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This study explores the optimization of iron electrocoagulation for treating laundry greywater, which accounts for up to 38% of domestic greywater. Characterized by high concentrations of surfactants, detergents, and suspended solids, laundry greywater presents complex challenges for treatment processes, posing significant environmental and health risks. Utilizing response surface methodology (RSM), this research developed a second-order polynomial regression model focused on key operational parameters such as the area-to-volume ratio (A/V), current density, electrolysis time, and settling time. Optimal treatment conditions were identified: an A/V ratio of 30 m2/m3, a current density of 10 mA/cm2, an electrolysis duration of 50 min, and a settlement period of 12 h. Under these conditions, exceptional treatment outcomes were achieved, with turbidity removal reaching 94.26% and COD removal at 99.64%. The model exhibited high effectiveness for turbidity removal, with an R2 value of 94.16%, and moderate effectiveness for COD removal, with an R2 value of 75.90%. The interaction between the A/V ratio and electrolysis time particularly underscored their critical role in electrocoagulation system design. Moreover, these results highlight the potential for optimizing electrocoagulation parameters to adapt to daily fluctuations in greywater production and meet specific household reuse needs, such as toilet flushing. This tailored approach aims to maximize contaminant separation and coagulant efficiency, balance energy use and operational costs, and contribute to sustainable water management. [ABSTRACT FROM AUTHOR]

The obsolete efficiencies in conventional centralized wastewater treatment systems call for implementation of source separation and treatment of wastewater. Approximately 60–75% of domestic wastewater is attributed to greywater, which could be reused to combat freshwater crisis. The present study investigates qualitative and quantitative attributes of greywater from different sources in High-Income Countries (HICs) and Low-Income Countries (LICs). The quantity of greywater generation is positively correlated with country's per capita income, but feebly negatively correlated with temperature. Kitchen source is the highest contributor of total suspended solids (134–1300 mg/l), whereas in case of turbidity, laundry is the major contributor (39–444 NTU). Also, kitchen greywater is characterized by comparatively high biochemical oxygen demand (BOD) of 100–1850 mg/l, low pH of 5.6–8, and elevated total nitrogen (TN) of about 1.5–48 mg/l. The high pH (7.3–10) and chemical oxygen demand (COD) levels (58–2497 mg/l) in laundry greywater are due to usage of sodium hydroxide-based soaps, while usage of wash detergents containing phosphates like sodium tripolyphosphate contribute to high total phosphorus (TP) (0.062–57 mg/l). The qualitative characteristics of greywater in HICs are perceived to be superior compared to LICs. Furthermore, the most widely used physicochemical, biological, and advanced oxidation treatment technologies for greywater are outlined briefly. It can be observed that economical treatment systems like phytoremediation or biological technologies combined with sand filtration systems can be implemented to treat greywater with high organic content in LICs, whereas in HICs where greywater is generated in large quantities, electro-coagulation combined with advanced oxidation technologies can be used to treat its higher COD levels. Highlights: Assessment of variations in qualitative and quantitative characteristics of greywater from various sources and in HICs and LICs. The quantity of greywater generation is positively correlated with the per capita income, but feebly negatively correlated with the temperature aspect of the country. Kitchen is the major source of BOD5 and TN, while laundry is the major contributor of COD and TP in the greywater. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Jordan's limited water resources have reduced daily water consumption, leading to a highly concentrated greywater production rate of 54 million cubic meters per year. The presence of nitrate ions, total dissolved solids, total suspended solids, chemical oxygen demand, and biological oxygen demand in greywater poses excellent environmental and health risks when disposed untreated. Water scarcity directly impacts water and food security and is expected to intensify at the current resources management practices. The significance of the current and predictable water shortage in the context of sustainable development and the presence of new technologies brought further attention to utilizing non-conventional water sources. Reclamation of treated wastewater, greywater, brackish, and seawater desalination is Jordan's water budget's only non-conventional water resource. This study aims to address Jordan's water scarcity crisis by developing a low-energy, solar-powered greywater filtration system using natural materials while ensuring compliance with Jordanian standards for safe agricultural applications. METHODS: Several treatment methods have been proposed; however, most of these systems require high to medium energy levels for treatment purposes. Hence, the running cost of the system is relatively high. To address this issue, a four-stage, low-energy, green, and decentralized solar filtration system for greywater treatment has been developed, which uses natural materials available in Jordan and activated carbon to reduce organic and solids content and remove pathogens. The system also uses hot water generated by a Photovoltaic solar system to sanitize the greywater, a novel concept of approach for sanitization. This innovative system is powered entirely by solar energy and can be installed in individual homes. FINDINGS: The results of the developed solar filtration system were very efficient in reducing turbidity, chemical oxygen demand, and Escherichia coli removal: 92, 95, and 100 percent, respectively. Furthermore, the system showed a high potential for total coliforms and Escherichia coli inactivation, reaching 4.64 and 3.15 log units, respectively. Product water meets Jordan standards, ensuring safe reuse for irrigation applications. The findings of this study highlight the satisfactory performance of the developed greywater solar filtration setup. The economic feasibility analysis demonstrates that the proposed system is economically viable and financially sound. The system's reliance on solar energy and the absence of consumables contribute to its sustainability. They are addressing sustainable practices in greywater treatment in addition to water scarcity concerns. CONCLUSION: The treated greywater, obtained through the series of treatment steps, including solar disinfection, successfully met the Jordanian standards for safe reuse. The substantial reduction of Escherichia coli and total coliforms to acceptable levels demonstrates the treatment system's effectiveness in generating pathogen-free greywater, suitable for a wide range of applications. The study concludes that the solar filtration setup consistently delivers high-quality, pathogen-free greywater, meeting stringent regulatory requirements. This innovative, sustainable system offers a viable solution to Jordan's water scarcity, introducing a new non-conventional water resource that requires no consumables (non-chemical, non-hazardous materials), thereby addressing sustainability concerns in greywater treatment. [ABSTRACT FROM AUTHOR]

Due to increasing freshwater demand and limited availability of resources, conservation and recycling of greywater are getting attention worldwide. Greywater (GW) is considered a potential contender to different types of industrial wastewater in terms of recyclability, toxicity, and reusability. The reuse and treatment methodologies in the case of LGW mainly depend on parameters such as pH, Biochemical oxygen demand (BOD), Chemical oxygen demand (COD), Total dissolved solids (TDS), Total suspended solids (TSS), turbidity, ionic concentration, surfactants, and microbial growth. Available literature suggests that domestic as well as commercial laundries are major contributors to greywater around the globe. This paper presents the results of investigations conducted on the quantity and quality of greywater generated from domestic urban laundries. Various factors were observed that influence the quantity of generated LGW such as family size, type of washing (machine or manual), and composition of LGW influenced by the work profile of family members, etc. The average values of BOD, COD, TSS, TDS, turbidity, Chloride (Cl−), Sulphate (SO42−), Fluoride (F−), Nitrate (NO3−), and anionic surfactants as MBAS (methylene blue active substances) were observed as 265.73 mgL−1, 1754.67 mgL−1, 469.13 mgL−1, 1837.73 mgL−1, 281.8 NTU, 438.6 mgL−1, 87.93 mgL−1, 0.87 mgL−1, 6.83 mgL−1, and 16.45 mgL−1, respectively. The average concentration of Escherichia coli and total coliforms was observed to be 73.4 MPN/100 mL (most probable number per 100 mL) and 386.2 MPN/100 mL, respectively. The high values of selected parameters necessitate the planning of greywater treatment in urban locations for re‐utilization. This study also revealed that a huge amount of freshwater is being converted to greywater by domestic laundries that can be re‐utilized for non‐potable purposes after some treatment. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the efficiency of a combined cheese wastewater treatment approach involving coagulation with ferric chloride coupled with a photo-Fenton-like oxidation process for potential reuse in irrigation. Laboratory-scale tests were conducted, examining the effect of various operational parameters on the treatment process. Specifically, the effects of initial wastewater pH, coagulant dosage, decantation time for the coagulation process, and initial pH, chemical oxygen demand (COD) concentration, and Fe3+ and H2O2 dosages for photo-Fenton-like oxidation were studied. Coagulation was found effective at natural pH of 6 and showed a highest removal efficiency in terms of COD (50.6%), biological oxygen demand BOD5 (42.1%), turbidity (99.3%), and least sludge volume generation (11.8% v/v) for an optimum coagulant dose of 400 mg Fe3+ L–1 and 8 h of decantation time. Thereafter, photo-Fenton-like oxidation (Fe3+/H2O2/UVA-300W) of the pretreated cheese effluent enhanced the removal of COD, BOD5 and TOC to 91.2%, 91.4%, and 97.5%, respectively, using the optimized conditions (pH = 3; [Fe3+] = 5.0 × 10−4 mol L−1; [H2O2] = 0.2 mol L−1 and tirr = 24 h). This study also shows that the proposed combined process allowed a significant phytotoxicity reduction toward lentil seed germination. The obtained outcome was encouraging and supports the possible use of the treated cheese wastewater as an additional water source for agricultural irrigation. [ABSTRACT FROM AUTHOR]

