Search

The industrial laundry sector is a major user of water and chemicals such as surfactants, and one of the largest producers of wastewater. Although treated wastewaters comply with regulations, they still contain contaminants. Here we review laundry wastewater with focus on industrial laundry activities and their challenges, chemical composition of wastewater, and treatment techniques. We discuss advantages and drawbacks of treatment techniques that can be used as secondary treatment in already existing plants, or as tertiary treatment, i.e., complementary to an existing treatment. We observe that laundry is an expanding industrial sector with increasing water requirements, an abundant use of chemical substances, and increasingly stringent discharge regulations. There is a lack of chemical and biological knowledge on aqueous discharges. Moreover, the chemical composition, temporal variability, treatment information, and environmental and ecotoxicological data are poorly reported. The composition of wastewaters and additives, and their temporal variability are also poorly known. Similarly, detailed information on treatments is rare, and environmental and ecotoxicological data are poorly reported. Finding a tertiary water treatment process that is efficient, viable, and environmentally friendly is challenging since wastewater volumes are very high and contaminants are present at trace level in complex organo-mineral mixtures. [ABSTRACT FROM AUTHOR]

Considering the increasing need for optimal use of water resources, using types of waste water instead of part of the water for making concrete and also reducing the use of potable water in concrete is particularly important, especially in developing countries. Accordingly, this study aimed to investigate and reinforce using greywater as a potential alternative to mixing water in concrete. The specimens' fresh, hardened, and durable properties from 14 concrete mix designs containing six mixing water types, three natural zeolite levels (0, 10, and 20%), and two silica fume levels (0 and 8%) were tested to achieve that. Mixing waters in this study consisted of distilled water, raw greywater, diluted greywater (50% greywater, 50% distilled water), simulations of greywater's salt and organic pollutants, and synthetic greywater. The results showed that raw greywater reduced average compressive strength by 8%, while diluted greywater caused a 1.5% increase instead. Mixing water standards requirements were satisfied on both raw and diluted greywater cases. The results also showed that the impact of greywater on the durability properties of concrete was non-critical in most cases, while diluted greywater, even slightly (4%), improved bulk electrical resistance (RCPT). The test results of synthetic waters showed that reducing chemically active salts and/or organic pollution in greywater can effectively increase the performance of the produced concrete. Using 8% silica fume as cement replacement improved the compressive strength of greywater-made concrete by up to 16% and reduced the cracks and porosity of the specimens based on SEM images. On the other hand, using 20% natural zeolite as cement replacement increased surface (using Wenner probes) and bulk chloride ion penetration by 36 and 78%, respectively. Based on these results, silica fume and natural zeolite replacement are impressive tools to reinforce greywater-made green concrete so that it can properly rival and even replace regular concrete even when using more polluted greywater. Furthermore, these replacements can be great potential alternatives to wastewater dilution or treatments. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluates the suitability of construction and demolition waste (CDW) and a preselected plant palette for removing contaminants from light gray water (LGW) in nature-based solutions. Methods: One-liter containers were packed with one of the following types of CDW: concrete aggregates (CAs), crushed permeable pavement (CPP), crushed recycled bricks (CRBs), or crushed recycled tiles (CRTs) as well as a soil layer on top of each type of CDW. Containers were planted with vascular plants (Portulaca grandiflora, Chrysopogon zizanioides, Tradescantia pallida, or Nephrolepis obliterata). Plant-free controls were also prepared for each type of CDW. The containers were fed once a week for eight weeks with real LGW, and the effluents were collected to analyze turbidity, electrical conductivity, pH, ammonia nitrogen, phosphates, and chemical oxygen demand (COD). Results: CDW correctly supports the growth of the tested vascular plants and removes the analyzed pollutants in the following order of efficiency: CAs > CPP > CRBs > CRTs. The quality of effluents treated with CAs improved significantly with each tested plant, especially C. zizanioides; this combination removed 32% turbidity, 38% ammonia nitrogen, 33% phosphates, and 34% COD. Conclusions: CAs and C. zizanioides are promising elements for nature-based solutions such as rain gardens, bioswales, or green walls aimed to treat LGW. However, the leaching of electric conductivity from CDW, the proportion at which soil and CDW are added, and a more significant hydraulic retention time than the one used in this study must be considered to improve LGW treatment. [ABSTRACT FROM AUTHOR]

Abstract This study evaluated the efficiency of an on-site household greywater treatment system for indirect human reuse and for domestic lawn irrigation. This helps in the reduction in the disparity between water demand and supply that is facing the rapidly increasing global populace. Natural household greywater was settled and then conventionally filtered by using two types of non-woven geotextile media; thermally bonded and needle punched. A third woven cotton textile media was also experimented and all the non-woven geotextile media were tested in single and double layers and combined with the woven cotton textile layer. The different filter media configurations were tested for a period of one year operation (six runs) with two filtration rates of 15.00 and 25.00 m3/m2/day for each run. For all runs, the final treated effluent was disinfected using calcium hypochlorite prior to reuse. The double layer needle punched non-woven geotextile media together with the woven cotton textile media gave the best removal efficiencies; 96.34 ± 1.85% for turbidity 81.87 ± 6.43% for BOD5, 97.49 ± 1.68% for TSS, 75.35 ± 3.99% for CODt, 99.59% for E.coli. The soluble CODs removal efficiencies were negligible (below 3%) in the first four runs with non-woven geotextile media and increased to 28.05 ± 4.29% when the woven cotton textile media was added. In general, the system was found to save about 63% of the daily water consumption reflecting a net 22.50% reduction in the daily water billing costs for the whole household.

