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The purpose of this paper is to assess and monitor a sample of heavy metals, namely lead, cadmium and copper, in water treatment plants at Greater Cairo, Egypt, to assess the efficiency of water treatment plants for metals removal and to monitor lead concentrations in the distribution system.

Water samples were collected from two water treatment plants. In addition, randomly flushed tap water samples from different districts at Greater Cairo were analyzed for lead concentration. Other water quality parameters also were monitored in water samples.

The study indicated that for water treatment plant intake, the mean concentrations were 4.44, 0.38 and 5.54μg/l for lead, cadmium and copper respectively. However, the final effluent shows that the mean concentrations of lead, cadmium and copper were 2.0, 0.15 and 2.78μg/l respectively. The drinking water mean metals concentrations were below World Health Organization drinking water guidelines and the Egyptian drinking water standards. The results revealed that water‐treatment plants have a high efficiency for metals removal where lead, cadmium and copper concentrations were reduced by 54.9, 60.5 and 49.8 per cent respectively. On the other hand, as expected, the water treatment plant sludge showed high accumulation with metals in concentrations decreased in the following order Fe > Mn > Zn > Cu > Cr > Ni > Pb > Cd. The mean lead concentration was 9.5μg/l in tap water samples.

Water treatment plants have a high efficiency for metals removal; water treatment plant sludge contains high concentrations of metals and should be treated before discharge; lead contamination from the distribution system is well established and lead concentration in homes in studied areas were higher than concentrations in plant effluent.

In Mexico, only 19.3 per cent of industrial water is treated (Green-Peace, 2014, pp. 3-4), whereas municipal treatment levels are approximately 50 per cent (CONAGUA, 2014a). This paper aims to focus on how the wastewater treatment plant policy, from a circular economy perspective, is affected by the governance context at the Presa Guadalupe sub-basin. Circular economy can contribute to water innovations that help in improving water quality. However, such benefits are not easily achieved. This case provides an example of the complexity and challenges that the implementation of a circular economy model can face.

Data are collected via semi-structured in-depth interviews with the stakeholders that are members of the Presa Guadalupe Commission. The contextual interaction theory (CIT) is the theoretical basis for this analysis (Boer de and Bressers, 2011; Bressers, 2009).

The findings show that the wastewater treatment plant policy plays an important role in a circular economy model. Some incentives towards a circular economy model are already in place; however, the hurdles of a top-down implementation perspective, low availability of resources, prioritisation of short-term results, lack of enforcement of the “polluter pays” principle and a linear model of water systems need to be overcome. If Mexico wants to move towards a circular economy model and if the government wants to enforce sustainable development principles, wastewater treatment is a challenge that must be addressed.

There are few studies in the circular economy literature that have analysed its implementation under a governance arrangement perspective.

A sustainable selection method for facility location of the water treatment is formulated by best–worst method. In addition, the model addresses the selection of appropriate technologies in the treatment plant, management of water leakage in the whole transmission network by using modernization and selection of different transmission technologies. Finally, the interaction between water and energy in this network seems to be paying particular attention.

Rapid population growth and urban development, and the constraints of water supply have become one of the crucial challenges around the world in the 21st century. Hence, the use of refined urban wastewater is increasing in many countries as an alternative source of water. In this regard, the rehabilitation of urban wastewater recycling and reuse has been proposed as one of the most suitable solutions for urban water management. Hence, in this paper, a mathematical model is formulated to design the simultaneous marketing of the urban water distribution network and wastewater treatment (including).

It seeks to ensure that energy is supplied through chemical methods to ensure that the system's energy dependence is on the national electricity grid. And in order to validate the model, a case study has been studied. By analyzing the results, it can be concluded that the upgrading of sewage treatment plants to replace underground water and water from nearby dams in household, agricultural and industrial applications will have positive environmental and economic impacts. One of the notable environmental impacts is the decline in groundwater and water scarcity in the coming years.

The summary of contributions is presented follow as: design and planning of water and urban wastewater integrated network; sustainable selection of facility location for the water treatment; capability selecting different treatment technologies in simultaneous design water and urban sewage supply chain; managing water leak in the network; proposed a water–energy nexus model in simultaneous design water and urban sewage supply chain; studying the feasibility of construction of power plants from biogas, the resulting of anaerobic digestion in treatment centers.

The paper seeks to review some of the main operational problems of wastewater treatment plants designed for nutrient removal. It aims to pay particular attention to bulking and foaming due to massive growth of filamentous organisms, failure or non‐optimal operation of secondary settling tanks, and compliance with more stringent effluent requirements.

The discussion of the major operational problems is based on a thorough review of the available literature and own experiences with more than 80 wastewater treatment plants.

To suppress the undesirable growth of filamentous organisms and to achieve an all‐year round stable operation of secondary settling tanks several design options for improvement have been developed based on the experience gained so far. The most desirable option for improving the operation of a single treatment plant is to a large extent site specific. Beside adopting the design procedures also operational measures are possible.

The paper recommends several practical options for optimising the performance of wastewater treatment plants with regard to the aforementioned problems. These recommendations are based on proved practical experience and, therefore, may act as a flexible toolbox for an individually tailored design or operation of the plant in order to avoid and/or combat the problems during operation.

The described options for improvement the operation are based on long lasting practical experience with large scale wastewater treatment plants. They can be used by any operator of such plants for solving some of the major problems of modern wastewater treatment plants.

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.

