Particles (TEP) concentrations in the mixed liquor of the AS-MBR compared to the conventional MBR also showed that these are not the dominant fouling substances in the system.

Wastewater treatment plants (WWTPs) provide a potentially conducive environment for bacterial antibiotic resistance development since bacteria in the mixed liquor are in constant contact with sub-inhibitory antibiotics concentrations. Several studies have reported the survival of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARG) during the wastewater treatment steps. Among the ARBs, the carbapenem-resistant Klebsiella pneumoniae ranked as a priority 1 (critical) pathogen by The World Health Organization (WHO) constitutes a major threat to public health. Therefore, this study aimed to investigate nonthermal plasma (NTP) technology as an alternative disinfection method and its effect on ARG. A culture-based method and polymerase chain reaction (PCR) were employed in confirming the carbapenem resistance gene blaNDM-1 in Klebsiella pneumoniae (ATCC BAA 2146). A suspension of carbapenem-resistant K. pneumoniae (16 h culture) at OD625 was prepared from the confirmed isolate and was subjected to plasma treatment at varying time intervals (2, 4, 8, and 12 min) in triplicates. The plasma-treated samples were evaluated for re-growth and the presence of the resistance gene. After the plasma treatment, the blaNDM-1 gene could only be detected in the 2 and 4 min treatments. The treatment resulted in a 0.6 log reduction after two minutes, while the highest log reduction of 1.3 was achieved after 12 min of treatment. These results suggest that plasma disinfection has great potential to be an efficient tertiary treatment for wastewater. However, the technology is still young, and there are many factors that still need to be optimized before implementation is possible.

Surface water body maps are necessary input for effective and targeted mosquito larviciding actions, assisting in the prevention of outbreaks due to viruses transmitted to humans by mosquito carriers, such as the West Nile Virus. The aim of this study is to identify the optimum automated method for monitoring water bodies in rice fields and wetlands, capitalizing on the Sentinel-1 satellite mission. The methods tested were assessed against field data collected in northern Greece. The comparison of various methods showed that the Otsu Valley-emphasis thresholding image binarization technique is the one which provides the highest accuracy. At the end of the rice-growing season, the lower overall accuracy was due to the higher density of vegetation. The presence of vegetation, built-up areas, floating algae, salt-crust formations, and water depth are causes of water detection errors. The fully automated water monitoring tool and the associated water maps are intended to be used as input to the DSS of project WaMoS, together with other parameters affecting larvae presence, in order to improve the environmental sustainability and effectiveness of larvicide applications.

Pharmaceutical compounds such as antibiotics are considered to be emerging environmental contaminants due to their continuous discharge into and persistence in the aquatic ecosystem. The removal of a widely used antibiotic amoxicillin by adsorption onto activated carbon was studied. Experiments were performed in static mode and the influence of several parameters was investigated. The results showed that the adsorption was rapid and kinetics were well fitted with the Elovich model. The relative experimental adsorption isotherm was in accordance with the Sips model. The adsorption capacity increased with the antibiotic initial concentration and was influenced by the solution’s pH and ionic strength. The thermodynamic study showed that the adsorption was spontaneous, endothermic, and chemical in nature.

Located in the South of Tunisia, the mounts of Matmata, face a rarity and large irregularity of water resources. This scarcity has driven the local population to invent techniques like “Mejel” and “Fesguia” to store rainwater in order to cover the needs over a longer period of time. The traditional rainwater harvesting techniques in the Matmata Mountains are essentially characterized by their key role in the storage of runoff water, which represents a significant renewable water potential despite the scarcity of rainfall. Serious attempts to exploit the runoff water for human consumption and rainfed agriculture and reduce the water erosion in the mountain regions. This study aims to examine the rainwater stored in collection tanks (called “Mejel” and “Fesguia”) based on chemical analysis of 327 samples of water, carried out in the Laboratory of Eremology and Combating Desertification at the Arid Regions Institute (ARI) Medenine-Tunisia. The results build an idea about the quality of water tanks intended for human consumption. In fact, the physico-chemical analysis of water in tanks showed an acceptable chemical composition that meets the standard suggested by the WHO except for a few samples. However, the microbiological analysis has shown that 60% of the collected samples have a quality that does not comply with the standards, which is why a disinfection operation is mandatory to prevent or at least minimize any kind of microbial contamination.