Water scarcity presents a pressing challenge in Egypt, exacerbated by factors such as population growth, urbanization, and climate change impacts. With over 95% reliance on the Nile River for freshwater supply, Egypt's water resources are strained, particularly with a population exceeding 100 million. Egypt's arid climate intensifies water scarcity, necessitating sustainable management strategies. This study explored greywater treatment as a solution to alleviate water scarcity in Egypt, investigating its technical feasibility, economic viability, and environmental benefits. Greywater, derived from domestic activities, is an underutilized resource that can be reclaimed and treated for reuse, reducing demand for freshwater sources. Through greywater treatment systems, households and communities can recycle water, conserve resources, and mitigate pollution. The study investigated using polymers as a coagulant in greywater treatment, examining its efficacy in removing contaminants and improving water quality. Experimental trials were conducted to evaluate the performance of polymer addition in greywater treatment compared to conventional methods. Results demonstrate that polymer addition reduces turbidity, suspended solids, and organic pollutants in greywater. Poly aluminum chloride (PAC) polymer, in particular, exhibits strong coagulation capabilities, versatility across pH ranges, and high efficiency in contaminant removal. Additionally, PAC offers operational advantages such as low dosage requirements and reduced sludge production.

In rural areas grappling with recurring water scarcity during dry periods, the imperative for water conservation becomes evident. This research centers on Green Infrastructure (GI), showcasing its substantial potential for better water management practices, specifically in the realms of rainwater harvesting and greywater treatment. We implemented an integrated household-scale rainwater harvesting system (RWH) coupled with greywater processing using a constructed wetland (CW). The constructed wetland, filled with sands and gravels and adorned with Napier grass (Pennisetum purpureum), served as a filtration medium for both greywater and rainwater before channelling them into a fishpond. The project was conducted at the ITB research station in Haurngombong village, Pamulihan sub-district, Sumedang, West Java. The project exemplified an effective synergy between the RWH system and a constructed wetland for greywater treatment, benefiting both plant irrigation and fishpond utilization. The demonstrated approach holds significant potential added value for communities, serving as a reservoir for crop irrigation, supporting fish farming, and facilitating greywater treatment through an integrated aquaponic system.

As Jordan advances in an attempt to promote greywater reuse, it is important to investigate the composition of bacteria in these new sources. To evaluate the presence of enteric pathogens in greywater, a pilot study investigating enteric pathogens in household washing machines and kitchen sink effluents from residential premises was conducted. In the culture-dependent method, bacteria were identified after using Sanger sequencing of 16S rRNA. Bacteria in the phylum Proteobacteria have been found to be the most abundant phyla, which may indicate that they play an important environmental role and might be representative of adaptation to different environments. Klebsiella sp. and Pseudomonas sp. were the two major genera found in this study and accounted for 78.57% of the total isolates. This is the first investigation of enteric pathogens in household washing machines and kitchen sink effluents in Jordan. To my knowledge, no study has identified the microbial hazards associated with greywater reuse in Jordan yet. Additional research with more adequate methodology is needed to assist our findings.

Although environmental groups have declaimed the application of greywater to alleviate water consumption, the progress of condensed water implementation for high-rise buildings was still sluggish. As greywater demands wastewater treatment before any application, the novelty of this study was to demonstrate the direct use of condensed water in an existing cooling water system without wastewater treatment. Considering there is barely any practical case study research to unveil the water-energy nexus in reclaiming condensed water for evaporative cooling tower systems, this research has signified that condensed water is a simple and low-budget application for water conservation and energy saving. Given that the condensed water possesses an intrinsic impurity-free property, the water-saving potentials have been amplified to the most tolerable total dissolved solids (TDS) of system water. Furthermore, it is beneficial that water quality control ameliorated the operating working conditions, the system performances were improved, and then less power was consumed. By getting rid of the wastewater treatment, consolidating the feasibility of practical direct-use application, and its sustainability for water and energy saving, this research may revive the attention of green building claimers to expedite its implementation and tie in the green building design. The condensed water derived from the electric ventilation system was reclaimed as an alternative water source for cooling without extra power consumption, which was ideal for concentration dilution and beneficial to descaling. An evaporative cooling system consumes tons of water, and the water losses are necessarily compensated by fresh water; this process occurs gradually over time and progressively escalates the TDS with time, which evocates water scale formations. Although the bleed-off (BO) that discharges the impurity-laden system water effectively lowers the TDS, it is not a water conservation measure, and the chemical effluent poses environmental hazards. The higher cycles of concentration (CoC) reduce the frequency of BO and sustain the full efficacy of antiscaling chemicals. Whenever water scales appear as a resistance of heat transfer deposit on the heat exchangers, the heat management capability is diminished and energy efficiency drops. The water and energy saving enhancement method was accomplished by reclaiming the condensed water and setting higher CoC. [ABSTRACT FROM AUTHOR]

The prevalence and antibiotic resistance of Salmonella spp. and Staphylococcus spp. from greywater were investigated in Africa’s Sahel region, Burkina Faso. A total of 36 and 56 isolates of Salmonella spp. and Staphylococcus spp. were isolated from greywater, respectively. From the Salmonella spp. isolates, resistance was most frequently observed against vancomycin (69%), ampicillin (61%), cefoxitin (42%), trimethoprine/sulfamethoxazole (36%), amoxicillin-clavunal acid (33%) and tetracycline (33%). For all Staphylococcus spp. isolates, the highest rate of resistance was against penicillin (55.36%) followed by oxacillin (48.21%) and clindamycin (30.36%). In addition, 75% of the isolated Salmonella spp. strains were resistant to at least two antibiotics of different families, while 30.35% of Staphylococcus spp. strains were multidrug-resistant (MDR). Overall, this is one of the first studies reporting the presence of MDR bacteria in untreated greywater discharged from domestic activities in Burkina Faso. Our results show that untreated greywater can contain bacteria resistant to antibiotics used in therapeutic care. Therefore, uncontrolled discharge of untreated greywater into the environment could lead to the dissemination of resistant bacteria and resistance genes in the environment and increase the risk of human exposure to antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Copyright of Soil Management & Sustainable Production is the property of Gorgan University of Agricultural Sciences & Natural Resources 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.)