A rise in population and urbanization demanded that a robust fecal sludge management (FSM) value chain be used to restructure the sanitation system throughout the world securely. A significant global need exists to adopt efficient and sustainable FSM. On-site sanitation systems (OSS) produce fecal sludge (FS). FS is produced when excreta and blackwater are combined and stored or treated, either alone or in combination with greywater. FS can be semisolid or slurry and raw or partially digested. Critical examination of FS characteristics, i.e., biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), and pathogen count, varies from 600–56,836 mg/l, 6656 to 201,200 mg/l, 830–123,000 mg/l, and 105 to 109E. coli/l of FS respectively. Helminth eggs range from 2500–25,000/l of FS. Public health and the environment are negatively impacted by septic tank overflows and the careless discharge of FS into open spaces affecting groundwater quality, water bodies, irrigation fields, open drains, places outside villages, etc. Thus, deciding on a proper treatment technology for FS before discharging it into open land or reusing FS is essential to create a pollution-free environment. This paper highlights the practices adopted for FSM under its different processes, such as collecting, characterization, treating, and reusing of on-site FS and bibliometric analysis on documents on fecal sludge. A thorough analysis has been carried out by reviewing all important literature available globally. [ABSTRACT FROM AUTHOR]

In this paper, greywater samples are collected from the kitchens of different types of buildings (residential and commercial) located in different districts within the city of Jeddah, Saudi Arabia. The collected samples are analyzed and compared with the potable water from the same region. The parameters investigated are pH, conductivity, total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), total hardness, temporary hardness, permanent hardness, alkalinity, chloride, and biochemical oxygen demand (BOD). It was found that the amount of total suspended solids is very high in the greywater samples. It shows the presence of both temporary and permanent hardness. Their alkalinity values are greater than hardness. It may be due to the number, lifestyle, age of the occupants, presence of children, and social and cultural behavior of residents. The concentration of BOD level is very low, which shows that the greywater samples have lower concentrations of organic compounds. Design details of the greywater treatment plant are suggested based on the results of the analysis. This includes a screening chamber, grit chamber, settling tank, and filtration unit. The treated greywater is recommended for reuse for gardening, landscaping, and toilet flushing purposes. [ABSTRACT FROM AUTHOR]

This study addresses a persistent environmental concern related to graywater discharge from households, highlighting its potential to contribute to increased pollution in water bodies. To mitigate this issue, the research explores the use of subsurface flow‐built wetlands, specifically focusing on the innovative application of constructed tidal and vertical flow wetlands (CTWFWs) as wastewater treatment systems. The study not only evaluates the efficacy of these CTWFW systems but also delves into the crucial aspects of their operation and their interactions with the biological, physical, and chemical characteristics of graywater. A key innovation of this research is the investigation of zeolite's effectiveness and the utilization of perlite‐based plant species in both mixed and monoculture configurations to develop lab‐scale hybrid constructed wetlands (HCWs). These HCWs are designed for the removal of organic matter and nutrients from graywater, offering a sustainable and cost‐effective solution to this environmental challenge. The study also examines the dynamic processes involved in graywater treatment, emphasizing how the removal of parameters like biological oxygen demand (BOD), nutrients, total suspended solids (TSS), and disinfection efficiency can significantly impact the effectiveness of treatment systems. Furthermore, the research scrutinizes the intricate relationship between the treatment unit's dimensions and the specific criteria that need to be met for efficient graywater treatment. Intriguingly, the study tracks the changes in graywater composition and the treatment process over time. By conducting on‐site measurements of various physicochemical characteristics such as temperature, dissolved oxygen (DO), electrical conductivity (EC), turbidity, total dissolved solids (TDS), and pH, the research offers a comprehensive understanding of the treatment system's performance and adaptability. The study dives into the microbial communities within the treatment systems, utilizing 16S rRNA amplicon sequencing to characterize the complex microbial ecosystem present in graywater. This approach sheds light on the interplay between microorganisms, physicochemical conditions, plant responses, substrate dynamics, and the production of microbial metabolites. It underscores the holistic nature of the research, encompassing various aspects of graywater treatment. Notably, the study explores the application of biochar in combination with the target heavy metal, cadmium (Cd), within constructed wetlands (CWs). This innovative approach aims to better understand the kinetics and isothermal adsorption of lead in the context of mouthwash residue, expanding the knowledge base in this critical area. The research findings are substantial, with remarkable removal efficiencies achieved for parameters like TSS, turbidity, chemical oxygen demand (COD), nitrate, and phosphate. These results underscore the practicality and effectiveness of the proposed treatment methods. This holistic and pioneering research significantly advances the understanding of sustainable graywater treatment, offering valuable insights and practical solutions to mitigate water pollution concerns. Practitioner Points: This study addresses a persistent environmental concern related to greywater discharge from households, highlighting its potential to contribute to increased pollution in water bodies.The study not only evaluates the efficacy of these CTWFW systems but also delves into the crucial aspects of their operation and their interactions with the biological, physical, and chemical characteristics of greywater.A key innovation of this research is the investigation of zeolite's effectiveness and the utilization of perlite‐based plant species in both mixed and monoculture configurations to develop lab‐scale hybrid constructed wetlands (HCWs). [ABSTRACT FROM AUTHOR]

To solve the upcoming environmental problems, sponge city concepts as well as new technologies are being developed these days. One of the future challenges is to reduce drinking water demand by using decentralized water recycling systems. This study aimed to investigate the performance of a specially designed pilot wetland roof (PWR) treating domestic greywater (GW) at ground level under outdoor conditions and to evaluate the effects of different hydraulic loading rates (HLRs) for a period of two years. The results showed highly efficient removal of typical greywater pollutants from the system, e.g., five-day biochemical oxygen demand (BOD5) > 96%, chemical oxygen demand (COD) > 93%, total suspended solids (TSS) >94%, anionic surfactants (AS) > 94%, ammonium-nitrogen (NH4-N) > 84%, total nitrogen (TN) > 71%, total phosphorous (TP) > 87%, and E. coli (1.86 ± 1.54 log-removal). The mean concentrations of the targeted parameters at the outflow were in compliance with the requirements for discharge to the environment and met reclaimed water quality standards for agricultural irrigation, except for E. coli. Statistically significant (p < 0.05) results of pollutant mass removal rate across different HLRs indicated the potential effect of HLR on treatment performance, and HLR in a range of 67–80 L m–2 d–1 contributed to a higher removal efficiency without compromising the limit values. A comparatively low HLR of 45 L m–2 d–1 should be applicable if pathogen removal is the most important requirement. Plant species showed good plant vitality and adapted well to the water storage mat. The higher the mean ambient air temperature, the greater runoff reduction (>50%) was observed due to high evapotranspiration. The results showed the system is a promising green technology for GW recycling and can be scaled up for application to urban buildings. [ABSTRACT FROM AUTHOR]