Climate change demands for sustainable options for heating and cooling of buildings. Low-temperature thermal energy can be abstracted from the drinking water distribution system (DWDS); this is called thermal energy from drinking water (TED). The possible use of TED as a secondary function of the DWDS raises the question whether this secondary function can exist alongside the primary function (supplying safe and reliable drinking water) and, if so, under what conditions. Using various cases, the potential downstream effects of TED related to drinking water temperature (and hence, downstream increase of cost and CO2emissions for water heating) and microbiological drinking water quality were studied.

The energy demand of a pilot greenhouse for rose cultivation at Al-Quds University/East Jerusalem is calculated. Local meteorological data were used to estimate energy demand for cooling and heating. Due to high energy consumption for heating, it is recommended to heat only if the temperature drops below 15 °C as this threshold is still considered within an acceptable temperature range and consumes a third of the energy (26,691 kWh per year) compared to maintaining the optimum temperature for crops all year. For this scenario, 49 solar panels with a total investment cost of 14,700 US$ are needed. Cooling does not require a lot of energy and is recommended to protect flowers from heat-related damage and diseases.

In order to improve the irrigation efficiency of the photovoltaic greenhouse, better understanding and quantifying the sensible and latent heat exchanges at the plant level could be helpful. In this context, the aim of this work was to develop a numerical model to simulate the evolution of transpiration and microclimate inside the greenhouse under day-time conditions, where the influence of solar radiation is predominant. These models were integrated inside a CFD model (computational fluid dynamics).

The Kingdom of Saudi Arabia (KSA) is almost completely dependent on fossil fuel to satisfy its energy demand of all its economic sectors. The KSA vision of 2030 calls for the diversification of energy sources in the Kingdom. Accordingly, the KSA has launched a promising plan that aims to gradually power the major industrial activities in the country by renewable and low-carbon energy sources. The geothermal sources are among the promising renewable sources that can support the achievement of the country vision and energy mix plan. Saudi Arabia is rich with several geothermal resources especially in the western and southwestern regions along the Red Sea area. The potential of the basaltic fields, called Harrat, that covers more than 80,000 km2 in the west of the Arabian shield is considered a sizeable opportunity for producing geothermal power. Harrats are considered high-enthalpy resources that could be used for power generation if a comprehensive geothermal resource assessment was achieved. Moreover, the north and northwestern parts of the Arabian shield are rich in high-generating granite which is a type of hot dry rocks with a huge reserve of stored energy. These granites are estimated to yield a heat production in the range of 15–134 μW/m3. This paper provided an overview of the status of geothermal energy in the world and document international key challenges for resources development. The paper introduced the potential geothermal resources in the KSA and highlighted the key barrier toward its full utilizations. Finally, the study recommended the development of pilot projects for geothermal energy generations at the high-technical potential areas. These pilot projects will contribute to a full assessment of geothermal energy feasibility in the kingdom and facilitate private sector investment in geothermal energy production.

Twenty (20) shallow wells were sampled during the dry season (October 2015) from the Guenniche plain (Northern Tunisia) and examined for their suitability for irrigation. The physicochemical analysis results are used to estimate 10 indexes: the sodium absorption ratio (SAR), percentage of sodium (Na %), residual sodium carbonate (RSC), permeability index (PI), magnesium ratio (MR), residual sodium bicarbonate (SBC), salinity hazard (SH), potential salinity (PS), soluble sodium percentage (SSP), and Kelley’s Ratio (KR). The majority of the criteria (SAR, %Na, RSC, PI, KR, and RSBC) indicate that 100% of the studied water is ‘permissible’ for irrigation. But the rest of criteria show different results. The PS results classify 90% of the samples into the “moderate to satisfactory” category due to high chloride (Cl−) values (average Cl− value 589 mg.l−1) and SH index shows that 65% of groundwater samples are falling in the ‘doubtful’ category. The use of the IDW method for the spatial distribution of the criteria points out that central area and East of Guenniche plain are characterized by the low groundwater quality for irrigation purposes. The improvement of the efficiency of irrigation fertilization in those areas’ practices would improve the water quality of the Guenniche shallow aquifer.

The assessment of groundwater abstraction is an important tool to ensure its sustainability and management. This study aims to assess the groundwater abstraction for irrigation during the hydrological year of 2016–2017, using GIS, and to compare it with the water abstraction estimated by the Tunisian water management authority. This land use map allowed us to extract the different irrigated crops and to calculate the irrigation water requirements (IWR). The results showed that the groundwater pumping volume is approximately 34.29 Mm3. This volume is 2.7 times higher than the one published by the Tunisian water management authority, which is equal to 12.7 Mm3. This significant difference (21.59 Mm3) is caused by the increasing number of illegal wells (digging wells without a permit from the water management authorities).