As Jordan advances in an attempt to promote greywater reuse, it is important to investigate the composition of bacteria in these new sources. To evaluate the presence of enteric pathogens in greywater, a pilot study investigating enteric pathogens in household washing machines and kitchen sink effluents from residential premises was conducted. In the culture-dependent method, bacteria were identified after using Sanger sequencing of 16S rRNA. Bacteria in the phylum Proteobacteria have been found to be the most abundant phyla, which may indicate that they play an important environmental role and might be representative of adaptation to different environments. Klebsiella sp. and Pseudomonas sp. were the two major genera found in this study and accounted for 78.57% of the total isolates. This is the first investigation of enteric pathogens in household washing machines and kitchen sink effluents in Jordan. To my knowledge no study has identified the microbial hazards associated with greywater reuse in Jordan yet. Additional research with more adequate methodology is needed to assist our findings. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the financial feasibility of rainwater harvesting and greywater reuse in a multifamily building located in Florianópolis, Brazil. A building, consisting of two blocks with 60 flats each, was chosen to obtain data about the number of residents, building characteristics, potable water consumption, and rainwater and greywater demands (obtained by means of questionnaires and water measurements). The financial feasibility analyses considered rainwater and greywater systems separately and together. The impact on the urban stormwater drainage system was evaluated through the reduction of stormwater runoff. The energy consumption in the operational phase of each system was estimated through the amount of energy consumed by the motor pumps to supply one cubic meter of water. The potential for potable water savings through the use of rainwater—that supplies water for washing machines—was approximately 6.9%. The potential for potable water savings through the use of greywater—that supplies water to toilets—was approximately 5.7%. Both systems were feasible. The payback period for rainwater harvesting systems ranged from 57 to 76 months. For greywater systems, the payback period ranged from 127 to 159 months. When considering both systems working together, the payback period ranged from 89 to 132 months. The rainwater harvesting system can reduce 11.8% the stormwater volume destined to the urban stormwater drainage system in relation to the current contribution volume. Energy consumption was approximately 0.56 kWh/m3 of treated water for the rainwater harvesting system and 0.89 kWh/m3 of treated water for the greywater system. Rainwater and greywater were considered economically feasible, especially for higher inflation scenarios. Furthermore, such systems are interesting alternatives in terms of impacts considering urban drainage and energy consumption. [ABSTRACT FROM AUTHOR]

In recent decades, microalgae have been increasingly used to generate healthy food supplements and high-value products such as polyunsaturated fatty acids, pigments, and bioactive compounds. They are also being used for bioremediation of agro-industrial wastewater and as a source of energy-rich biofuels. This article provides a critical review of the available state-of-the-art for understanding the possibility of integrated greywater treatment and microalgal lipid and other energy/non-energy resource production. Integrated greywater management through microalgae cultivation is gaining attention due to its sustainability and eco-friendliness. Greywater is mainly generated from household activities and contains fewer suspended solids than normal wastewater. Microalgal biomass produced using greywater has been found to be useful for extraction of energy-rich materials and other products like bioplastics, biofertilizers, and biofuels. For example, extracted lipid can be used to generate biodiesel. Integration of all these techniques would provide an amazing greywater management plan that would produce clean water and lipid- and other essential biomolecules-rich microalgal biomass for high-value product production. However, the major constraints to industrial application of this approach include finding the most promising microalgal strains, changes in the overall composition of greywater, large capital expenditure costs, complex downstream processing, and uncertainties associated with stable revenue generation. [ABSTRACT FROM AUTHOR]

The discharge of wastewater into ground and surface waters can cause human and ecological health problems, hence eco-friendly, sustainable and cost-effective methods for removing toxic metals from wastewater are required. The study employed coconut husk biochar and spent impra ginseng flavoured green tea to adsorb cadmium (Cd), chromium (Cr) and lead (Pb) from greywater. The adsorption capacity of coconut husk biochar ranged from 88.70 % to 98.20 % for cadmium, 78 %–96 % for chromium and 95.71 %–99.29 % for lead whilst the spent impra ginseng flavoured green tea ranged from 94.03 % to 96.87 % for cadmium, 52 %–74 % for chromium and 98.52 %–99.48 % for lead. The maximum adsorption capacity (Qe) of coconut husk biochar ranged from 235.64 to 1132.40 mg/g for Cd, 1.31–8.80 mg/g for Cr and 58.85–415.80 mg/g for Pb. Lead demonstrated the highest affinity for the binding of coconut husk biochar and spent impra ginseng flavoured green tea adsorbent with a trend of Pb > Cd > Cr. Coconut husk biochar and spent impra ginseng flavoured green tea adsorbent were suitable for the toxic metals adsorption in the greywater. Cr showed different removal efficiencies where coconut husk biochar showed more effective removal than spent impra ginseng flavoured green tea. The application of coconut husk biochar and spent impra ginseng flavoured green tea in wastewater treatment is a green technology means and can lead to zero pollution of freshwater.

The management of greywater and sanitation in South Africa's urban informal settlements is a pressing concern. This review critically examines the legal framework that governs greywater management in South Africa's informal settlements, aiming to shed light on the existing regulations, gaps, and opportunities for sustainable greywater reuse. By scrutinizing the legal framework, the review identifies gaps and challenges in the regulatory environment, including inconsistencies, lack of clarity, and limited enforcement mechanisms. It explores the potential for international best practices to inform possible amendments to the existing legal framework. This was a quantitative research design utilizing a cross sectional survey model. Questionnaires were administered electronically to a sample of 17 municipal leaders from the City of Tshwane, City of Johannesburg and Buffalo City municipalities whose responsibilities were on water management. Descriptive statistics were employed in analysis of the data. Outcomes were reviewed against the alignment or the lack thereof with the SANS 1732:201x standards. This paper underscores the critical need for a coherent and robust legal framework to support responsible greywater management in South Africa's informal settlements. The paper's insights contribute to the ongoing discourse on water governance, shedding light on the pathways toward a more equitable water future. HIGHLIGHT This review critically examines the legal framework that governs greywater management in South Africa's informal settlements, aiming to shed light on the existing regulations, gaps, and opportunities for sustainable greywater reuse. By scrutinizing the legal framework, the review identifies gaps and challenges in the regulatory environment, including inconsistencies, lack of clarity, and limited enforcement mechanisms.;