One of the innovative approaches to supplying water demands for irrigation and recreational purposes is the treatment and reuse of greywater. However, during the coronavirus pandemic, greywater has the potential to be polluted by SARS-CoV-2. Therefore, it is unsafe to reuse it during the peak of the COVID-19 outbreak. In this research, a membrane bioreactor combined with an ultraviolet disinfection system is applied to treat the greywater and remove the SARS-CoV-2 virus up to the required quality for irrigation or flush tank purposes. The results showed membrane bioreactor could remove 94.3 ± 1.2% of initial chemical oxygen demand and be partially successful in virus removal. Fifty percent of secondary treated effluent samples were still positive for SARS-CoV-2 RNA. The results also illustrated that ultraviolet disinfection could reduce faecal and total coliform by more than 99% and eliminate the SARS-CoV-2 virus. The tertiary treated effluent biochemical oxygen demand, chemical oxygen demand, and total coliform were 1.7 ± 0.2 mg/l, 18 ± 1.2 mg/l, and below 3 MPN/100 mL, respectively. Moreover, all of the samples of the tertiary treated effluent were negative for coronavirus RNA. Therefore, the tertiary treated effluent characteristic satisfied Iran's standards for wastewater reuse in irrigation. [ABSTRACT FROM AUTHOR]

Wetlands technology is one of the main sustainable and successful treatment processes. Similarly, biochar is an organic, effective, and low-cost adsorbent material used for the treatment of diverse wastewaters. The combination between wetland system and biochar, as a media, can greatly enhance the treatment efficiency. The aim of this study is to assess the performance of two horizontal flow constructed wetlands planted with Bacopa monnieri L. for the treatment of household greywater. The objectives were to investigate the raw and treated greywater characteristics, compare the removal efficiency of pollutants by using gravel bed, and biochar-gravel bed, monitor the growth and survival of the plants. Findings indicated that the simulated treatment systems were able to improve all the greywater characteristics. The wetland with biochar enhanced the removal efficiency of biological oxygen demand (BOD5), ammonia (NH3), and other parameters compared with the wetland with gravels alone. [ABSTRACT FROM AUTHOR]

Urban planning management should consider wastewater as a challenge. Wastewater, in this case, grey water, is full of dangerous contaminants and, at specific concentrations, can turn into a substance that affects the environment. The effluent of the released waste must therefore be managed to ensure that it complies with the government's quality standard criteria. The membrane bioreactor (MBR) technology process produced waste effluents with low concentrations of biological oxygen demand (BOD5), chemical oxygen demand (COD), and total organic carbon (TOC), proving its higher efficiency as a biological processing stage. Total coliforms and E. coli are not present in processed products, detergents and total suspended solid (TSS) are effectively degraded. This is made possible by the considerably lower organic load; as a result, biomass accumulation slows and mixed liquor suspended solids (MLSS), which have low value, are produced. With the assistance of continuous airflow, and without the use of chemicals or backwashing, an ultrafiltration module (UF) with a membrane cut-off size small enough to be able to create a constant permeate flux during the grey water treatment process is necessary. Although processed grey water does not pass denitrification, all parameters linked to the quality of the effluent water exceed environmental quality criteria. [ABSTRACT FROM AUTHOR]

With an objective to develop a closed loop wastewater biorefinery, the performance of two free floating aquatic weeds water hyacinth (Eichhornia crassipes, Mart, Solms) and salvinia (Salvinia molesta, Mitchell) is explored when either is used as the main bioagent for treating sewage in "sheet flow root level" (SHEFROL) bioreactors. Both the macrophytes prove to be easy to propagate and maintain while they are able to help in achieving significant primary, secondary, and tertiary treatment steps of greywater in a single step. Water hyacinth is able to remove suspended solids, chemical oxygen demand (COD), biological oxygen demand (BOD), total Kjeldahl nitrogen, soluble phosphorous, zinc, copper, nickel, and manganese to the average extents of 81%, 79%, 43%, 41%, 40%, 36%, 34%, and 29%, respectively. The reduction in COD and BOD levels achieved by salvinia is marginally lesser than by water hyacinth but in terms of the removal of other pollutants, the performance of salvinia is comparable to that of water hyacinth. It is possible to convert the dead or harvested plants to organic fertilizer thus making it a closed‐loop system with no waste of its own. [ABSTRACT FROM AUTHOR]

Aims and Background: In recent decades, recycling of wastewater has received increasing attention among researchers, because it can satisfy the proliferating demand for groundwater and reduce water shortages in developed and developing countries. Methods: A deep learning technique, CapsNet, was developed to predict the optimal plant for household greywater treatment. Then, a greywater treatment system was developed by utilizing phytoremediation technology with horizontal flow wetland construction to utilize the final treated water for organic gardening. Results: Evaluation parameters like color, odor, temperature, pH, electrical conductivity, free residual chlorine, chloride, sulfate, Salmonella spp, Total Dissolved Solids (TDS), Total Suspended Solids (TSS), oil and grease, sulfide, Chemical Oxygen Demand (COD), E. coli, Biochemical Oxygen Demand (BOD), and Nitrate Nitrogen were used to analyze the performance of the greywater treatment system. Conclusion: The experimental outcomes showed that Typha angustifolia achieved an effective outcome in greywater treatment compared with other plants, where most of the parameter values of the effluent were low compared with those of the influent. Most of the parameters like pH and TDS were higher than those of the groundwater aquifers, but fell within the world health organization safety limits. [ABSTRACT FROM AUTHOR]

Due to India's population expansion, water recycling is critical to reducing water scarcity. The purpose of this study is to discuss the recycling and reuse of domestic greywater. The horizontal subsurface flow constructed wetland (HSSF-CW) was employed to treat greywater, with bioenergy crops replacing decorative plants. CO 86032 and CO 15027 sugarcane varieties were employed for phytoremediation. In a laboratory-scale HSSF-CW system with dimensions of 0.92 m, 0.61 m, and 0.45 m, coarse aggregate (20 mm), brick jelly (20 mm), and red soil mixed with coir pith (1/3 of coir pith volume-based) were employed as filter materials. During a hydraulic retention time (HRT) of 2 to 48 h, the maximum removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and total nitrogen (TN) was 77.78–90%, 69.92–81.20%, 82–91.06%, and 75.83–84.02%, respectively. [ABSTRACT FROM AUTHOR]

Laundry processes are huge water consumers and contribute to wastewaters in high volume. In the current report, treatment of greywater (GW) was studied from commercial laundry in BITS Pilani, KK Birla Goa Campus, India, which produces around 2–2.5 m3/day of GW. Source laundry GW showed physicochemical parameters like chemical oxygen demand (COD), biochemical oxygen demand (BOD5), ammoniacal N (NH4–N), nitrate (NO3–N), nitrite (NO2–N), orthophosphate (PO4–P) and pH in the range of 600–650 mg/L, 350–370 mg/L, 9–12 mg/L, 15–21 mg/L, 14–22 mg/L, 28–35 mg/L and 7.48–8.10, respectively. The treatment system included French‐type two‐stage vertical flow constructed wetland (VFCW) preceded by anaerobic filter tank filled with 3D plastic support. Wetland beds were made up of sand and gravel as filter media, and Canna indica was used as macrophyte. Pretreatment by anaerobic filter resulted in the increase in residence time of GW and reduction of pollutant load to wetland beds, thus preventing clogging of Stage 1 wetland. Sampling and water quality data analysis was performed weekly for 26 weeks. Outlet pollutant levels showed 96.35% removal of organic matter, 79.93% removal of nitrogen and 95.04% removal of orthophosphates. The pH of outlet water was 7.35, which is well below discharge permissible limits. Treated water quality was below Central Pollution Control Board (CPCB), India, permissible limits for discharge, and the cost of treating GW by the system is 1.11 USD/m3 which is very feasible in country like India. Treated water is suitable for nonpotable options like gardening of central lawns in BITS Pilani Goa, floor cleaning of laundry and construction purpose. [ABSTRACT FROM AUTHOR]