In this work, several configurations of seawater desalination plant by vacuum membrane distillation were presented. Two types of membranes were studied: flat membranes and hollow fiber modules. These systems use solar energy to supply the heating needs for the seawater to be desalinated. The different possibilities depend on the type of collector used (plan collector (CP), cylindro-parabolic solar collector (CPC), or solar pond (SGSP)) and the nature of the coupling of the module with the collector (integrated or separate module). The type of flow within the fibers (external–internal or internal–external) is a key parameter for the design of these configurations. The performance analysis of the different possible configurations made it possible to compare their productivity according to the type of collector used and to study quantitatively the interest of integrating a hollow fiber module within the solar collector. The study of different configurations made it possible to present the advantages and disadvantages of each configuration. This work made it possible to evaluate the annual production of desalted water by the vacuum membrane distillation; this production varies from 5 to 32.5 m3/m2.

Fossil fuels represent the primary energy sources, amounting to an 85% share of the total energy used in the world. The burning of fossil fuels caused the increase of greenhouse gas emissions (GHGs) in atmosphere resulting in global warming. Development of smart and cost-effective technologies for carbon capture and biomass production are among the suggested solutions for the mitigation of GHGs emissions and the generation of alternative and renewable energy carriers. Several biotechnologies are present in the scientific literature and in the commercial market for CO2 capture and utilization (CCU) (e.g., open and closed photobioreactors). High energy demand processes are generally used to harvest microalgal biomass (e.g., membrane filtration, gravity sedimentation, centrifugation) to produce valuable products (e.g., food, fertilizer, and biofuels). Therefore, advances in scientific research with the aim of reducing energy consumption and making the process completely sustainable are required. This research presents and discusses an innovative biotechnology system, patented by the Sanitary Environmental Engineering Division (SEED) research group of the University of Salerno, for carbon capture and utilization. The energy consumption of the advanced membrane photobioreactor (seed-mPBR) is highlighted. A comparative analysis of the proposed seed-mPBR and conventional tubular photobioreactors is pointed out and argued. The aim of the research is providing useful information on energy consumption reduction in biomass harvesting process, as well as promoting the development of more sustainable CCU systems. The result highlights a lower energy consumption of the proposed seed-mPBR system in comparison with tubular photobioreactor that integrates flocculants. By improving the efficiency of the SFDM, a fivefold reduction of the energy demand could be achieved.

The success of biogas technology to produce methane is also affected by cattle feed. This study aimed to investigate the effect of feeds on methane production. Three types of these feed treatments were as follows: low-energy feed, high-energy diet, and restricted high-energy diet. Every 10 days until 40 days of the fermentation process, methane contents in biogas were measured. The results showed that biogas produced from cattle manure was affected by feed treatment. Different types of feed significantly affected on the level of biogas volume. The results also showed that after 40 days of anaerobic digestion, the highest methane production was obtained from cattle fed with low energy feed. From this study, we concluded that the biogas upgrading can be achieved by giving low-energy feed treatment.

The fruit and vegetable sector generates large amounts of waste. This organic waste is mainly generated before consumption during agricultural production and distribution. In Tunisia, fruit and vegetable waste (FVW) started creating enormous waste disposal problems due to the negative effects of improper waste management. The disposal of these wastes in a municipal landfill site represents a loss of valuable biomass and also affects the overall economy of the country. Considering the high moisture and organic content of FVW, the anaerobic digestion can be an attractive option for energy generation as well as for reducing the disposal problem. In this context, the aim of this work was to study the anaerobic co-digestion of FVW and poultry manure. The objectives were to characterize substrates by chemical-fluorescence fractionation method, investigate the performance of FVW co-digestion in a hybrid solid batch bioreactor, and evaluate the fertilization characteristics of digestate. The determination of the methane potential of substrates during mono- and co-digestion tests showed a correlation between the biogas yield and the bio-accessibility as well as the complexity index of organic matter present in FVW. The co-digestion experiment conducted in a bi-phasic reactor with leachate recirculation showed the stability of anaerobic bio-systems and an improvement of biogas yield of (22.5%). The physicochemical characterization and the phytotoxicity test indicated the fertilizing quality of obtained digestate.