Source-separated sanitation and greywater treatment have become an increasingly attractive alternative to traditional wastewater management systems in recent years due to their potential to combat water scarcity, ease resource recovery, and meet tightening effluent demands. In Helsingborg, Sweden, source-separated wastewater from the new city district of Oceanhamnen is being collected and treated in a new treatment plant (RecoLab) to test, among other issues, how efficient greywater treatment can be in achieving low discharge limits for pollutants. The greywater treatment consists of activated sludge treatment, drum filter micro-sieving, and nanofiltration. In the first two years of operation, the robustness of the treatment system during periods with extreme conditions, e.g., very low and very high organic matter concentrations, was tested. The combination of biological treatment and nanofiltration has achieved stable effluent concentrations below 10 mg/L chemical oxygen demand, 2 mg/L total nitrogen, and 0.2 mg/L total phosphorus as average values for 22 months of operation with an average flow of 43 m3/day. The treatment system for greywater treatment thus shows the possibility to achieve low discharge limits and meet the new proposed effluent demands of the EU Urban Wastewater Treatment Directive. HIGHLIGHTS Effluent greywater concentrations below 10 mg/L chemical oxygen demand, 2 mg/L N-tot, and 0.2 mg/L P-tot can be achieved without chemical precipitation.; Nitrogen speciation in greywater indicates a relatively large portion of organically bound nitrogen.; A 10 μm drum filter is adequate pretreatment for nanofiltration.;

The management of greywater and sanitation in South Africa's urban informal settlements is a pressing concern. This review critically examines the legal framework that governs greywater management in South Africa's informal settlements, aiming to shed light on the existing regulations, gaps, and opportunities for sustainable greywater reuse. By scrutinizing the legal framework, the review identifies gaps and challenges in the regulatory environment, including inconsistencies, lack of clarity, and limited enforcement mechanisms. It explores the potential for international best practices to inform possible amendments to the existing legal framework. This was a quantitative research design utilizing a cross sectional survey model. Questionnaires were administered electronically to a sample of 17 municipal leaders from the City of Tshwane, City of Johannesburg and Buffalo City municipalities whose responsibilities were on water management. Descriptive statistics were employed in analysis of the data. Outcomes were reviewed against the alignment or the lack thereof with the SANS 1732:201x standards. This paper underscores the critical need for a coherent and robust legal framework to support responsible greywater management in South Africa's informal settlements. The paper's insights contribute to the ongoing discourse on water governance, shedding light on the pathways toward a more equitable water future. [ABSTRACT FROM AUTHOR]

EGYPT is recently facing the challenge of water scarcity due to the increase in population and limitation of water resources. Therefore, researchers should investigate the usage of nonconventional water sources, for example, greywater to increase water budget which is available to overcome this problem. Since quantities of water are consumed in the ablution process, and this water is less polluted, this research aims to collect greywater and study its quality for reuse in irrigating zucchini plants. Three treatments were carried out for irrigation: 1- Tap water (TP: control), 2- Greywater (GW), and 3- Magnetized greywater (MGW). To investigate how well these treatments worked, some measurements were made on zucchini plants and soil properties. The tenth (10th) and twentieth (20th) day following the agriculture produced the maximum chlorophyll a (Chl-a), chlorophyll b (Chl-b) and carotenoid (Car) levels as compared to control when plants were watered with MGW. Additionally, the activity of antioxidant enzymes raised when GW is used, whereas it diminishes when MGW is used, compared to control on the 10th and 20th day after agriculture .The outcomes data demonstrated that MGW irrigation of zucchini plants produced the greatest NPK values. Among different irrigation water used (TP, GW and MGW), MGW recorded the most significant values of soil chemical properties as well as seed germination. The data showed that the EC value of soil irrigated by MGW significantly decreased compared to the EC values of the soil before irrigation or soil irrigated by GW or TP. Also, the germination percentage was recorded 100% after 12 days with MAW compared with TP and AW which recorded 80% for the two qualities, respectively. [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]

Since Tacna is a hyper-arid region, greywater is a potential alternative water source. This study aimed to quantify and characterize greywater in a university building with 732 students, as well as assess their perception of greywater reuse. Water meters were used to calculate greywater quantity. To assess untreated greywater quality, physical–chemical and microbiological parameters were analyzed. Questionnaires were used to measure students' acceptance regarding greywater reuse using a Likert scale. The greywater quantity recorded in this study was 426.85 L/d, which is less than reported in previous global research. The greywater quality showed relatively low values regarding physical–chemical parameters; however, microbial contamination was higher compared to international permissible limits for wastewater reuse. Furthermore, it was found that the generated greywater has little biodegradability (0.38). Students disclosed a lower acceptance of reusing untreated greywater compared to a 77.05% acceptance of reusing treated greywater for green areas. According to the greywater characterization, biological treatment will not be enough to ensure environmental protection and user health; thus, physical–chemical treatment will also be needed. The produced greywater quantities would generate a 12.67% water saving if used for toilet flushing. The greywater volume fulfills the whole demand for watering green areas or green roofs. Students would assent to the reuse of treated greywater. [ABSTRACT FROM AUTHOR]

This paper presents reclamation of greywater using "Green-wall treatment system". A Green-wall of capacity 100 L/d has been implemented with the aim of greywater reclamation from a bathing water facility. The treatment system comprised of a degreasing tank of size 0.9 m x 0.9 m x 0.3 m for oil & grease removal, followed by a Green-wall. Removal of oil & grease has been done along with commonly observed pollutants in greywater, to prevent clogging of filler material. In stage-I studies, Green-wall pots are filled with 4-10 mm Ø inert filler material LECA and in stage-II, LECA is mixed with locally available coconut peat in equal proportion. Stage-I studies using LECA indicated that maximum achievable HRT is 12 h and the treated greywater with respect to BOD does not comply with USEPA (2012) norms for landscape irrigation. In stage-II, the optimized performance is observed at 16 &18 h HRT at hydraulic loading rate 67-70 L/m²/d, when compared with 14 and 12 h HRT. Treated greywater quality met the prescribed permissible limits with respect to BOD, TSS and FC and is observed to be innocuous in terms of the reuse options for agriculture and landscape irrigation. In stage-II, the BOD, COD, TSS and FC reduce from 48 to 10 mg/L, 58 to 18 mg/L, 96 to 10 mg/L and 400 CFU/ 100 mL to below detectable limits, respectively, at 18 h HRT. [ABSTRACT FROM AUTHOR]

