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The purpose of this paper is to investigate the principles on how to reuse the reclaimed wastewater in urban areas and furthermore, to determine appropriate reuse targets and optimize the selection of reuse targets on wastewater.

Use Analytic Hierarchy Process (AHP) to suggest the assessment criteria and subject weights of wastewater reuse. Candidate reclaimed wastewater reuse targets in this study includes “agriculture irrigation,” “industrial use,” “environmental use,” “urban use,” “groundwater recharge,” “life-use water,” and “infusion reservoir.”

The analysis results of the pairwise comparison of the water targets under different assessment criteria level show that in all water targets, agriculture irrigation is more important than industrial use under the “public acceptance” at first. Then, the order results were used to suggest the future wastewater reuse targets under different assessment criteria levels and conducted an acceptance survey on the people of the urban areas.

The results of this study can be a useful information for the system analysis of wastewater reclamation and reuse.

Urban population growth has increased pressure on natural resources, water in particular. It has resulted in serious water stresses, poor waste management and severe diffuse pollution. To achieve more favourable solutions, there is a need to look for technological alternatives based on the principles of closing cycles. Incorporation of the agricultural system to the sanitary system with nutrient recycling is one of the major ways of closing the loops in urban and peri‐urban areas. However, various partnerships with all actors of the civil society should be established. Development and implementation of successful reuse operations require more research work to define urban models in which material cycles are closed at affordable economic costs. This paper aims at discussing alternative water management approaches to ensure environmentally sound urban and peri‐urban water‐related relationships.

Rough estimations of water gain through greywater reuse and rainwater harvesting together with energy recovery from wastewater generated from a fictitious eco-city of population 100,000 located in Istanbul, Turkey form the main framework of the study. As such, the highly important concept of water–energy nexus will be emphasised and domestic wastewater will be partly considered for water recycling and the rest for energy recovery. The paper aims to discuss these issues.

Distribution of daily domestic water consumption among different household uses and the population in the residential area are the two governing parameters in the practical calculation of daily wastewater generated. Therefore, domestic wastewater will be initially estimated based on population, and in turn, the amount of greywater will be found from the per cent distribution of water use. After segregation of greywater, the energy equivalency of the rest of the wastewater, known as blackwater, will further be calculated. Besides, the long-term average precipitation data of the geographical location (Istanbul) are used in determining safe and sound rainwater harvesting. Harvesting is considered to be only from the roofs of the houses; therefore, surface area of the roofs is directly taken from an actual residential site in Turkey, housing the same population which is constructed in four stages. Similarly, the fictitious eco-city in Istanbul is assumed to be constructed in a stage-wise manner to resemble real conditions.

The water consumption of the fictitious eco-city ABC is considered as 15,000 m³/day by taking the unit water consumption 150 L/capita.day. Therefore, total water savings through on-site reuse and reuse as irrigation water (9,963 m³/day) will reduce water consumption by 64 per cent. Minimum 40 per cent water saving is shown to be possible by means of only greywater recycling and rainwater harvesting with a long-term average annual precipitation of 800 mm. The energy recovery from the rest of the wastewater after segregation of greywater is calculated as 15 MWh/day as electricity and heat that roughly correspond to electricity demand of 1,300 households each bearing four people.

A fictitious eco-city rather than an actual one located in Istanbul is considered as the pilot area in the study. So far, an eco-city with population around 100,000 in Turkey does not exist. An important implication relates to rainwater harvesting. The amount of safe water to be gained through precipitation is subject to fluctuations within years and, thus, the amount of collected rainwater will highly depend on the geographical location of such an eco-city.

The study covering rough calculations on water savings and energy recovery from domestic wastewater will act as a guide to practitioners working on efficient water management in the eco-cities, especially in those that are planned in a developing country.

Practising water–energy nexus in an eco-city of population 100,000 regarding water savings and energy recovery from wastewater forms the originality of the study. Sustainable water use and energy recovery from wastewater are among the emerging topics in environmental science and technology. However, safe and sound applications are lacking especially in the developing countries. Guiding these countries with practical calculations on both water gain and energy recovery from wastewater (blackwater) is the value of the work done. Moreover, Istanbul is deliberately selected as a case study area for various reasons: its annual rainfall represents the worlds’ average, it is one of the most crowded megacities of the world that supply water demand from the surface water reservoirs and the megacity has not yet significantly increased wastewater reuse and recycling practices.

This study provides details on the development of a qualitative approach to the assessment of public evaluation of water recycling schemes. The approach involved the presentation to a small group of information and audiovisual material on the water cycle and wastewater treatment followed by the use of focus group style questioning to elicit discussion and questioning of the material. Qualitative analysis, based on a discursive method of evaluation, was used to assess dialogue in the groups, and it was concluded that participants used the context of the local scheme to assess their use of recycled water and consider extending the application of recycled water to more personal uses. Participants also tended to use item evaluation rather than category evaluation of water recycling. Agreement responses within workshops also influenced the discourse of evaluation of water reuse.

The purpose of this paper is to apply reverse osmosis (RO) to the treatment of industrial wastewater from a large petrochemical complex in Southern Brazil, in order to verify the conditions of liquid effluent reuse and improve them, especially to reduce the consumption of natural water by some production structures such as boilers and cooling towers.