This work aims to valorize food waste available in the Umbria region (Italy). According to the anaerobic digestion, the resulting biogas production can be divided into two periods. In the first one, 22 L of a mixture were digested during the initial test days without daily charge, and in the second period, the daily mixture was inputted ensuing a determined organic loading rate equal to 1.5 g VS/L/day. Globally, the results indicated that biogas production has started since the first test day and has increased steadily in the first two days until it reaches its peak on the 2nd day before declining. The cumulative biogas volume produced within the 41 days of the experimentation test was 0.269 Nm3/Kg VS. As a result, bio-methane percentages from the total biogas volume were, respectively, 66.67% and 56.22% during the first and second periods. The anaerobic digestion of this mixture has shown higher alkalinity to resist against the acidity pH of the food waste.

Volatile organic compounds’ (VOCs) emissions in the atmosphere are among the gases that can affect the health of the exposed population and can be harmful to the environment. One possible solution to control the VOCs’ emissions is the application of algal-based technology like photobioreactor (PBR). In this paper, advanced algal–bacterial PBR was assessed and evaluated in terms of the degradation of toluene. Chlorophyll content and total suspended solids (TSS) were also measured to analyze the potential of the investigated technology as a source of biomass production for energy. The results showed high toluene removal efficiency, ranging from 87.42% to 99.74%. Correspondingly, TSS and chlorophyll contents increasing, from 560 mg/L to 760 mg/L and from 1.21 mg/L to 4.06 mg/L, respectively, was observed. The high removal efficiency of toluene and concentration of biomass produced from the proposed biological-based technology, proving its sustainability for the control of VOC emissions and production of alternative energy.

In this paper, we report current problematic issues of environment—health interactions in the context of phosphogypsum storage. Tunisia suffers from pollution problem mainly from the Tunisian Chemical Group. Phosphogypsum is the by-product of the manufacture of phosphoric acid, resulting from the sulfuric attack of a natural calcium phosphate ore. On the environmental front, crude phosphogypsum is likely to release heavy metals and radio-elements into the water and into the atmosphere, which poses serious problems. Several researchers have shown that a variety of materials of natural or biological origin are characterized by their ability to fix significant amounts of heavy metals, taking the example of clays that have been the subject of various studies for various applications such as adsorption. Chemical analysis of phosphogypsum waste indicated a high concentration of heavy metals, particularly Cd and Cr. On the other hand, radioactivity study indicated that the Ur and Th levels were acceptable and not dangerous to human health. Column experiments with clay give positive and encouraging results, as the Haidoudi and Romana clay deposits showed the capacity to absorb the extractable metals in the phosphogypsum waste. The natural clays from Gabes area, Tunisia, turned out to be an effective natural adsorbent for capturing metals from phosphogypsum waste and can be effectively used for the treatment of contaminated wastewaters in the environment.

This paper deals with the use of biodiesel in internal combustion engines. Biodiesel is obtained from used frying oil. The characterization of biodiesel, as well as its blends formulated with diesel (B100, B75, B50, and B25), is reported. To do this, three aspects have been covered: (i) characterization of biodiesel and its blends by the study of their density, low heat value, and viscosity in comparison with fossil diesel fuel; (ii) test of an internal combustion engine taking in account parameters such as mass flow, effective specific consumption, combustion efficiency, exhaust gas temperature, etc., and (iii) exhaust gas analysis assessing carbon monoxide, hydrocarbons, nitrogen oxides, and combustion efficiency through an attempt to model the process. The tests were carried out using a bunch of tests on a single cylinder diesel engine to study its performance, emissions, and combustion of biodiesel and its blends. The results show an increase of 3–9% for effective specific consumption, and a 5–9% decrease in engine efficiency. In terms of emissions, there has been a decrease in carbon monoxide (30–78%) and hydrocarbons (52%), and with regard to nitrogen oxides, an increase of 15%. This sector may become economically interesting. But in Morocco, the marketing of biodiesel is not yet authorized. Only self-production for self-consumption is possible.