Faced with increasing water scarcity, the potential of greywater reuse stands out, but requires effective treatment of to remove organic matter, pathogens, surfactants, and suspended solids. Constructed Wetlands (CW) are sustainable and decentralized technologies gaining increasing prominence for this propose. They are recognized for their low-cost, simplicity, and effectiveness in wastewater treatment, producing effluents that meet quality standards for reuse. Despite their advantages, there is a need for a deeper understanding of the factors that influence their performance and efficiency. This review aims to fill this gap by systematically analyzing the current research on CW technology, identifying key variables that affect its application and potential for improvement. A systematic review considering the period 2019–2023 was carried out using Methodi Ordinatio, a multicriteria decision-making methodology. The search databases were Science direct, Web of science and Scopus. This approach involves structures process for selecting scientific articles, resulting in a bibliographic portfolio of recent studies,. The initial search yielded 291 retrieved titles, and through multicriteria selection, 48 studies were chosen for in-depth analysis. Existing studies allowed to evaluate the ways in which CW systems are applied. The review highlights how CW systems are applied, the influence of substrates type, plants, and operational criteria which emerged as the primary factors influencing the technology's performance. This review also highlights the growing use of construction waste and biochar as substrates, which have shown promise in enhancing CW efficiency. Despite the focus on greywater ''reuse'', for articles selection, it was observed that the topic was scarcely addressed, thus suggesting that studies on CW application for greywater water reuse remains underexplored. This review provides a state-of-the-art synthesis of CW technology, offering valuable insights into how specific design and operational choices impact system effectiveness. It serves as a worthwhile resource for enhancing the efficiency and application of CW in sustainable wastewater management.

Rural communities in Jordan face challenges in providing centralized wastewater treatment system due to high costs and dispersed populations. To address this issue, a decentralized approach is explored as an alternative to extend wastewater treatment to unserved rural areas. In this study, a decentralized wastewater treatment system was implemented in a household in Al-Kfair village, Jerash governorate, Jordan. The system consists of an Upflow Anaerobic Sludge Blanket Reactor followed by an unplanted Vertical Flow Constructed Wetland. The first reactor, with a capacity of 0.142 m3, received greywater from the household at an influent flow rate of 0.295 m3/d. The system's performance was evaluated based on removal efficiencies and compliance with Jordanian standards for reclaimed greywater reuse in irrigation. Influent and effluent samples were analyzed for various parameters, including Chemical Oxygen Demand, Biological Oxygen Demand, Total Solids, Nitrogen, Phosphorus, and Escherichia coli. Results indicated excellent treatment efficiency, with removal rates exceeding 90% for most parameters. The implementation of the decentralized wastewater treatment system for a single household amounted to $3405. The overall performance of the combined system demonstrated its potential as an effective solution for treating greywater in rural communities in Jordan.

Worldwide population growth and consumerism have elevated the water pollution problem to the top of the environmental priority list, with severe consequences for public health, particularly in agricultural countries such as India, where water scarcity is a big challenge. Hence, greywater has the potential to be one of the most sustainable options to meet the growing need for freshwater with satisfying treatment options. This study focused on the assessment of electrocoagulation coupled with the filtration and adsorption processes in continuous modes and different electrode arrangements including (Al-Fe-Al-Fe), (Fe-Al-Fe-Al), (Al-Al-Al-Al) and (Fe-Fe-Fe-Fe) to investigate the effect of specific flow rates (i.e., 0.05 and 0.1 liters per minute) on the removal efficiency. The findings show that a 0.05 lit/min flow rate produces a higher removal efficiency approximately between 85 to 90% with an energy consumption of between 0.5 to 4.75 KWh/m3 as compared to the 75 to 85% removal efficiency and 0.4 to 4 KWh/m3 energy consumption at a flow rate of 0.1 lit/min. The operational cost is variable and mainly depends upon the energy consumption; moreover, it was found that the optimal results and economy variation shown by the electrode assembly of Al-Fe-Al-Fe was between 20 to 22 Indian rupees at a 24 volt current density and in each combination of electrodes.

The United Nations indicates that available freshwater resources will decrease significantly due to pollution growth and urbanization; two-thirds of the world's population may face water shortages by 2030. Extended use of greywater is an alternative option for reducing potable water consumption in urban areas. Recently, the reuse of treated greywater for home gardens, peri-urban agriculture, and landscaping has become a widespread concern in many developing countries. This paper presents a study on a low-cost system that can perform greywater treatment for household use. This treatment system employed physical filtration by ceramic filters, quartz gravel, hollow fiber membrane, and UV disinfection. Three greywater samples collected from the kitchen, washing basins, and bathroom were investigated. The operation process determines the system's effectiveness by considering turbidity, coliform, Biochemical Oxygen Demand (BOD5), and Chemical Oxygen Demand (COD) concentration of the inlet and outlet water. As a result, high removal efficiency (i.e., >60%) could be obtained for each investigated parameter. Results also showed that grey water generated from washing basins has the highest potential for reuse since the water quality after treatment satisfies the water reuse standards for household irrigation. The findings encourage further exploration and implementation of greywater reuse practices. HIGHLIGHTS A greywater treatment system with six filter layers and a PVDF hollow fiber membrane was investigated.; The system's performance was assessed by measuring the pH, turbidity, BOD5, COD, and coliform concentration.; UV disinfection made washing basin greywater suitable for garden irrigation, meeting international standards.; An efficient and cost-effective system for greywater reuse in Southeast Asian households.;

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.