Algae-based membrane bioreactor (AMBR) has shown a potential for simultaneous wastewater treatment and production of algal biomass. However, the effectiveness of AMBR has yet to be further explored for greywater treatment. The present study assessed the algal biomass production, greywater treatment efficiency, and fouling characteristics of a laboratory-scale AMBR. The 12 h dark/12 h light cycle continuous experiments were performed with an AMBR operating at 48 h hydraulic retention time. The average algal biomass and chlorophyll-a production rates were 47.9 mg/L/d and 49.9 μg/L/d, respectively. The distribution of different pigments in the biomass showed an abundance of chlorophyll-a (92.2%) in the reactor. AMBR achieved 96% biological oxygen demand (BOD5) removal and 99% anionic surfactants removal by bacterial oxidation without any external aeration source. Algal assimilation achieved a total nitrogen removal of 52% and total phosphorus removal of 36%. More than 85% of nitrite (NO3-N) in the effluent revealed the absence of nitrification and denitrification processes in the reactor. Further, the reactor accomplished a higher than the 3.5-log reduction of total coliform and E-coli. The greenish cake layer of algal–bacterial biomass primarily caused the membrane fouling and accounted for 80–93% of total fouling resistance. Membrane fouling frequency decreased with the operation time, and physical cleaning effectively recovered the flux. The energy efficiency of AMBR in terms of net energy return (1.04) supported its application for the treatment and recycling of greywater. The present study provides the basis for establishing the guidelines for AMBR design for the treatment of greywater. [ABSTRACT FROM AUTHOR]

Constructed wetlands (CWs) have great potential as low-cost natural wastewater treatment in developing countries. The present study appraises the performance of the vertical flow constructed wetland for domestic wastewater treatment. More specifically, the potential of Canna Indica in the removal of carbon, nitrogen, and phosphorus (CNP) from wastewater under tropical conditions. CW cell was fabricated with a vegetative layer of Canna Indica and tested with domestic wastewater. Based on the test results, Canna Indica shows a high Removal Efficiency (RE) of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD5) on the order of 87% and 91%, respectively. Similarly, nutrients removal efficiency for total nitrogen (TN), total phosphorus (TP) was found to be 97% and 98%, respectively. The investigation also revealed that there is considerable removal of sulfates with efficiency equal to 78.4%. Overall, the Canna Indica based CWs were found to be suitable for wastewater treatment in the tropical regions, provided a viable medium for treating the wastewater in peri-urban and rural areas of developing countries. This study investigates the performance of Canna indica based vertical flow wetlands for greywater treatment. The study investigates the results at different hydraulic retention times and loading rates. There are no much studies reporting the performance of this variety of plant species under a tropical humid climate. The results from the study can encourage adoption of this plant variety, indigenous to this part of the country, for wastewater treatment It could emphasize the importance of familiarity with constructed wetlands to comprehend the RE of various climatic zones. It is possible to highlight the Canna-based CW's efficiency in removing organics and nutrients from domestic wastewater. The possibility for field-scale Canna-based CW to remove pollution in tropical climates was investigated, and Decentralization of wastewater treatment at the household level to apply CWs that will improve wastewater quality. [ABSTRACT FROM AUTHOR]

Water is essential to support daily life, ecosystem, environment, and development. Due to rapid industrialisation, population growth, and economic development, the water demand increases worldwide. For this reason, research is being conducted to find alternative sources of water for non-potable purposes. Domestic greywater is receiving much attention worldwide as a possible alternative water supply for domestic and productive purposes. This study aims to determine the water quality index (WQI) for domestic wastewater and evaluate the effectiveness of Iron Removal Media (IRM) and Cattail Typha Angustifolia plants in treating greywater. The domestic wastewater used for treatment was wastewater from laundry activities. There are two types of models designed to obtain different data for both media. The first model design is used with Iron Removal Media and the second model is with Cattail Typha Angustifolia plants. After the greywater treatments, the efficiencies of different treatments were observed and compared to the WQI standard. It was found that the removal efficiencies were 25% for biochemical oxygen demand (BOD), 23% for chemical oxygen demand (COD), 12% for total suspended solids (TSS), and 9% for pH using IRM. When Cattail Typha Angustifolia media was used, the removal efficiencies of 57% for TSS, 46% for COD, 45% for BOD, and 10% for pH were achieved. This study showed that using Cattail Typha Angustifolia plants as media for the greywater treatment process could be more effective as compared to IRM. [ABSTRACT FROM AUTHOR]

In this experimental research, it is aimed at evaluating a novel composite ceramic membrane for treating and recycling on-site greywater. Therefore, three types of tubular microfiltration ceramic membrane including Mullite, Mullite/SiC and Mulite/SiC/AC composite were fabricated and sintered at a relatively low temperature (1250 °C) under N 2 atmosphere. Field Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) analyses showed that the presence of silicon carbide and activated carbon can improve the surface roughness. Besides, the changes in open porosity, radial and longitudinal shrinkage, mean pore size and mechanical strength were measured and compared for the pure Mullite and composite membranes to determine the most appropriate membrane for the treatment of greywater. The highest pure-water permeability of 3954 kg/m2h.br was associated with the Mullite/SiC/AC membrane with the highest porosity of 64.7% and an acceptable appropriate mechanical strength (17.2 MPa approx.). Furthermore, the highest removal efficiency was related to Mullite/SiC/AC in comparison with Mullite and Mullite/SiC membranes. It was observed that using the Mullite/SiC/AC membrane, the removal efficiencies for chemical oxygen demand (COD), biochemical oxygen demand (BOD), total sulfate, total nitrate, phosphate, and detergent (ABS) were 88.0%, 87.0%, 71.5%, 86.5%, 94.3%, and 40.4%, respectively. [ABSTRACT FROM AUTHOR]

Current methods of treatment are often insufficient to purify greywater and household sewage; therefore, the presented study was aimed to assess the impact of ultraviolet irradiation and titanium( IV) oxide on the content level of organic substances and ammonium nitrogen, which are potential pollutants. The levels of organic contaminants were analyzed based on indicators used in the qualitative water and wastewater analyses. The chemical oxygen demand, the five-day biochemical oxygen demand, as well as ammonium nitrogen were all included in our determination. Two series of experiments on greywater and septic tank effluent were performed as a basis of the study. In each experiment, samples were irradiated with UV light in the presence or absence of various forms of TiO2 as a photocatalyst. The results indicate that the use of UV light irradiation on its own and also in the presence of TiO2 significantly influences the composition of greywater and domestic wastewater in relation to organic compounds and ammonium nitrogen. The decrease in N–NH4 was found in both experiments on septic tank effluents in the presence of TiO2 with simultaneous UV irradiation. [ABSTRACT FROM AUTHOR]