The UK is a global leader in the decarbonisation of its electricity grid to meet zero-carbon targets. However, the main renewable sources, wind, and solar are intermittent and weather dependent. Therefore, other flexible sources need to be able to rapidly increase generation when needed. In this context, electricity generation from anaerobic digestion (AD) of sewage sludge has been traditionally operated as a baseload provider (i.e. steady biogas production rate and electrical output). This work challenges such a traditional approach and aims to investigate how the sewage sludge-to-electricity generation system can provide flexible renewable power generation. Specific feeding regimes were designed following an analysis of the power grid balancing services, to increase the biogas production rate when needed. These feeding regimes were tested at incremental experimental scales. Multiple AD conditions were tested at a pilot scale (50 l) in a controlled environment, which proved the potential economic and environmental benefits. Then, the most challenging conditions were tested at a demonstration scale (18 m3), which confirmed the results obtained at the pilot scale in a relevant operational environment. This research work proved that by implementing an appropriate control of AD, the process can produce more biogas in peak periods to generate electricity when the grid’s prices and carbon emissions peak, unlocking the potential for full-scale implementation.

Recirculation of the reject water (RW) from sludge treatment units can cause significant load fluctuations in the biological nutrient removal activated sludge (BNRAS) systems at wastewater treatment plants (WWTP). Because the characteristics of these influent sources are highly variable, optimizing the operation of a WWTP under high-load conditions is a challenging task. This study describes an application of model-based scenario analysis to investigate the impact of various operating conditions on the performance of a BNRAS at the largest Italian WWTP. The process model was developed and calibrated based on the sampling and measuring campaigns. Before real-scale implementation of the side-stream DEMON® Anammox treatment technology, a feasibility analysis was carried out by developing fictional scenarios. Results show that the reduction of nitrogen load by the side-stream implementation of the DEMON® process could provide an opportunity to optimize the performance of BNRAS based on Solid Retention Time (SRT). By integrating the side-stream treatment of RW with SRT optimization in the BNRAS units, energy consumption can be reduced by up to 20%, and the effluent quality can be improved.

Reliable performance evaluation of wastewater treatment plants (WWTPs) demands accurate wastewater characterization. Wet weather events alter influent wastewater flow and loadings, lowering the treatment efficiency and increasing operating cost as well as the risk of effluent violation. Although it is generally accepted that wastewater characteristics vary in wet weather events, variations of COD fractions during rain and storm conditions have been insufficiently considered. In this study, sampling and measuring campaigns were performed during various wet weather events at the largest Italian WWTP. The samples were analyzed by two fractionation methods based on physicochemical and respirometric techniques. The impact of low load conditions due to the dilution of the samples on respirometric assays was investigated. A comparative analysis of the COD fractions confirmed that significant divergence might exist between two fractionation methods. Eventually, a proper technique is proposed to characterize biodegradable organic matter of influent municipal wastewater during rain and storm events.

This research proposes a comparative analysis of the criteria for the construction and installation of plumbing and wastewater evacuation systems in residential buildings. Facility regulations tend to differ depending on the country in which they are enacted. These regulatory differences should not exist since the same rights must be enjoyed regardless of the place where the property is located. For this, the applicable regulations in force in Italy, Spain, and Europe have been taken as a reference. These standards have been analyzed to understand the different uses of the relative countries, but also the motivations that stimulate a design in a specific direction. It has been concluded that the water supply installation is more efficient according to the Spanish regulations, and the water evacuation installation is way more optimal with the union of both regulations. The European Union provides a broader legal framework, and Member States follow these guidelines according to their specific context.

Controlling energy is one of the most important challenges facing humanity. In fact, the building sector accounts for a significant portion of global energy consumption. In this regard, thermal insulators, which are part of building materials, are steadily gaining in importance as means of saving energy. This paper aims to present new cement-based materials, thermally reinforced with different materials, developed for thermal insulation. Experimental measurements of the thermal properties of new composite materials were carried out using the hot disk method in order to deduce the real impact of these materials on the thermal comfort of buildings. The results showed that the thermal conductivity of cement paste decreased with an increase in the percentage of reinforcing material.

The water and soil salinization, economic and vital importance of water, and nutritional value of nitrogen fertilization make it expedient to establish this work which investigated the interaction between nitrogen fertilization and saline water irrigation. The experiment was undertaken in an arid region to compare the performance of four contrasting barley genotypes and select the most efficient one that can be irrigated by brackish water. Barley genotypes were irrigated with two water salinity levels (1.8 and 9.2 dS/m), and four N fertilizer levels were applied (0, 50, 100,150 KgN/ha). Results highlighted the corrective effect of nitrogen on saline water. Data showed a significant reduction (P < 0.05)—caused by saline water—in the number of fertile tillers (38%) and leaves (10%), chlorophyll content (10%), and biomass production (12%); leading to a decrease in grain yield by 6.3 Qx/ha. These reductions were observed in all genotypes with variable rates. On the other hand, nitrogen application showed a significant increase (P < 0.05) in the number of fertile tillers (28%) and leaves (5%), chlorophyll content (8,3%), and biomass production (NDVI value) by 40%. Data showed that the improvements caused by N addition were more evident under salt stress. Our results showed that the inhibitory action of saline water has been significantly reduced by nitrogen fertilization. This makes it possible to predict the corrective effect of nitrogen on the vegetative development and grain yield under saline conditions with an adjusted nitrogen level.