Treatment and reuse of greywater for non-potable applications especially in scarce countries is a feasible option. In this study, a simple greywater treatment system consisting of a low-cost simple multi-media filter with biological contact aeration system was developed and installed in a selected household in Muscat, the capital of Oman. Monitoring and measurements were made to investigate the productivity and efficiency of this system in treating the greywater from laundry and shower sources. The greywater from the collected laundry and shower contained 360 mg/L of COD and 28.5 mg/L of BOD. The experimental results showed that the greywater treatment unit achieved more than 99% of turbidity removal, more than 74% of BOD removal, and more than 50% of COD removal. BOD removal was primarily achieved through bacterial degradation whereas COD removal was attributed to the adsorption of organic compounds by activated carbon. The effluent quality of the treated greywater fell within the standard level and can be safely reused for various non-potable applications.

Worldwide population growth and consumerism have elevated the water pollution problem to the top of the environmental priority list, with severe consequences for public health, particularly in agricultural countries such as India, where water scarcity is a big challenge. Hence, greywater has the potential to be one of the most sustainable options to meet the growing need for freshwater with satisfying treatment options. This study focused on the assessment of electrocoagulation coupled with the filtration and adsorption processes in continuous modes and different electrode arrangements including (Al-Fe-Al-Fe), (Fe-Al-Fe-Al), (Al-Al-Al-Al) and (Fe-Fe-Fe-Fe) to investigate the effect of specific flow rates (i.e., 0.05 and 0.1 liters per minute) on the removal efficiency. The findings show that a 0.05 lit/min flow rate produces a higher removal efficiency approximately between 85 to 90% with an energy consumption of between 0.5 to 4.75 KWh/m3 as compared to the 75 to 85% removal efficiency and 0.4 to 4 KWh/m3 energy consumption at a flow rate of 0.1 lit/min. The operational cost is variable and mainly depends upon the energy consumption; moreover, it was found that the optimal results and economy variation shown by the electrode assembly of Al-Fe-Al-Fe was between 20 to 22 Indian rupees at a 24 volt current density and in each combination of electrodes. [ABSTRACT FROM AUTHOR]

Water scarcity is a global issue and finding alternative ways to meet our water needs within available resources is becoming increasingly important. Repurposing greywater for non‐potable uses, such as irrigation and car washing, can help alleviate the demand for drinking water. Greywater recycling and reuse are viable options to combat water scarcity. This study investigated the treatment of greywater using phytoremediation, specifically focusing on the effect of water hyacinth density and hydraulic retention time (HRT). An artificial neural network was used to optimize these parameters in the treatment system. The experiment spanned over 7 weeks and consisted of two phases. In phase I, different water hyacinth densities (ranging from 1.0 to 4.0 kg/m2) were tested, while phase II examined various HRTs (ranging from 12 to 48 h). The results indicated that the optimal conditions for greywater treatment were a water hyacinth density of 2 kg/m2 and an HRT of 48 h. Under these optimal conditions, the treatment system achieved high removal efficiencies for turbidity (98.02 ± 0.75%), chemical oxygen demand (59.42 ± 5.64%), ammonium‐nitrogen (87.45 ± 7.29%), and phosphate (94.50 ± 2.19%). However, the removal of total suspended solids was relatively low at 43.98 ± 9.20%. These findings were confirmed using an artificial neural network, showing a strong correlation (R > 0.99). The study concludes that phytoremediation using water hyacinth can be a viable option for greywater recycling and reuse, effectively addressing water scarcity. The recommended optimal conditions include a water hyacinth density of 2 kg/m2 and an HRT of 48 h. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Indonesian Civil & Environmental Engineering / Jurnal Teknik Sipil & Lingkungan is the property of IPB University 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.)

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]

Treatment and reuse of greywater for non-potable applications especially in scarce countries is a feasible option. In this study, a simple greywater treatment system consisting of a low-cost simple multi-media filter with biological contact aeration system was developed and installed in a selected household in Muscat, the capital of Oman. Monitoring and measurements were made to investigate the productivity and efficiency of this system in treating the greywater from laundry and shower sources. The greywater from the collected laundry and shower contained 360 mg/L of COD and 28.5 mg/L of BOD. The experimental results showed that the greywater treatment unit achieved more than 99% of turbidity removal, more than 74% of BOD removal, and more than 50% of COD removal. BOD removal was primarily achieved through bacterial degradation whereas COD removal was attributed to the adsorption of organic compounds by activated carbon. The effluent quality of the treated greywater fell within the standard level and can be safely reused for various non-potable applications. [ABSTRACT FROM AUTHOR]

Greywater management in Ghana has yet to receive the needed attention even though its current generation and reuse practices pose severe environmental and public health concerns, including odour nuisance, groundwater pollution, and risks from pathogens. This study examined the current greywater generation and reuse patterns among low-income urban residents in Kumasi, Ghana. Data were collected from three communities (Ayeduase, Kotei, and Twumduase) through cluster sampling, and a total of 458 questionnaires were administered to households. The average amount of greywater generated for various activities in low-income urban settlements was 53.7 l/c/d. The results showed that greywater reuse is not common among the study participants, but those who reuse it prefer laundry to kitchen and bathroom greywater. The proportion of greywater reuse was estimated at 20.1%, with 2.6, 0.9, and 17.9% of households reusing greywater from the kitchen, bathroom, and laundry, respectively. Factors that significantly influenced greywater reuse included age, the community of residence, and the type of house. The study suggests that increased education and awareness about greywater treatment, reuse, and impacts in low-income urban communities could lead to increased participation in its management. HIGHLIGHTS The average amount of greywater generated in low-income urban settlements is determined.; Data for planning are available.; Factors influencing greywater reuse are determined.; Community members have become aware of the opportunities for greywater reuse.; Education needed for the implementation of greywater treatment and management systems.;

