Micropollutant removal from effluent of conventional wastewater treatment has recently become one of the most discussed topics in the design and operation of wastewater treatment plants (WWTPs). This ...is due to the need to add a post-treatment step to the conventional processes to comply with stricter quality standards for effluents as outlined in the revised Urban Wastewater Treatment Directive (UWWTD). The adoption of on-site or decentralized greywater (GW) treatment in sustainable buildings using vertical-flow constructed wetlands (VFCWs) is a promising direction. It represents an interesting alternative for the removal of micropollutants at the source of pollution, such as personal care products (PCPs) and some pharmaceuticals which are mainly present in this wastewater fraction. Additionally, the treated greywater could be used in households' water services which do not require potable water quality, thus saving drinking water. In this context, this work compares the results of micropollutant removal from projects using VFCWs as a polishing step of WWTPs effluent, as a centralized solution, to the results from a decentralized GW treatment. The results show that VFCWs can remove the investigated micropollutants (Diclofenac and DEET) with an efficiency of >90 %, in both centralized and decentralized treatments. The admixture biochar from plant residues and from cellulose-toilet paper proved to be a promising substitute for the mineral zeolite when mixed with sand to remove PCPs from GW and, therefore, a circular economy concept can be applied to this technology.
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•On-site greywater treatment can save at least 30 % of potable water.•Vertical-flow constructed wetlands are sustainable option for greywater treatment.•Biochar produced in a circular way is suitable as supporting material in wetlands.•Personal care products can be removed by on-site greywater treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Research on greywater reuse in water stressed areas is in full swing. However, the perception of greywater reuse is one of the least researched areas in West Africa, particularly in Sahelian ...countries. This study aimed to fills a significant gap in the existing literature, which has largely ignored the specific socio-demographic contexts of developing countries in the Sahelian regions. The study involved in-depth interviews with 240 rural households and the collection of 40 greywater samples in four locations for laboratory analysis. The survey focused on greywater management and household perceptions of greywater reuse in agriculture. The analyses focused on determining the physico-chemical and microbiological parameters of greywater collected from households. The results showed that over 80% of households discharged greywater into the natural environment without prior treatment. The majority of respondents were aware that poor greywater management poses a health risk. The results also showed an association between locality, gender, education level and perceptions of poor grey water management. Respondents were willing to accept the reuse of greywater in agriculture, to consume irrigated vegetables and to install a greywater treatment system. The quality analysis showed that the grey water was not in compliance with the legal discharge limits. This study highlights that in order to promote sustainable greywater management practices within households, it is important to design effective greywater treatment systems that meet the needs of the target population. Awareness campaigns, education and training programmes on wastewater management could also be established.
•Results highlight bad greywater discharge practices in the Sahelian Region.•Social characteristic respondent’s were linked intent to valorize treated greywater•Greywater discharged by periurban households can be treated by biological processes.•This study highlights importance of designing effective greywater treatment systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Water scarcity is a major concern worldwide. Population growth, as well as the intensive use of water resources for industrial and agricultural activities, among others, have caused water stress in ...various regions of the world. Rural areas are usually more affected due to water scarcity and a lack of sanitary infrastructure. The current practices associated with urban water management have been considered inefficient to respond to these problems. In recent years, the reuse of greywater has emerged as a promising and sustainable alternative. Several pilot greywater treatment systems have been implemented in rural areas of different countries, however, studies about the environmental impacts of these decentralized systems under different scenarios are lacking. In this work, the life cycle assessment of greywater treatment systems considering several scenarios was studied. Our results showed that the decrease in environmental impacts due to the saving of drinking water is more evident when the water supply is carried out through cistern trucks. This occurs because the environmental impact of land transport of water is extremely high and represents over 89% of the global warming indicator kg CO2 eq and 96% ozone depletion kg CFC-11 eq contributions of the system. Greywater treatment systems with backwashing and solar panels as a source of energy have lower environmental impacts, reducing CO2 and CFC emissions by 50% for the maintenance phase and by 85% (CO2) and 47% (CFC) for the operation phase. Furthermore, the acquisition of solar panels was economically feasible, with a payback of 19.7 years. This analysis showed the environmental feasibility of small-scale greywater treatment systems in rural areas affected by water scarcity. Furthermore, the proposed approach has contributed to understand the impact of greywater treatment systems in rural areas, which could become a support tool to integrate greywater reuse practices in different communities.