The Tunisian country, as an emerging economy, is increasingly in severe concern with the environmental challenges. In particular, the post-revolution period is characterized by an accelerated unplanned urbanism rate leading to rapid domestic waste increase versus a poor waste governance. Obstructed by the absence of relevant data, we carried our surveys using LCA approaches to qualitatively scrutinize the weakness of the existing MSWM system and its impacts on the life quality, mainly on the water quality, and how it is the factor of water drainage besides the climate change effects. Using the causal effect loop, we grasped the main factors consisting on the poor data production system, the tight social mental system, and the absence of strategic management schedule to be the root cause of the sharp decrease of the water-soil-air quality all along the country. As a first step, we tested the realization of a normal scale smart bin that may match the local context needs and may serve as an efficient tool for better accurate and real-time data monitoring of waste generation.

Tunisian oases are experiencing an extension in area and an increased and gradual mobilization of irrigation water. Currently, these oases are supplied mainly from the waters of two fossil aquifers: the aquifer of the terminal complex (CT) located between 60 and 500 m deep and that of the intermediate complex (CI) located more than 2000 m deep. These oases are generally located on the edge of chotts, salty topographic depressions which constitute the natural outlet for drainage water. However, in many cases, the slight elevation differences between the oases and the chotts plus the sandy amendment operation cause difficulties for the evacuation of water. Consequently, a majority of these oases are subject to problems of rising groundwater and soil salinization, accentuated by inefficient management of irrigation water and drainage and soil. The combination of these factors hinders good hydrosaline functioning by accentuating the signs of hydromorphy and further weakening the balance of the oasis system. The study of the effects of the amendments applied on the water characteristics of the soil was carried out in two oases in the region on amended plots and unamended plots. The results obtained showed that the sandy amendment of oasis soils increases their permeabilities and decreases their reserves of usable water. In terms of irrigation, the doses to be applied are less important in amended soils and the irrigation periods are shorter than for unamended soils. In addition, it should be noted that the irrigation doses, the irrigation periods, the leaching fractions calculated for amended and unamended soils are much lower and those actually applied by farmers. This results in excessive water losses during irrigation leading to the continuous rise of the water table which today poses a real problem for the oases of the region. Also, the turn of water practiced in these oases and which exceeds 20 days leads to the water stress of the cultures practiced in particular the herbaceous crops.

Minimizing energy consumption has become a hot topic over the last year regarding the limitation of fossil fuel resources. However, cooling systems are among the most energy-consuming devices. The stimulation of technological innovation increased pressure on manufacturers to design new control techniques to improve the operation of cooling systems, while optimizing costs. For this purpose, two control techniques are proposed and used to regulate the air temperature inside the cooling system. The first technique is the predictive controller and the second is the PID regulator. The mean objective of the controllers is to minimize energy consumption while guaranteeing the desired level of internal temperature. The simulation results showed that the predictive control allowed the output temperature to reach the set point faster than the PID controller thanks to the anticipation effect.

The growing of olive trees in Palestine was an important pillar of the Palestinian economy. Rainfall fluctuation and shifting in winter season to early spring (April) cause a decrease in yield, which makes this sector not attractive from an economical point of view. This paper focuses on the evaluation of the supplementary irrigation practices from the cost–benefit analysis point of view and the possibility of using this practice in improving the income of small farmers. A comprehensive survey and semi-structured interview with a population sample of 40 farmers were conducted. Used SPSS and feasibility analysis method were applied. Supplementary irrigation with fresh as well as with treated wastewater was applied during the period from June to September with 3 m3/tree distributed among six irrigation schedules, to increase the yield from 5.6 to 12.5 kg of oil/tree (13 trees per donum) by an average annual rainfall of 450 mm/year. The net profit was 808$/year donum for freshwater while using treat wastewater is 704$/year donum.