Water Reuse and Environmental Sustainability

Dear Colleagues,

Due to global warming and pollution, the amount of freshwater available to humanity may not be sufficient to meet the growing demand. In fact, the world population living in less developed regions is about 84% of the total, and the proportion of the population residing in urban areas has tripled in the last century, with a significant increase in the size of megacities. It is also acknowledged that urbanization places stresses on the basic needs, including food, water, housing, sanitation, waste management, and many more. From this perspective, the value of water is increasing enough to seriously affect the global economy and geopolitical balance. Recent reflections raise fundamental questions for the environmental management of wastewaters and their reuses and represents one of the biggest challenges that society faces today on a global scale.

Wastewater reuse requires a treatment that depends on how the waters will be used. Higher-level uses, such as irrigation of agricultural areas, require a more effective treatment than lower-level uses, such as pasture irrigation. Moreover, in urban reuse, where there is a high potential for human exposure, the water must be adequately disinfected for a safe distribution.

The issues related to the reuse of waste water, in a global perspective that embraces all the open issues in the widest situations, are the subject of this Special Issue of Sustainability. Among the numerous themes, we can suggest:

• Potential and limits for the reuse of urban wastewater in the context of environmental sustainability;
• Potential for water reuse as an energy or material resource;
• The climatic and anthropogenic causes affecting water scarcity and the role that the reuse of wastewater can play in a short- and long-term perspective;
• The quantity and quality of freshwaters available, the possibility of increasing supply, and the role that reuse of purified wastewaters can play specifically in highly populated urban areas;
• The solutions planned and envisaged to increase the reuse of purified wastewaters;
• The efficiency of the reuse of purified wastewater in relation to collection networks;
• The types of pollutants and available technologies for the abatement of traditional pollutants, persistent organic pollutants, and emerging and priority micropollutants in urban wastewaters;
• The role of advanced technologies (IoT, digitalization, smart metering and devices, modeling, etc.) to promote wastewater reuse;
• The impact of wastewater reuse in the energy balance;
• Cost analysis and economic sustainability for efficient reuse;
• Methodologies for an efficient distribution of treated wastewater in agriculture;
• Wastewater reuse in agriculture and crops: effects on yield, risk of contamination, possible effects on groundwater quality, soil–wastewater interactions;
• Differences and similarities in the reuse of purified urban wastewater in agriculture and the application of sewage sludge as amendments to agricultural soils;
• Alternatives for the reuse of purified water in urban areas in the context of smart cities, with particular regard to applications of nature-based solutions;
• Scenarios for the reuse of industrial wastewater;
• The holistic (multicriteria) approach for comparing alternatives;
• Advanced tools for assessing waste water suitability for reuse (e.g., eco-toxicological approach, risk analysis);
• Conflicts, delays, and regulatory difficulties in the use of purified water;
• Impact of the regulation frame, new or upcoming regulations on water reuse.

Dr. Gianni Tartari
Prof. Dr. Giorgio Bertanza
Guest Editors

Manuscript Submission Information

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• Water sustainability
• Water reuse in a changing world
• Circular economy
• Water management
• Rules and laws for the reuse of purified water
• Emerging pollutants of concern
• Risk analysis
• Ecotoxicology
• Advanced technologies
• Multicriteria assessment
• Industrial reuse
• Agricultural reuse
• Material resources
• Energy saving and recovering