Greywater (GW) can be separated in different fractions where the kitchen component might be included. Constructed wetland (CW) systems are commonly used for the onsite treatment of GW, and the fraction treated might impact the performance, operation, and maintenance. These aspects are still poorly explored in the literature and are of importance for a proper design and system sustainability. In this study, a multi-stage household-scale CW system composed of a horizontal flow (HF), followed by a vertical flow (VF) unit, was monitored over 1330 days, focusing on different GW fractions and hydraulic and organic loading rates. The biochemical oxygen demand (BOD) was ~50% lower without the kitchen sink component (GWL) in the system inlet, while no drop was observed in the chemical oxygen demand (COD). Treatment with the GWL component caused a sudden drop in the hydraulic loading rate applied at the HF-CW (~114 to 35 mm per day) and the VF-CW (~230 to 70 mm per day). Even when the HF-CW received ~90 gCOD m−2 per day (GW), the multistage system reached a COD removal of 90%. The lower BOD load when treating GWL avoids clogging and decreases the frequency of maintenance. These variables can be used for the optimal design and operation of a CW, contributing with empirical data to CW guidelines in Brazil, and could additionally be expanded for application in other countries with similar climates. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the performance of individual units of waste stabilisation ponds (WSPs) system treating domestic wastewater. The study was conducted by measuring the concentrations of physiochemical parameters and bacteriological indictors in the influent and effluent samples of each pond. The thickness of sludge was determined by measuring depths of sludge layer in each pond. Knowing the performance of each pond will speed up targeted intervention to improve performance. The influent was mainly characterised by 224, 500, 270 mg L−1, 258 Nephelometric Turbidity Unit (NTU) respectively, of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), turbidity and 35600 coliform forming units/100 ml of faecal coliforms. Bacteriological counts were fluctuating and effluent faecal coliforms counts were 1.22 × 104 ± 2.0 × 102 coliform forming units/100 ml. The hydraulic retention times (HRTs) decreased by 2.0, 13.6 and 7.2 days in the first three ponds and by 3.3 days in the last three ponds. Biochemical oxygen demand in the final effluent was 40 mg L−1 more than the design value of f 25 mg L−1. Chemical oxygen demand in the final effluent was 190 mg L−1, higher than the prescribed limit of 150 mg L−1 of discharge into rivers. Total suspended solids in the final effluent was 150 ± 127 mg L−1 more than the national limit of 25 mg L−1. Total suspended solids and turbidity correlated positively with bacteriological indicators, but there was no correlation with temperature except with faecal coliforms. There was also no correlation observed between suspended solids and pH. The treatment system did not meet the design treatment criteria because of overloading as a result of increased population which exceeded the design value. The final effluent from the system did not meet the discharge limits, therefore, it is unsuitable for discharge into the environment as it can pollute ground and surface waters as well as the open environment. Knowledge on the performance of each pond will help in proper interventions to be undertaken at the targeted pond or unit. It is therefore eminent to desludge each pond as a short‐term solution and expand the system for a long‐term solution. [ABSTRACT FROM AUTHOR]

The fisheries sector is one of the most ancient and important sectors in the world and plays a significant role in providing the nutrition and socio-economic development of the country. The fish processing industry produces huge quantities of wastewater, encompassing significant amounts of contaminants in the form of soluble, colloidal, and particulate matters. The disposal of shellfish waste is a serious issue, and the effluents discharged from seafood-processing plants contain high amounts of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), dissolved solids, suspended solids, and turbidity. The existing waste management system lacks a cost-effective and environmentally friendly method. The current research focus on the extraction of a biopolymer chitosan from crab shells by ecofriendly methods and its application in refinery wastewater treatment. The chemical structure and crystallinity of the extracted chitosan was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analyses. Surface morphology and elemental composition were determined using Scanning Electron Microscopy (SEM), and Energy-Dispersive X-Ray Analysis (EDX). Thermal properties were detected using Thermo Gravimetric Analysis (TGA). The extracted chitosan was successfully employed in the batch treatment of refinery effluent by varying the experimental parameters (refinery effluent solution pH, contact time, dosage of chitosan, and stirring speed) and the optimizations of the processing conditions were established. [ABSTRACT FROM AUTHOR]

Sand Intermittent Filtration (SIF) is an established technology of wastewater treatment and in recent years it gains renewed interest due to its simplicity and less energy requirement. The aim of the present study was to evaluate the modified filter-bed Reactor using Sand-intermittent-filtration (SIF) for the removal of physicochemical parameters viz dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total hardness (TH), calcium hardness (CaH), chloride (Cl), turbidity, total solids (TS), total dissolved solids (TDS), and total suspended solids (TSS) of the Industrial wastewater of State Industrial Development Corporation of Uttarakhand Limited (SIDCUL) at Haridwar. The experiments were performed with the composition of the filter-bed having sand and gravel in the ratio of 1:1 (Reactor I); 1:2 (Reactor II) and 2:1 (Reactor III) at the room temperature 300C. Each Reactor was categorized into A, B and C type based on depth of filter-bed (A=10 cm, B=15 cm, C=30 cm). The maximum removal of TS (52.21%), TDS (50.66%), TSS (57.20%), turbidity (67.36%), chloride (28.81%), BOD (39.18%), COD (38.66%), TH (53.40%), and CaH (62.57%) was observed in Reactor II C (soil and gravel-2:1 and 30 cm depth of bed) using 0.49 mm effective size and 0.49 uniformity coefficient (UC) of the sand. A mixture of sand and gravel in the Reactor II with a ratio of 2:1 yielded better efficiency in comparison to the Reactor I and Reactor III. Thus, SIF technology could be environment-friendly and economically cost-effective for removing various physicochemical parameters from Industrial wastewater. [ABSTRACT FROM AUTHOR]

The studies on utilization of natural coagulants prepared from seeds of Citrullus lanatus (watermelon) and Cucumis melo (cantaloupe) provide insight on sewage wastewater treatment. The results were statistically analyzed by response surface methodology (RSM) based central composite design (CCD), and supported with results from Fourier Transform Infrared (FTIR) spectroscopy for functional groups present in coagulants. The batch coagulation studies were performed varying process parameters such as pH (5-7) and coagulant dosage (50-150 mg/L) at constant flocculant dosage of 10 mg/L using jar test. In jar test, coagulation was carried out with fast mixing (Mixing at 150 rpm for 1 min) followed by slow mixing (Mixing at 50 rpm for 30 min), and the final mixture was allowed to settle for 1 h at the temperature of 30±2ºC. Design-Expert® version 12 software was used to optimize pH and coagulant dosage for effective sewage wastewater treatment using natural coagulants with the objectives to maximize percentage reduction in turbidity, biological/biochemical oxygen demand (BOD), total suspended solids (TSS), and chemical oxygen demand (COD). The RSM results reveal that the optimum C. lanatus coagulant dosage of 72.3 mg/L at pH 5 achieved maximum efficacy removal of TSS and BOD by 92.8% and 92.1% respectively. The FTIR results show that the coagulants from plant seeds contain almost similar functional groups. Thus, it can be concluded that the coagulant prepared from C. lanatus would be more effective for treatment of sewage wastewater. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Every year, a large amount of mineral processing wastewater is discharged from various industries into the environment which is considered a challenging task not only because of its large volume, but more importantly, its hazardous components, while its reuse as feedwater without proper treatments causes great harm to the final product of these industries. Cost-effective methods are required to treat a wide range of industrial wastewater in a diverse range of conditions. In this study, a combined hydrocyclone-electrocoagulation system is tried to treat the wastewater for industries with high water consumption and high pollutants such as paper industry, iron and metal forming industry, and marble industry. The effects of the hydrocyclone operational parameters, such as feed inlet pressure and diameter, vortex finder diameter, apex diameter, and feed solids content, were investigated. In the case, wastewater of paper industry, the following optimum conditions (P = 4.5 bar, !" = 15.8 mm, !# = 6 mm, !$ = 4 mm and %& = 2.3%) were achieved. An overflow of about 90.58% water recovery and 21.45% solid at 75.92% separation efficiency was obtained. The results showed that the hydrocycloneelectrocoagulation treatment has efficiently treated the three different types of industrial wastewater. The chemical oxygen demand (COD), biochemical oxygen demand (BOD), total solid (TS), total suspended solids (TSS), colour and turbidity, were reduced sharply and met the effluent discharge or reuse standards. Also, compared with the hydrocyclone-treated wastewater, the hydrocyloneelectrocoagulation- treated wastewater was found to be more enhanced. [ABSTRACT FROM AUTHOR]

Supplying treated greywater within buildings delivers continuous additional resilience and improvements in water efficiency. This includes the making available (by substitution) of greywater resources suitable for non-potable purposes such as flushing toilets. Thereby, the overall daily consumption of pristine potable water for flushing and other lower quality uses is reduced. The empirical measurement of turbidity was confirmed as an accurate and resilient indicator of greywater quality, greywater treatment process efficiency and of well-functioning greywater reuse systems in the short-, medium- and long-term. The methodology applies turbidity monitoring for evidential management and control of treated greywater quality, essential for greywater recycling in the building stock. The results demonstrated evidence of co-variation between turbidity and biochemical oxygen demand in a lightly-loaded greywater treatment process. Real-time monitoring of turbidity delivers responsive, reliable, in-situ and remote measurements for informing building management systems (BMS), comprising an essential part of routine monitoring of greywater treatment plant. The analytical evidence confirms the importance of turbidity measurement and control in both current and future UK and international greywater standards. By undertaking turbidity measurements in compliance with BS 8525−2:2011, greater assurance in the use and compliance of greywater supplies in the built environment is achieved. Consequently, the rationale for including the empirical measurement of turbidity to demonstrate satisfactory management of the greywater quality, treatment system operation, monitoring and compliance in buildings has been confirmed. [ABSTRACT FROM AUTHOR]