Potable water scarcity is a global issue. Recent and ongoing droughts in the Western United States make residential water conservation crucial. Several water agencies have invested in conservation programs that educate residents on non-traditional water sources, such as laundry-to-landscape (L2L) greywater systems, which reuse washing machine water for outdoor irrigation. This study analyzed landscape vegetation and 21 greywater characteristics of 30 households with L2L systems in Santa Clara County, California. Greywater from most residential systems, even ones decades-old and unmaintained, had acceptable reuse values for major water quality parameters tested. Overall, 89% of fecal coliform counts fell within the acceptable range for water reuse, although counts were higher in non-code-compliant systems than in code-compliant L2L systems. The mean values for coliform counts, electrical conductivity, total dissolved solids, total organic carbon, magnesium, sodium, chloride, and sodium adsorption ratio were lower than the means previously reported for L2L systems. Analysis of water samples indicated high levels of iron and calcium, which merits further investigation. Outdoor vegetation appeared diverse and healthy. The promising results here indicate a high potential for expanding L2L programs. Wider system adoption can diversify regional water supply in service areas where the residential sector accounts for significant water use. HIGHLIGHTS Samples from systems compliant with California Plumbing Code had lower fecal coliform levels, and most chemical characteristics were in the acceptable reuse range for outdoor irrigation.; Homeowners did not typically change their landscaping after installing greywater systems.; Laundry to landscape programs provide an additional tool for water agencies to diversify regional water supply portfolios and conserve potable water.;

Interest in wastewater recycling as an alternative source has grown as a result of increased water demand, water shortage due to population increase, low rainfall, and economic and environmental issues. Water recycling from greywater can serve as a sustainable solution for water demands. Nowadays, membrane bioreactor systems have significantly improved treatment performance and have been widely used in water reuse and reclamation. However, optimization of the MBR system in greywater treatment has received less attention. In this context, an experimental investigation of the MBR for greywater reuse was considered to identify the optimal hydraulic retention time of the MBR system. The lab-scale MBR consisted of a bioreactor with a net volume of 10 L, containing one submerged polypropylene hollow fiber membrane module with an area of 0.2 m2. The lab-scale MBR was fed with greywater collected from a dormitory of Shiraz University and operated for 160 days. Four HRTs (3, 5, 7 and 9 h) were tested to investigate the performance of the MBR system on the removal of total ammonia nitrogen, organic matter, turbidity, and total suspended solid. The results showed that the MBR system could remove more than 95% of COD, 99.5% of BOD5, 99% TAN, and 99.2% of TSS from greywater. The COD, BOD5, TSS effluents, and turbidity were below 10.5 mg/L, 0.4 mg/L, 0.6 mg/L, and 0.3 NTU, respectively. The results also showed that the optimal HRT of the MBR system for greywater treatment was 3 h. In conclusion, the MBR system with optimal HRT of 3 h is highly efficient for greywater treatment and it could produce sustainable water for non-potable reuse such as toilet flushing reuse in terms of chemical–physical quality parameters.

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.

Untreated surfactant-rich greywater is uncontrollably discharged into the environment in underdeveloped countries and even in some areas of developing countries, which may change soil characteristics. However, there is hardly any research concerning geotechnical behavior of soils contaminated by surfactant. The present study investigates mechanical properties of two types of surfactant-contaminated sandy soils experimentally. Soil samples were collected from Bam County and Shahriar County located in the central parts of Iran. The clean specimens were contaminated by a series of prepared surfactant-rich aqueous solutions containing different amounts of a widely used detergent. The weight ratio of detergent to water was selected equal to 1/20, 1/15, 1/10, and 1/5. Physical characteristics of the contaminant solutions were examined by performing surface tension and viscosity tests. Additionally, geotechnical behavior of the clean and the contaminated samples was investigated through conducting compaction and direct shear tests. Results indicated that the geotechnical properties of the contaminated soils declined by increasing the surfactant concentration in the contaminant. Compared to clean specimens and at the highest contamination level, the optimum water content of both Bam and Shahriar soils reduced from 7.70% and 11.00% to 4.05% and 6.75% as well as the maximum density decreased from 17.87 kN/m3 and 18.52 kN/m3 to 17.37 kN/m3 and 17.88 kN/m3, respectively. Moreover, Bam and Shahriar soils with a maximum degree of contamination showed a reduction in the friction angle from 23.06° and 20.52° to 10.52° and 12.17° as well as a decrease in the formed apparent cohesion of the unsaturated samples by near 56% and 78%, respectively. [ABSTRACT FROM AUTHOR]

In this study, simultaneous nitrification and denitrification-sequencing batch reactor (SND-SBR) process was investigated to treat greywater. The effect of three process parameters, including hydraulic retention time (HRT), volumetric exchange ratio (VER) and sludge retention time (SRT), was optimised using a 23 full factorial design. The statistic model was developed for two response variables, i.e. chemical oxygen demand (COD) and ammonia (NH3-N) removal. The optimum conditions were 6.8 h HRT (anaerobic/aerobic/anoxic: 1.77 h/2.77 h/2.27 h), 0.7 VER and 7.94 d SRT, which resulted in 93.9% COD and 84.6% NH3-N removal efficiency. SRT was the most significant factor, followed by HRT and VER for COD and NH3-N removal. The interaction effect of VER and SRT was significant in COD removal. On the other hand, the interaction effects of HRT-VER and HRT-SRT were significant in NH3-N removal. The removal efficiencies of 89.6 ± 1.1% and 83.7 ± 2.3% were observed for TKN and TN, respectively, in the optimised SND-SBR system. NH3-N removal was obtained via nitrate pathway in the SND-SBR system. The PO43--P removal of 74.2 ± 3.4% was obtained via aerobic phosphorus uptake and post anoxic denitrification at the optimal condition. To enhance PO43--P removal, adsorption (using corn cob adsorbent) was integrated with SBR by adding the optimum adsorbent dose (0.5 g/L). The PO43--P removal efficiency in the SBR-adsorption system was found to be 80 ± 1.5%. The biodegradation of emerging contaminants (ECs) was also carried out in the SND-SBR system, and the results showed removal rate of 58.9 ± 2.3% benzophenone-3 (BP) and 80.1 ± 2.2% anionic surfactant (AS). [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]