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•A comparative LCA was performed for greywater treatment systems in rural areas.•Greywater (GW) reuse has a greater impact when water is supplied by cistern trucks.•Backwashing and solar panels reduce impacts (CO2) by 50% and 85%, respectively.•An increase in treated GW reduces CO2 emissions from 4% to 29% in cistern truck cases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Net-zero greywater (NZGW) reuse, or nearly closed-loop recycle of greywater for all original uses, can recover both water and its attendant hot-water thermal energy, while avoiding the installation ...and maintenance of a separate greywater sewer in residential areas. Such a system, if portable, could also provide wash water for remote emergency health care units. However, such greywater reuse engenders human contact with the recycled water, and hence superior treatment. The purpose of this paper is to review processes applicable to the mineralization of organics, including control of oxidative byproducts such as bromate, and maintenance of disinfection consistent with potable reuse guidelines, in NZGW systems. Specifically, TiO2-UV, UV-hydrogen peroxide, hydrogen peroxide-ozone, ozone-UV advanced oxidation processes, and UV, ozone, hydrogen peroxide, filtration, and chlorine disinfection processes were reviewed for performance, energy demand, environmental impact, and operational simplicity. Based on the literature reviewed, peroxone is the most energy-efficient process for organics mineralization. However, in portable applications where delivery of chemicals to the site is a concern, the UV-ozone process appears promising, at higher energy demand. In either case, reverse osmosis, nanofiltration, or ED may be useful in controlling the bromide precursor in make-up water, and a minor side-stream of ozone may be used to prevent microbial regrowth in the treated water. Where energy is not paramount, UV-hydrogen peroxide and UV-TiO2 can be used to mineralize organics while avoiding bromate formation, but may require a secondary process to prevent microbial regrowth. Chlorine and ozone may be useful for maintenance of disinfection residual.
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•Net-zero greywater reuse involves nearly closed-loop recycle of greywater.•Treatment in terms of organics removal and pathogen inactivation are reviewed.•Oxidative byproduct control measures are discussed.•Considerations of site specific needs are addressed.•Treatment processes are compared with each other.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Water is one of the most essential natural resource that sustains livelihoods. Freshwater consumption and demand have, spiralled over the years, due to population growth, agricultural and industrial ...intensification. Innovative water conservation techniques (greywater reuse, rainwater harvesting, seawater desalination and ground water extraction, etc.), especially in the face of climate change and climate variability are central in minimizing water shortages, hunger and poverty alleviation, as well as health challenges. Most of water conservation methods remain ineffective and have less adoption, due to associated costs, inaccessibility and technical expertise in addressing water challenges, particularly in developing countries. Greywater reuse, which approximately represents 43–70% of the total domestic wastewater volume remains as the alternative and effective source of water that can help reduce pressure on freshwater for food production and poverty alleviation in third-world countries. Great research strides have been demonstrated on greywater reuse for agricultural use, but much remains unknown with regard to adoption rates, especially in developing countries. This work provides a detailed review on greywater reuse in crop production with particular emphasis on community perceptions, challenges and opportunities, lessons from other countries and possible implications on food security. The study has demonstrated that greywater reuse is a common practice in both developed and developing nations as a coping strategy. However, it was observed that some communities remain cautious and sceptic on its use for home gardening purpose. This resource is regarded as unclean and unfit for food crop irrigation. Limited adoption rates seem to be due to limited information or awareness programs and platforms on the potential of greywater reuse as supplement for freshwater, especially in developing countries like South Africa. However, strategies i.e. installation of greywater systems, incentivising greywater use have seen a rise in the adoption greywater in developed world. There is a need to find possible ways on how strategies from developed countries can be adopted in developing countries to promote greywater reuse for home gardening purposes.
•Climate change contributes towards the reduction in the availability of water resources.•Greywater has a potential to can supplement freshwater in agriculture.•People's perceptions towards greywater play a major role in its reuse.•Greywater reuse has a potential to improve food security in arid and semi-arid third-world countries.•Some challenges associated with greywater reuse particularly on the receiving environment are still under-researched.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Greywater reuse can allow substantial improvements in the efficiency of potable water systems. However, widespread uptake of greywater reuse depends on its acceptability by the population. Previous ...studies have assessed the implementation costs of greywater reuse technology, and considered its acceptability in principle. Although cost is clearly very important in terms of adopting/installing the technology, the actual perception of greywater reuse is crucial in driving the acceptability of use and the long-term success of the technology. This study uses discrete choice models to quantify, for the first time, the preferences of different socio-economic groups for greywater of different quality (colour, odour) and for different uses inside homes. A stated choice survey that removed the influence of installation costs was developed, and implemented in Santiago, Chile. Although legislation allows greywater use in Santiago, it does not take place at any meaningful scale. Results show that, in decreasing order of preference, there is an overall acceptance for using high quality treated greywater for toilet flushing, laundry, garden irrigation, hand washing and, shower/bathtub use, but not for drinking. When the quality of appearance in terms of colour and odour gets worse, monetary incentives could be needed even for those uses that do not involve human contact. Gender, age, educational level, water expenditure level, and in particular previous knowledge about greywater reuse, are important determinants of acceptability and thus willingness to pay for greywater use; however, their importance varies according to the type of use. Our results provide important insights for understanding the conditions that would precipitate rapid and wide uptake of greywater reuse in cities, and thereby make better use of limited water resources.