Evaluating the quality of river water is a critical process due to pollution and variations of natural or anthropogenic origin. For the Soan River (Pakistan), seven sampling sites were selected in the urban area of Rawalpindi/Islamabad, and 18 major chemical parameters were examined over two seasons, i.e., premonsoon and postmonsoon 2019. Multivariate statistical approaches such as the Spearman correlation coefficient, cluster analysis (CA), and principal component analysis (PCA) were used to evaluate the water quality of the Soan River based on temporal and spatial patterns. Analytical results obtained by PCA show that 92.46% of the total variation in the premonsoon season and 93.11% in the postmonsoon season were observed by only two loading factors in both seasons. The PCA and CA made it possible to extract and recognize the origins of the factors responsible for water quality variations during the year 2019. The sampling stations were grouped into specific clusters on the basis of the spatiotemporal pattern of water quality data. The parameters dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, and total suspended solids (TSS) are among the prominent contributing variations in water quality, indicating that the water quality of the Soan River deteriorates gradually as it passes through the urban areas, receiving domestic and industrial wastewater from the outfalls. This study indicates that the adopted methodology can be utilized effectively for effective river water quality management. [ABSTRACT FROM AUTHOR]

The study was carried out to meet a certain level of water quality for reuse. It was undertaken to evaluate the removal efficiency of some pollutants from greywater (chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total nitrogen and total phosphorus) on a lab-scale. The experimental set-up has consisted of a preliminary Lamella settler combined with a filter reactor made of geotextile pocket filled with activated carbon and medium or fine sand. The lab-scale set-up has removed more than 70% of COD and BOD5, 75% of total phosphorus, 45% of total nitrogen in the raw greywater. Treated greywater from the installation has met requirements for irrigation in water shortage areas. [ABSTRACT FROM AUTHOR]

One of the important alternative water sources for non-potable purposes is greywater, but needs to remove contaminants. The aim of this study was to investigate the performance of a horizontal series filter (HSF) consists of sand, zeolite (Z), pumice (P), and granular activated carbon (GAC) to analyse the chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total dissolved solids (TDS), turbidity, and pH in greywater samples from Fasa University Student Hostel, Iran. Recycling treatment was performed by passing the greywater through filters. After the last filter, treated greywater was returned into the main tank. The system was run at filtration rate of 2.94 m3 day−1. The analysis of the data from the filtration tests showed that GAC is the best adsorbent for removing COD, BOD5, and TDS from greywater, followed by zeolite. Whereas, pumice is more advisable to remove turbidity. However, due to the different mass of adsorbents in the filters, pumice showed a higher adsorption capacity than zeolite. Generally, the triple combination of GAC+Z + P represented the best performance in the reduction of COD, BOD5, TDS, turbidity up to 90.42%, 91.43%, 82.95%, and 90.27%, respectively. Therefore, the studied system can be implemented in public places to greywater treatment and reuse. [ABSTRACT FROM AUTHOR]

Copyright of Ceramica is the property of Associacao Brasileira de Ceramica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Usuma Dam is the major source of potable water in the Federal Capital Territory, Abuja, Nigeria. The physicochemical properties of water and sediment of the dam was assessed in this study to determine its quality. Electrical conductivity, pH, nitrate, phosphate, total dissolved solids, total suspended solids, turbidity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, chloride, total hardness, phosphate, nitrate and sulfate were determined in the water samples. Total organic matter, total organic carbon and particle size were among the parameters analyzed in sediments. The parameters were within recommended limits except for biochemical oxygen demand and chemical oxygen demand which were more than the recommended limit of 10 mg/L and 30 mg/L respectively. The total organic matter and the total organic carbon in the sediment samples were between 1.56±0.27 - 2.85±0.20% and 0.13±0.03 - 0.96±0.03% respectively. The particle size was in the following order: sand > silt > clay. The results of this study confirmed the presence of high organic and inorganic matter in the dam from non-point pollution sources occasioned by storm water from poorly planned settlements around the dam and runoffs from agricultural practices. [ABSTRACT FROM AUTHOR]

Aquaculture practices are steadily increasing to meet the fish demand, especially in tropical countries like India. However, efforts to characterize the contribution of these aquaculture ponds towards greenhouse gas emission like CH4 are still very few. CH4 concentration in water [pCH4(water)] and air–water CH4 fluxes were estimated (during the summer months) in two sewage-fed ponds having different depths situated in the East Kolkata Wetlands, India (a Ramsar site). pCH4(water) in both of these ponds showed significant positive correlation with water temperature (R2 = 0.68 and 0.71, p < 0.05). Daily mean chlorophyll-a, turbidity, biochemical oxygen demand (BOD) and gross primary productivity (GPP) also showed positive correlation with pCH4(water). This indicated that higher primary production and presence of turbid materials acted as substrates for methanogenesis, which favoured air–water CH4 effluxes towards atmosphere. Mean air–water CH4 fluxes in the ponds having depth of 1.1 m and 0.6 m were observed to be 24.79 ± 12.02 mg m−2 h−1 and 6.05 ± 3.14 mg m−2 h−1 respectively. Higher depth facilitated net heterotrophic conditions, which led to lower dissolved oxygen levels, which, in turn, led to lower rate of CH4 oxidation. Moreover, under reduced photosynthetically active radiation (in the pond having greater depth), the pH values were comparatively lower (~7.7), which further facilitated a favourable condition for the methanogens to grow. On the whole, it was inferred that apart from pre-established physicochemical factors, depth was also found to play a decisive role in regulating the air–water CH4 fluxes from these aquaculture ponds. In future, continuous sampling should be carried out (by chamber method) to take into account the ebullition CH4 fluxes, and more number of ponds should be sampled throughout a complete annual cycle to have a more holistic understanding about this cluster of sewage-fed aquaculture ponds. [ABSTRACT FROM AUTHOR]

Dried and grounded pineapple peel and crown waste materials were carbonized at 270°C and activated with H3 PO4 and ZnCl2 at an impregnation ratio of 1:1. The activated carbon (AC) characteristics were investigated based on their yield, moisture and ash content, volatile matter and bulk densities. Also, their surface morphology and functional groups were analyzed using scanning electron microscopy (SEM), Brunauer–Emmett–Teller, Barrett–Joyner–Halenda analysis and Fourier transform infrared, respectively. Biochemical oxygen demand (BOD), total dissolved oxygen (TDS), pH and turbidity were tested before and after the treatment of kitchen wastewater. The results from various pollution contaminant indicators demonstrate the effect of contact time in the reduction of pH, BOD, TDS and turbidity and from observations; an increase in contact time yields an increase in the reduction of all the contaminants indicators tested. H3PO4 -activated pineapple peel (PPPAC) produce the highest percentage yield and bulk density to be 58.15% and 0.42 g/cm³ compared to others, based on the physicochemical characterization and investigation of the treated wastewater, PPPAC performed better in the reduction of pH and percentage removal of BOD when compared to ZnCl2 -activated pineapple peel (PPZAC), while ZnCl2 -activated pineapple crown (PCZAC) performed better in the reduction of pH, and percentage removal of TDS and BOD when compared to H3 PO4 -activated pineapple crown (PCPAC). [ABSTRACT FROM AUTHOR]