The aim of the paper was to identify factors that influence the public perception of the possibility of replacing tap water with rainwater or greywater. In order to check whether a geographical location and water resources of a region affect the public's attitude toward alternative water systems, the surveys were carried out among respondents from twelve countries. The surveys identified the level of awareness among respondents about their country's water resources, ways to save water at home, and their attitudes to rainwater and greywater as additional sources of water in a building. The results showed that only 39% of respondents would not be afraid to use treated greywater in their household. The situation was better in case of replacement of tap water with rainwater, where more than 54% of the respondents were not concerned. The use of alternative sources of water for body washing and cleaning works was the biggest concern among the respondents. In case of greywater recycling, this was indicated by 56% (personal hygiene) and 34% (cleaning works) of respondents. People in the countries with low water resources view alternative water sources more favourably. They are also more aware of, and more likely to accept the use of rainwater or greywater even in uses where they will come into contact with the human body. The research also showed that for more than 3/4 of respondents, funding to install these systems would encourage their use in their household. [ABSTRACT FROM AUTHOR]

The potential for recovering heat from wastewater exists at various stages, including generation, transport, and treatment. As a result, various technologies for thermal energy recovery from wastewater are now successfully employed in many countries. In order to synthetically present the current state of knowledge on heat recovery from wastewater, a bibliometric analysis of previously published studies indexed in the Web of Science database was performed. The review was further extended with strategic SWOT and SOAR analyses to identify internal and external factors determining the competitive advantage and weaknesses related to the use of wastewater heat exchangers and heat pumps. These analyses indicated the need for further research on the possibilities of heat recovery from wastewater as the use of this technology, both at the building level and on a larger scale, contributes to the implementation of sustainable development goals, especially in terms of improving energy efficiency and reducing CO2 emissions. Particular emphasis should be placed on research into the use of warm wastewater together with other, better known and accepted, renewable energy sources. It is also important to continuously educate the public and promote heat recovery technologies at various levels, as well as to increase the involvement of legislators and other stakeholders. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of temperatures (meso-thermophilic range) on the removal of chemical oxygen demand (COD), fat oil and grease (FOG) and caffeine, and volatile fatty acids (VFA) production in acidogenic biotreatment of a mixed wastewater from toilets and a coffee shop. The mixed wastewater was prepared from 90% of toilet wastewater and 10% of coffee shop's greywater. A series of batch acidogenesis experiments in treating the mixed wastewater was conducted under mesophilic (30 and 40 °C) and thermophilic (50 and 60 °C) conditions. The results found that temperatures of 30–60 °C could remove total chemical oxygen demand (TCOD) about 30–80%, while the FOG removal efficiencies were 70–80% at the temperatures of 30–50 °C. The highest total VFA production was achieved at the temperature of 40 °C, which could be further biodegraded into biogas by the methanogenesis reactions. The initial caffeine concentrations of the mixed wastewater were about 0.6–0.7 mg/L and the results revealed that these concentrations did not change much during the meso-thermophilic acidogenic biotreatment. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the financial feasibility of rainwater harvesting and greywater reuse in a multifamily building located in Florianópolis, Brazil. A building, consisting of two blocks with 60 flats each, was chosen to obtain data about the number of residents, building characteristics, potable water consumption, and rainwater and greywater demands (obtained by means of questionnaires and water measurements). The financial feasibility analyses considered rainwater and greywater systems separately and together. The impact on the urban stormwater drainage system was evaluated through the reduction of stormwater runoff. The energy consumption in the operational phase of each system was estimated through the amount of energy consumed by the motor pumps to supply one cubic meter of water. The potential for potable water savings through the use of rainwater—that supplies water for washing machines—was approximately 6.9%. The potential for potable water savings through the use of greywater—that supplies water to toilets—was approximately 5.7%. Both systems were feasible. The payback period for rainwater harvesting systems ranged from 57 to 76 months. For greywater systems, the payback period ranged from 127 to 159 months. When considering both systems working together, the payback period ranged from 89 to 132 months. The rainwater harvesting system can reduce 11.8% the stormwater volume destined to the urban stormwater drainage system in relation to the current contribution volume. Energy consumption was approximately 0.56 kWh/m3 of treated water for the rainwater harvesting system and 0.89 kWh/m3 of treated water for the greywater system. Rainwater and greywater were considered economically feasible, especially for higher inflation scenarios. Furthermore, such systems are interesting alternatives in terms of impacts considering urban drainage and energy consumption.

The on-site use of greywater is increasingly popular for alleviating water stress in various parts of the world, particularly as a water source for irrigation. However, greywater can contain a range of pathogenic bacteria that may compromise public health as well as substances with the potential to induce environmental consequences, such as soil hydrophobicity, accumulation of salts, and damage to plants. While the health issues are being addressed by greywater legislation, its environmental risks are largely ignored. Therefore, the main objective of the current study was to quantify the impacts of greywater irrigation on soils by developing a soil quality index (SQI) using a 14-month planter experiment. The sum of the absolute value of all indicator scores represents the final score of the integrated SQI, which ranges from 0 to 100. Three threshold values were used: 70 represents optimal quality. The results based on the planter experiment revealed that, after 14 months, the SQI of all raw greywater-irrigated soils was lower than 70, indicating soil functions and plant health might be compromised. The use of scoring functions was a useful tool for quantifying and comparing the effects of greywater irrigation on different soil quality indicators. Integration of all indicator scores into a single SQI quantifies and summarizes the overall beneficial and detrimental effects of greywater irrigation. However, for better understanding and management decisions, SQI scores should be used and interpreted in conjunction with the scores of the single indicators constituting the index. In our experiment, treated ​greywater ​did ​not compromise ​soil quality even after 14 months of irrigation. As such, based on the fact that irrigation with raw greywater might compromise soil quality, treatinggreywater prior to its use is recommended.