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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 demand of sewage treatment plants is increasing day by day, especially in the countries like India. Biological and chemical unit of such sewage treatment plants are critical and needs to be designed and developed to achieve desired level of reliability, maintainability and availability.

This paper investigates and optimizes the availability of biological and chemical unit of a sewage treatment plant. A novel mathematical model for this unit is developed using the Markovian birth-death process. A set of Chapman–Kolmogorov differential equations are derived for the model and a generalized solution is discovered using soft computing techniques namely genetic algorithm (GA) and particle swarm optimization (PSO).

Nature-inspired optimization techniques results of availability function depicted that PSO outperforms GA. The optimum value of the availability of biological and chemical processing unit is 0.9324 corresponding to population size 100, the number of evolutions 300, mutation 0.6 and crossover 0.85 achieved using GA while PSO results reflect that optimum achieved availability is 0.936240 after 45 iterations. Finally, it is revealed that PSO outperforms than GA.

This paper investigates and optimizes the availability of biological and chemical units of a sewage treatment plant. A novel mathematical model for this unit is developed using the Markovian birth-death process.

Availability model of biological and chemical units of a sewage treatment is developed using field failure data and judgments collected from the experts. Furthermore, availability of the system has been optimized to achieve desired level of reliability and maintainability.

To investigate environmentally friendly alternatives for sludge disposal, three proportions of secondary sludge (SS) from two pulping processes (Kraft and TMP) were incorporated in the formulation of particleboard manufacturing. A 3² factorial design was used where the factors were Urea-formaldehyde (UF) content (5%, 7%, and 9% dry weight of resin per dry weight of particles) and secondary sludge percentage (75%, 100%, and 125% dry weight of SS per dry weight of resin). For each pulping process, 27 panels with SS and 3 control panels (without SS for each resin content) were made for a total of 63 panels. All panels were tested for thickness swell, linear expansion, internal bond strength (IB), flexural modulus of elasticity (MOE) and flexural modulus of rupture (MOR). Results indicated that particleboards made with SS from both pulping processes met the ANSI standards for linear expansion, IB, MOE and MOR. However, none of the tested panels met the standard for thickness swell and adding SS to the formulation affected negatively this property. It was concluded that SS from TMP and Kraft mills can be used to manufacture particleboard panels. However, its' percentage along with other additives' content should be optimized.

The treatment performance of two‐stage secondary treatment consisting of a trickling filter followed by activated sludge process for treatment of combined municipal and industrial wastewater is determined. The municipal wastewater treatment plant is located in Solon, Ohio, where the treatment units include grit tanks, primary clarifiers, trickling filters, aeration tanks, secondary clarifiers, tertiary filters and chlorine contact tanks. The treatment performance data for a 12‐month period in 1989 was evaluated. The average total plant flow was 2.82 MGD (millions gallons per day) which consisted of 2.19 MGD industrial wastewater and 0.63 MGD domestic wastewater. Raw wastewater was of a high strength mainly due to the contribution from industrial sources. After different degrees of treatment the values of total suspended solids (TSS) and biochemical oxygen demand (BOD) met US Environmental Protection Agency standards. This plant has good treatment performance with 99 per cent BOD and 98 per cent TSS removal efficiencies.

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.

The purpose of the project was to evaluate and demonstrate new solutions for decreasing the discharges from on‐site wastewater treatment plants.

The study evaluated several on‐site wastewater treatment plants. Seven of the investigated facilities were package plants, two were urine separating plants with large sand filters, two had storage tanks to collect wastewater separated from toilets and compact sand filters, and, finally, four had chemical precipitation in combination with large sand filters.

All of the systems have shown that they are able to remove more than 90 per cent of the phosphorus and more than 90 per cent of the organic matter. The sorting systems also give very low local emissions of nitrogen. To guarantee that the package plants perform well and manage to fulfil high reduction demands, there is a need for well functioning organisations for supervision and operation. The source separating systems require well‐informed and motivated users to achieve low discharges.