The petrochemical wastewater was submitted to pretreatment using a sand filter and activated carbon filters. Tests were conducted using RO equipment with a production capacity of 0.25 m³h⁻¹ composed of a spiral membrane module with a membrane area of 7.2 m². Pressures of 8, 12 and 15 bar were applied with reject flow maintained constant at 10 Lm⁻¹.

The experiment results indicated optimum RO performance since more than 90 percent extraction was obtained for most of the compounds present in the petrochemical wastewater.

By checking the aspects involved, as well as providing some relevant considerations about, this study promotes the application of RO to get a satisfactory water reuse in similar industries, thereby decreasing both the volume of water extracted from wellsprings and the amount of wastewater released into water bodies.

A systems perspective of waste management allows an integrated approach not only to the five basic functional elements of waste management itself (generation, reduction, collection, recycling, disposal), but to the problems arising at the interfaces with the management of energy, nature conservation, environmental protection, economic factors like unemployment and productivity, etc. This monograph separately describes present practices and the problems to be solved in each of the functional areas of waste management and at the important interfaces. Strategies for more efficient control are then proposed from a systems perspective. Systematic and objective means of solving problems become possible leading to optimal management and a positive contribution to economic development, not least through resource conservation. India is the particular context within which waste generation and management are discussed. In considering waste disposal techniques, special attention is given to sewage and radioactive wastes.

The textile industry is one of the largest and most important industrial sectors in India. Because the textile industry consumes large quantities of water and produces highly polluted water discharge, its environmental impact is high. Water is expensive to use, treat and dispose of. Therefore, water conservation and reuse are critical necessity for the textile industry because decreasing water and wastewater treatment and recycling costs can be beneficial.

This research neutralized the pH during dyeing industry wastewater treatment. The system should be robust to erroneous sensor measurements. A pH meter was developed and used to monitor the pH of wastewater hourly before and after HCl treatment.

HCl was used to neutralize the pH of wastewater from 9 to 7.5. The amount of HCl was optimized depending on the wastewater. Three wastewater treatment methods were used, namely, HCl, wash water and reverse osmosis (RO) treatments. The HCl treatment was the most effective for decreasing the pH; the wash water treatment was the most effective for decreasing the total dissolved solids (TDS), total suspended solids (TSS) total hardness and chemical oxygen demand; and the RO treatment was the most effective for decreasing the biochemical oxygen demand, TDS, TSS, total hardness and Cl⁻ concentration.

The pH should be monitored during the textile dyeing because the addition of color to textile fabrics is the most effective at neutral pH. This study evaluated several parameters of wastewater, including pH, color, TSS and TDS. The fabricated digital pH meter provided superior results than conventional measuring devices. The goal was to maintain a neutral pH during dyeing and recycle wastewater to improve environmental sustainability. The newly developed digital pH meter was less expensive and more precise than traditional pH meters. Before reusing and recycling, wastewater underwent ultrafiltration and RO treatment.

Higher education institutions have a significant impact in preparing future generations for the creation of a sustainable society. By formulating appropriate curricula, the university can shape student personality with sustainability concerns. This study aims to present the results of a teaching approach on environmental sustainability using the photovoice methodology. A guided visit to the sewage treatment plant of A Coruña was included as a teaching activity in the “Microbiology and Parasitology” classes of the podiatry degree at University of A Coruña. The teaching objectives were to reinforce contents through observation and to introduce citizen awareness on sustainability and responsible water use in a cross-sectional manner.

In this case study, different steps of photovoice as a qualitative participatory action methodology were developed. A total of 43 university students willingly participated with their photographs. Qualitative data were collected from the students’ photovoice visit reports and a subsequent discussion group. Thematic content analysis was performed manually.

This study explored the impact of an environmental sustainability teaching activity on the university student community. Six main categories emerged from the qualitative analysis: savings/waste of water, misuse of the water closet, disposing of used oil, solid waste/trash, reuse of clean water and reuse/reduction of the use of plastics. The cross-sectional findings on the needs of education and awareness of sustainability in the community and companies are presented.

The findings provide evidence of the ability of photovoice method as a pedagogical tool to promote reflection and change in the university community and to introduce sustainability cross-sectional content in green campus curricula. This photovoice experiment is simple and feasible to implement and has a very low economic cost, as long as there are qualified educators.

Provides a summary of recycled water use in California, illustrating the evolution of its application from individual projects for nearby users, to city‐wide and district programs. Presents three detailed case studies of recent water recycling projects: the West Basin Water Recycling project in Los Angeles County, the South Bay Water Recycling project in Santa Clara County, and several projects in Marin County. Barriers to recycled water projects include the cost, institutional barriers that separate water supply and wastewater functions, slow regulatory response in permitting, recognizing new technology and expended uses, and educating stakeholders. From the case studies, common elements to successful implementation demonstrate the importance of working with numerous stakeholders throughout the process and addressing their concerns, creating new institutional partnerships, educating stakeholders to bring actors together, market services, and engender support, acquiring financial assistance and providing incentives and, finally, relying on large volume users to support a more cost‐effective design.

Presents a survey of water, water pollution and control in China. Water shortage and water pollution are two of the most important environmental problems and factors affecting the development of industry, agriculture and the economy. China has made great efforts to improve environmental quality and has issued a series of important policies and regulations since the 1970s. Water saving and waste water reuse are the most significant measures implemented for solving the water shortage and controlling water pollution. All these policies and measures are playing an important role in alleviating and controlling the extent of water pollution.