Background and Objective: Increased untreated wastewater and unsustainable development of agriculture has deteriorated water quality of rivers. The aim of this study was to determine the quality of water in Gorganrud River basin using NSFWQI IRWQISC and Liou Pollution Index and compare them with the global standards. To do this, GIS software.was used Materials and Methods: In this study, 5 sampling stations were selected based on standard criteria including land use type, accessibility and standard distributions along the river. 12 water quality parameters including dissolved oxygen, fecal coliform, pH, biochemical oxygen demand, chemical oxygen demand, temperature, organic phosphate, nitrate, ammonium, turbidity, total dissolved solids and electrical conductivity in river for one year were measured from June 2019 to May 2019 follwoing standard methods. Results: The amount of phosphate and turbidity was increased along the river from station 2 to the mouth of the river. This was due to the presence of agricultural and municipal sewage. There was a significant difference in BOD, fecal coliforms and nitrates with those of the standard values. Water quality indicators showed the great effects of urban wastewater and human waste in the river area. The best quality was observed in Station 1 (75; Good Quality), which was less exposed to human activity and development. Based on the conformity of the results of the indicators with the terrestrial reality, the results of the IRWQIsc index (Iranian surface water quality) showed the best results due to compatibility to the land uses and the trend of variables. Conclusion: The presence of urban sewage and unsustainable agricultural in the city of Gonbad Kavous is the most important reason for the decline in water quality (poor quality class). In this regard, a comprehensive management in water resources and environmental impact assessment is needed. [ABSTRACT FROM AUTHOR]

Résumé: L'emploi de toilettes sèches mobiles (TSM) se généralise en France depuis une vingtaine d'années, sans qu'il n'existe d'encadrement clair de la gestion des matières générées. Les éventuels impacts sanitaires que peut engendrer la mise en place de telles filières de traitement des urines et matières fécales sont étudiés ici. Cette analyse vise à proposer ensuite des axes d'évolution réglementaire. Un état des lieux des pratiques, des représentations du risque sanitaire et de la réglementation en vigueur a été réalisé. Il a permis de cibler sept événements correspondant à quatre filières de pratiques différentes qui ont été caractérisées. Ces quatre filières (urines, urines avec litière, matières fécales avec litière en plateforme individuelle, matières fécales avec litière en plateforme collective) sont les plus représentatives des pratiques de collecte, transport, traitement et valorisation des urines et matières fécales hors du tout-à-l'égout. L'évaluation des risques sanitaires associée à chaque maillon de ces filières démontre qu'aucune mesure particulière n'est à mener pour les matières de TSM par rapport aux consignes et règles d'hygiène générales pour les filières « eaux usées/excreta ». Il est toutefois proposé une meilleure reconnaissance administrative de ces matières pour faciliter leur accès aux plateformes de compostage collectives, car elles sont aujourd'hui peu acceptées. L'obtention du diplôme maître-composteur (module GC25 du référentiel de l'Agence de l'environnement et de la maîtrise de l'énergie [ADEME]) pour l'opérateur de plateforme individuelle est une bonne garantie de réduction des risques pour la gestion de ces matières. Although portable dry toilets have become widespread in France over the past 20 years, there is no clear administrative framework for managing the materials they generate. This study analyzes the possible health impacts of urine and feces management in order to propose regulatory changes. It inventories practices, representations of the health risk and the regulations in effect. We targeted 7 events and characterized 4 different types of practice. These 4 channels (urine, urine with litter, feces with bulking material in an individual platform, feces with bulking material in a collective platform) are the most representative of the "collection, transport, treatment and recovery" of urine and feces that do not enter the ordinary sewage system. The assessment of the health risks associated with each link in these sectors shows that no special measures need to be taken for dry toilet matter under the general hygiene guidelines and rules for the "wastewater/excreta" sectors. However, we suggest that better administrative recognition of this issue is needed, the standards governing collective composting platforms require them to accept this matter, and that individual platform operator should obtain an officially recognized diploma. [ABSTRACT FROM AUTHOR]

Water quality parameters of Holy River Ganga was analyzed at two major sites, namely, Triveni Ghat (Rishikesh) and Har ki Pauri (Haridwar) situated at Uttarakhand (India) between March 2016 and February 2018 to find out the extent of pollution in the river by using water quality index (WQI). Values of most of the parameters, viz., turbidity (7.79 NTU), pH (7.24), total dissolved solids (217.46 mg/l), biochemical oxygen demand (2.10 mg/l) and total hardness (90.69 mg/l) were found higher in the rainy season. During the study, it was observed that as the holy River Ganga flows from Rishikesh to Haridwar, the values of certain parameters, such as pH (7.22), biochemical oxygen demand (2.58 mg/l), total dissolved solids (201.92 mg/l) and total hardness (107.13 mg/l) increase. Similarities and variations between the parameters were analyzed by a multivariate statistical method like principal component analysis (PCA), Pearson correlation coefficient, cluster analysis (CA), t-test, etc. Pearson correlation matrix of physicochemical parameters strongly correlates with each other indicating the inter-dependency of the variables. Seasonal similarity in summer and winter in dendrodram shows the impact of anthropogenic activity on the water quality of the Ganga River. The value of WQI indicates better water quality at Rishikesh (35.23) than that at Haridwar (47.34). The study concludes that water of the Ganga River at both sites can be used for domestic and agricultural purposes but precautions and extensive measures are necessary before consumption. [ABSTRACT FROM AUTHOR]

The present study aimed to assess the effect of greywater discharged into the drainage system on DO concentrations using the Streeter–Phelps model. The result revealed that biochemical oxygen demand (BOD5) was 172 mg/L, chemical oxygen demand (COD) was 400 mg/L and pH was 4.5. The highest BOD5 loading rate for daily flow rate was observed at Drain (III) with the values of 63 kg/d and 369 m³/d. These drains have a high frequency of household activities and number of occupants leads to high amount of pollutant loading rate produced from greywater drainage. Moreover, the assessment of greywater pollution modelling was measured using Streeter–Phelps model. The DO deficit (Dt) and time critical (tc) were 3.54 and 3.80 mg/L and 0.007/d, respectively, as recorded at the distance of 10 m upstream (Station1) of the discharge point. The findings show that the degradable organic matter and travel time as a critical oxygen deficit point occurred at 10 m upstream as the kinetics of BOD reaction. Hence, the greywater discharge with mixing stream showed no risk of pollution occurrence near the river flow in this study. [ABSTRACT FROM AUTHOR]

The freely and abundantly available amphibious plant Indian pennywort Bacopa monnieri (L.) Pennell was able to phytoremediate sewage (greywater) quickly and substantially in SHEFROL® ("sheet flow root level") bioreactors, achieving reductions in the levels of several indicator parameters: suspended solids, chemical oxygen demand, biological oxygen demand, nitrogen, phosphorus, zinc, copper, nickel, and manganese to the extents of about 90%, 76–77%, 80%, 65%, 55%, 56%, 42%, and 41%, respectively at hydraulic retention times of just 6 h. As these indicators of primary, secondary, and tertiary treatments were achieved simultaneously in a single reactor compartment, the system presented in this paper promises to be simple, rapid, and economical, in achieving significant treatment of greywater. [ABSTRACT FROM AUTHOR]

The conventional treatment system adopted by Indian and Global Tanneries consist of (i) Segregation of Spent Chrome Stream and discharge of supernatant for combined treatment along with effluent from all sectional operations starting from soaking to finishing, (ii) Conventional physiochemical and biological treatment for reduction of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), etc., (iii) Ultra-filtration and Reverse Osmosis (RO) system for recovery of water and Multiple Effect Evaporator (MEE) for the evaporation of RO reject stream and generation of mixed salt in case of Zero Liquid Discharge (ZLD) system and (iv) Storage of mixed salt recovered from the MEE system for which no viable disposal system is found. Establishment of treatment system for the mixed stream results in poor performance of biological treatment units, increases the O&M cost, and accumulation of recovered mixed salt in case of ZLD system. It is estimated that, more than 8-10 tons of mixed salt is generated during the treatment of 1.0 MLD effluent under ZLD system. To address this serious environmental problem, an innovative approach of segregation of saline streams such as soak liquor and chrome liquor are planned to be collected separately with the feasibility of recovering reusable quality salt and chromium in the form cake for regeneration and use in the form of Basic Chromium Sulphate (BCS) by the tanneries. This innovative treatment concept has been developed and is being implemented in many CETPs in India. This will become the first of its kind in Global Leather World. This developmental scheme is in accordance with the guidelines and recommendations of UNIDO in terms of sustainability of ZLD system for the leather sector. The technological developments on cleaner productions, centralized chrome recovery reuse system, segregation of saline soak water for separate treatment with recovery of water and quality salt are dealt in this technical paper. [ABSTRACT FROM AUTHOR]