This study has been followed with great interest by national and local environmental authorities. Such ambitious evaluation of different on‐site wastewater treatment systems has never been done before in Sweden. The Swedish Environmental Protection Agency is expected to soon publish new demands for these systems. The results from the project have been an important input for the proposal of new national regulations.

It has been long debated whether the three bottom lines of sustainability (economic, environmental and social) can be achieved simultaneously or whether achieving one adversely affects the others. This paper analyses the economic sustainability of an environmental initiative, namely, effluent treatment plant (ETP), adopted by an Indian textile industry.

Two situations have been considered for the analysis. First, pure economic view with the operating and installed capacities has been considered. Second, combined economic-environmental view using shadow prices of undesirable outputs (biological oxygen demand, chemical oxygen demand, total nitrogen, total phosphorous, etc.) has been analysed.

It has been found that when pure economic view is considered, the net present value (NPV) of the ETP with present operating capacity (10,200 kL/day) is negative, implying that it is not economically sustainable. However, if the ETP is operated with the full installed capacity (17,000 kL/day), it becomes economically sustainable except in the case of very high cost of capital (13%). Finally, when shadow prices of undesirable outputs are considered, the NPV becomes positive, bolstering the economic-environmental sustainability of ETP.

In future, multiple case studies should be conducted in similar organisations to extend the general applicability of the outcome of this study. This research considers the economic and environmental aspects of ETP. However, social benefits have not been considered in this research work, which can definitely be addressed in future endeavours.

Though very high capital investment of ETP acts as a barrier, the results of this study imply that the top management of textile and clothing organisations should look at it from the holistic economic-environmental viewpoint. The use of ETP also leads to social benefits by improving the health of local community and by reducing their hospitalisation, medical expenditure and absenteeism from school and workplace. The outcome of this research may enthuse the entrepreneurs to adopt environmental initiatives.

The paper provides a framework to evaluate the economic feasibility of ETP by considering the time value of money. It is demonstrated with a real case that the environmental initiatives can be economically rewarding.

The purpose of this paper is to investigate the efficacy of bacterial exopolysaccharides (Eps) in reactive black 5 (RB5) textile dye wastewater bioremediation.

The Eps were produced by bacteria isolated from cotton gin trash soils collected from different cotton-growing regions in Kenya for comparison purposes. A broth medium reconstituted using molasses was assessed for its capacity to produce the Eps. RB5 textile dye wastewater was optimized for dye removal under different temperatures, times and molasses concentrations. Dye removal was studied by Lovibond-Day Light Comparator, UV–Vis spectrophotometer and FTIR.

It was found that cotton gin trash soils contained Eps-producing bacteria. Three of the Eps studied were found to have the capacity to remove at least 80% of the dye from the wastewater.

This research did not assess the efficacy of the RB5 dye removal from the wastewater by mixtures of the Eps.

Bioremediation of textile dye wastewater with Eps produced by bacteria cultured from cotton gin trash soil is significant because it will offer an effective and cleaner alternative to the chemical coagulants.

Alternative treatment of textile wastewater with the Eps would result in safer water being released into the water bodies as opposed to the chemically treated wastewater that contains remnant chemicals.

Research on the use of Eps produced by bacteria isolated from cotton gin trash soils for removal of RB5 dye from textile wastewater has not been done before.

A novel ternary flocculant was prepared by a simple compounding method to achieve efficient and rapid mud-water separation. This paper aims to discuss the possible mud-water separation mechanism.

This experimental study aims to investigate the effects of different types of flocculants on the separation of waste mud water and the degradation of flocculants in the supernatant. The flocculating component, the ratio of the flocculating accelerator to the flocculant and the addition amount of the novel ternary flocculant were optimized.

The experimental results show that the composition of the new ternary flocculant is cationic polyacrylamide (CP-02), grafted starch (GS-501) and flocculation sedimentation accelerator, the best effect, the mass ratio is 1:0.5: 0.75. According to 0.25:1 (volume ratio), the new ternary flocculant is pre-configured into a solution with a concentration of 3 kg/m³ to achieve efficient and rapid mud-water separation.

The new ternary flocculant is used for the separation of mud and water in the underground continuous wall waste mud, improving the level of civilized construction.