In treating both sewage and storm runoff, wastewater treatment plants are important to maintaining a healthy environment. If the plant operations managers do not respond correctly to plant conditions, environmental damage resulting in the deterioration of human health may be the result. Unfortunately, there are no formal models to help these managers; they rely upon their own intuition to manage the plants. The purpose of this paper is to investigate the effectiveness of various models, originally used for manufacturing, to detect process conditions in wastewater treatment facilities. We compare and contrast the performance of five statistical models and three neural network architectures. The data used in the research is 527 daily measurements of 38 sensor readings of the process state variables of an urban wastewater treatment plant.

The purpose of this paper is to investigate the organizational change taking place within New Zealand water utilities as a result of implementing Total Quality Management (TQM) models (i.e. TQM experts’ teachings, ISO 9000 standards, and quality awards). Implementation was intended to enhance their performance and the quality of drinking water provided to the community.

This study was conducted by investigating the quality management system in three different case studies from the Waikato Region of New Zealand. The main study methodology is involved in methodological triangulation in which the researcher used more than one technique for data collection and data analysis. This paper reports on two of those techniques: face to face interviews conducted with the managers of the three case studies under investigation; and participant observation at the water treatment plants of the same three territorial local authorities (TLAs).

The comparative analysis drawn between the three different cases showed that two of the case studies are applying TQM models but at different stages, while the third case study is not implementing any of the TQM models. The difference between the performances of TLAs adopting a TQM model versus the TLAs who are not is related to their organizational strategy. This in turn has an impact on the sustainability of the quality of water provided to the community of the Waikato Region.

The paper emphasises the importance of breadth and depth of organizational change in the three TLAs in view of the following themes: training personnel in quality systems, customer satisfaction with water quality, purchasing equipment/chemicals, process control, inspection and testing, calibration, corrective and preventive action where drinking water is below standard (non‐conformance) and control of quality records.

The paper provides a useful case of TQM application in water utilities services.

This paper represents an analytical study conducted in the laboratory. The purpose of this paper is to monitor changes of some parameters related to water treatment in Hamman Bebagh (Bouhamdane Watershed).

This study was focused on three sites: river water, dam water and treated water during the first six months of 2014 (January-June). It included 16 physico-chemical parameters (PH, T, conductivity, etc.) and two bacteriological (E. coli, fecal streptococci). These parameters were analyzed to make a comparison between stagnant dam water (before and after treatment) and river water.

The obtained results over the whole period of analysis indicated that treated dam water was less loaded with organic materials, solids, dissolved salts (Cl⁻, Ca²⁺, and Mg²⁺) that were deposited at the bottom of the dam than dam water before treatment. On the other hand, river water was found to be more charged of suspended matter than the dam water and the treated water since flowing water carried all materials in its course. In terms of bacteriological quality, treated water was found to be free from all traces of bacteria analyzed that were present in the dam and the river before the treatment.

This study was proposed in order to see if it is necessary to establish a second treatment plant in the medium term. On the basis of this analysis, the end results have shown that the treatment plant was effective enough to reach the desired goal (treated water which respects the norms of OMS).

Wastewater treatment plants (WWTPs) have long-time environmental impacts. The purpose of this paper is to assess the environmental footprint of two advanced wastewater treatment (WWT) technologies in a life cycle and sustainability perspective and identify the improvement alternatives.

In this study life cycle-based environmental assessment of two advanced WWT technologies (moving bed biofilm reactor (MBBR) and sequencing batch reactor (SBR)) has been carried out to compare different technological options. Life cycle impacts were computed using GaBi software employing the CML 2 (2010) methodology. Primary data were collected and analysed through surveys and on-site visits to WWTPs. The present study attempts to achieve significantly transparent results using life cycle assessment (LCA) in limited availability of data.

The results of both direct measurements in the studied wastewater systems and the LCA support the fact that advanced treatment has the best environmental performance. The results show that the operation phase contributes to nearly 99 per cent for the impacts of the plant. The study identified emissions associated with electricity production required to operate the WWTPs, chemical usage, emissions to water from treated effluent and heavy metal emissions from waste sludge applied to land are the major contributors for overall environmental impacts. SBR is found to be the best option for WWT as compared to MBBR in the urban context. In order to improve the overall environmental performance, the wastewater recovery, that is, reusable water should be improved. Further, sludge utilisation for energy recovery should be considered. The results of the study show that the avoided impacts of energy recovery can be even greater than direct impacts of greenhouse gas emissions from the wastewater system. Therefore, measures which combine reusing wastewater with energy generation should be preferred. The study highlights the major shortcoming, i.e., the lack of national life cycle inventories and databases in India limiting the wide application of LCA in the context of environmental decision making.

The results of this study express only the environmental impacts of the operation phase of WWT system and sludge management options. Therefore, it is recommended that further LCAs studies should be carried out to investigate construction and demolition phase and also there is need to reconsider the toxicological- and pathogen-related impact categories. The results obtained through this type of LCA studies can be used in the decision-making framework for selection of appropriate WWT technology by considering LCA results as one of the attributes.

The results of LCA modelling show that though the environmental impacts associated with advanced technologies are high, these technologies produce the good reusable quality of effluent. In areas where water is scarce, governments should promote reusing wastewater by providing additional treatment under safe conditions as much as possible with advanced WWT. The LCA model for WWT and management planning can be used for the environmental assessment of WWT technologies.

The current work provides a site-specific data on sustainable WWT and management. The study contributes to the development of the regional reference input data for LCA (inventory development) in the domain of wastewater management.