This research was aimed at studying the possibility of efficiently combining Mangifera indica and Phoenix dactylifera seeds powders as coagulants in wastewater treatment. The seeds were characterized for their composition, active compounds and proximate constituents using atomic adsorption spectroscopy, Scanning Electron Microscopy, and X-ray Diffraction analysis. Jar test was carried out using the seeds extracts separately and in combination at varying dosages and the Electrical Conductivity, Total Dissolved Solids, Chemical Oxygen Demand, Biochemical Oxygen Demand, Turbidity, Temperature, pH, and Total coliform were measured with every varying dosage. Statistical tools were used to validate the results of the Jar test. The sludge from the Jar test experiment was analyzed for its total nitrogen, organic carbon, organic matter, total volatile solids, and carbon: nitrogen ratio. Mangifera indica removed 89% turbidity, 96% BOD, 84% COD and 99% total coliform of the wastewater. Phoenix dactylifera removed 75% turbidity, 85% BOD, 78% COD and 88% total coliform of the wastewater. Their combination removed 96% turbidity, 96% BOD, 87% COD and 98% total coliform of the wastewater. [ABSTRACT FROM AUTHOR]

The efficacy of the Moringa oleifera (MO) in wastewater treatment has been well studied and documented. However, there exists a significant gap in exploring the operating conditions to optimize the wastewater treatment process. This study investigated and optimized the removal efficiency of turbidity, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) from municipal wastewater under the operating conditions of pH (5-7), MO dosage (50-200 mg/L), and settling time courses (60-240 min) using face-centered central composite design (FCCCD) of response surface methodology. The experimental results of FCCCD were fitted to the second-order quadratic model to approximate the effects of each variable factor and their interactions on the responses of interest in a mathematical relationship and consequently, predict the process responses. The obtained results revealed that under the optimum operating conditions of pH, MO dosage, and settling time of 6.01, 182.74 mg/L, and 228.08 min, respectively, the predicted values of turbidity, BOD, and COD removal efficiencies were 98.20%, 92.96%, and 78.82%, respectively, with the desirability of 1.000. This study demonstrated the effectiveness of FCCCD with a desirability function to optimize the process conditions (pH, MO dosage, and settling time) of coagulation for the turbidity, BOD, and COD removal efficiencies. [ABSTRACT FROM AUTHOR]

Industrialization, population growth, and urbanization are the main causes for the generation of increasing quantities of municipal wastewater (MWW) which, untreated, pose a serious threat to natural aquifers. In order to protect the environment and natural resources, it is necessary to use high-efficiency and environmentally friendly technologies for the treatment of MWW. The goal of this work was treatment of MWW with advanced membrane processes; membrane bioreactor (MBR) and nanofiltration (NF) and reverse osmosis (RO). Laboratory and pilot treatment of MWW with MBR resulted in a reduction of more than 92 % in chemical oxygen demand (COD), biochemical oxygen demand (BOD5), turbidity and suspended matter. The number of microbiological parameters decreased by 4.12 log10 to 4.88 log10. Subsequent treatment of MBR effluent with RO/NF membranes (XLE and NF270) further reduced all measured parameters. [ABSTRACT FROM AUTHOR]

Halda River, the lone natural carp breeding ground in Bangladesh as well as in Southeast Asia is an economically important river and its water quality is deteriorating due to unplanned industrialization and various anthropogenic activities. The present research work has been conducted to assess the characteristics of HR water. Eighteen water quality parameters were studied including pH, temperature, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Dissolved Solids, Electrical Conductivity, Hardness, Turbidity, Total Alkalinity, SO4 2-, PO4 3-, NO3 -, Cl-, NH4 +, Cr (VI), Mn (II) and Arsenic. This study shows that water in HR is regularly alkaline and its pH lies between 7.08-7.65. The DO value varies from 5.9-8.4 mgL-1, BOD ranged from 0.3-2.8 mgL-1 and COD from 24-96 mgL-1. According to the Water Quality Index study, the river is being intensely polluted due to the unscrupulous industrial wastes discharge into the HR through various canals. [ABSTRACT FROM AUTHOR]

The intermittent nature of stormwater runoff impacts the treatment performance of biofilters, also known as stormwater biofiltration or bioretention systems and raingardens. During extended dry periods, which are common even in temperate climates, plants can perish, creating unattractive and non-functional systems that might leach pollutants during the next rainfall event. The current solution is to irrigate during long dry spells, which is costly and unsustainable as biofilters become more widespread. This paper presents the development of dual-mode biofilters, where stormwater and greywater are treated within the same system. Fifty columns, utilising eight plant species, including understory and climbing ornamentals, and designs with and without a carbon source in the submerged zone, were subjected to alternating greywater and stormwater inflows over five months. Six sampling events investigated treatment performance across these switching inflows and an extended dry period (atypical event). Good removal of total suspended solids (>83%), biochemical oxygen demand (>86%) and some heavy metals (e.g. lead >96%) were reported irrespective of design. Plant species selection was critical for the removal of nitrogen (2 to 79%) and phosphorus (12 to 75%) under dual-mode operation. However, following the extended dry period, plants with the lowest nutrient outflow concentrations also experienced some of the highest sediment and carbon concentrations, suggesting that a mixture of plant species may be beneficial for withstanding abnormal conditions. Differences between the treatment performance of designs with and without a carbon source were negligible, with potential benefits possibly negated due to the increased root mass that comes with age (systems were approximately two years old) and the release of carbon from root exudates. The results demonstrate the potential for dual-mode stormwater-greywater biofilters as an alternative to single-mode systems as they can provide effective treatment, along with greater volumes of treated water, while maintaining system performance throughout the year. Image 1 • Dual-mode stormwater-greywater biofilters can provide effective treatment. • High removal of sediment, carbon and some heavy metals irrespective of design. • Plant species selection is vital for effective removal of nitrogen and phosphorus. • No practical significance for including a carbon source in the saturated zone. • Ornamental and climbing plants can be utilised in dual-mode biofilters. [ABSTRACT FROM AUTHOR]

In this study coagulation-flocculation method was evaluated to treat municipal wastewater using aluminum sulphate and calcium hydroxide as coagulants, and polyacrylamide as flocculant by varying pH from 5 to 7 and coagulant dosage from 100 to 300 mg L-1 at constant flocculant dosage (10 mg L-1), time (1 min for rapid mixing followed by 30 min for slow mixing), temperature (30°C ± 2°C), agitation speed (150 rpm for rapid mixing followed by 50 rpm for slow mixing) and settling time (2 h) by jar test method. The responses were percentages reduction in turbidity, chemical oxygen demand (COD) and biochemical oxygen demand (BOD). The sample was real-time wastewater from sewage treatment plant of Salalah Sanitary Drainage Services (SSDS) Company, Salalah, Sultanate of Oman. The trials were performed with single and mixed or combined coagulants. Response surface methodology (RSM) based central composite design (CCD) was used for the optimization of pH and coagulant dosage to maximize percentage reduction in turbidity, COD and BOD. The maximum of 99.7%, 98%, and 95.5% were achieved for turbidity removal using aluminum sulphate, calcium hydroxide and combined coagulants respectively. However, maximum of 60%, 58.1%, and 42.5% were achieved for COD removal using calcium hydroxide, combined and aluminum sulphate respectively. Moreover, maximum of 79.5%, 78.5%, and 54.5% were achieved for BOD removal using aluminum sulphate, calcium hydroxide and combined coagulants respectively. The obtained results indicate that treatment using combined coagulant is effective for removal of turbidity and COD, and could be used for the treatment of municipal wastewater. [ABSTRACT FROM AUTHOR]