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•Choice modelling analysis of potential demand for greywater reuse in Santiago.•Big differences across potential types of reuse.•Substantial variation in acceptability across socio-demographic groups.•Monetary incentives required depend on quality of greywater, use, gender, education level, water reuse background.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The need for potable water consumption in urban and suburban regions can be decreased by greywater treatment and its reuse. Utilizing natural fibers may provide sustainable solutions in addressing ...challenges related to water resource management. In this study, a fixed-film reactor was designed with Luffa cylindrica (an annually occurring fruit) as a bio-carrier. The lab-scale reactors were configured with and without Luffa cylindrica and were run for 90 days in fed-batch mode. Scanning electron microscopy (SEM) was performed to validate biofilm production over time. Monitoring COD, nitrogen, and total phosphate removal allowed for analysis of treatment effectiveness. Results demonstrated the treatment efficiency for the experimental reactor was 70.96%, 97.02%, 92.57%, and 81.20% for COD, nitrogen, phosphate, and anionic surfactant (AS), respectively. 16 s rRNA gene sequencing of bio-carrier and control greywater samples was carried out. Many bacteria known to break down anionic surfactants were observed, and microbial succession was witnessed in the control reactor vs. the experimental reactor samples. The three most prevalent genera in the experimental samples were Chlorobium, Chlorobaculum, and Terrimonas. However, it is crucial to underscore that additional research is essential to solidify our understanding in this domain, with this study laying the fundamental groundwork.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Application of recycled municipal wastewater and industrial effluents using biological treatment methods to industrial crops is an ingenious practice to ensure the combined means of adopting ...sustainable industrial crops production through sustainable freshwater management. An investigation was made to study the effects of recycled greywater treated using the extended form of Effective Microorganisms in the sewage treatment plant, over the growth, biochemical contents, yield and fiber quality of MCU7 and SVPR2 cotton cultivars, grown under experimental conditions. The efficacy of the recycled greywater treatment was compared with ground well water as control and untreated greywater as on another treatment. Improved yield of lint fiber and cotton seeds were obtained with a ginning out turn (GOT) of 71.66% and 66.1% in the SVPR2 and MCU7 cultivars, respectively, when irrigated with recycled greywater. Similarly, both the cotton cultivars, supplied with the recycled greywater was found with a significantly higher (P ≤ 0.01) stable length (SL) and fiber strength, as well as significantly higher spinning consistency index (SCI) (P ≤ 0.05) and uniformity ratio, when compared with the other two treatments. The novelty approach, adopted in the experiment therefore can be concluded using the recycled greywater to the specific cotton cultivars in water-deficit agro-climatic conditions would be beneficial to sustain the cotton production, would be in turn benefiting the industries.
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•Cotton cultivars applied with biologically recycled greywater.•Promising level of foliar biochemical content, fiber yield, quality were obtained.•Higher ginning out turn of cotton fibers obtained, by the supply of treated water.•Experimental results are recommendable for the arid zone cotton cultivation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rainwater harvesting systems (RWHS) and greywater reuse systems (GWRS) are prominent alternatives for urban water management, which contribute to improving water use efficiency and conservation. The ...evaluation of these systems has been based mainly on technical, social and financial aspects. Recently, some studies have analyzed the environmental performance of RWHS and GWRS separately, showing promising results associated with lower impacts in comparison to conventional centralized water distribution systems. However, from an environmental perspective, limited research has been done to evaluate hybrid systems that integrate RWHS and GWRS. This study aims to analyse and compare the environmental performance of a hybrid system with a centralized system in a high water consumption household located in Bucaramanga Metropolitan Area, Colombia. The Life Cycle Assessment methodology, using the GaBi software, was applied to quantify the environmental impacts of the two water system options. The implementation of the hybrid system saves about 131 m3/year of potable water, 42.5% of total potable water consumption and reduces flows to the wastewater treatment plant by 20%. The hybrid system has better environmental performance compared to the centralized system, with lower impacts observed for 12 out of the 13 midpoint impact categories considered and all 3 endpoint impact categories in the ReCiPe impact assessment method used. The operational phase causes greater environmental impacts compared to the construction phase and the processes involved in the treatment of potable water and wastewater significantly affect the environmental impacts in both water system options compared to other life cycle phases. Overall, our study confirms the environmental benefits of the hybrid system and provides evidence useful for decision-makers regarding alternative water systems. However, further study is needed to refine the input data used for some of the processes to reflect the specific context in Colombia.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The use of greywater for agricultural purposes can contribute to water conservation, the resilience of family farming food systems, and food security, especially in regions with higher water ...deficits. However, the social acceptance of this practice has been poorly evaluated systematically and hinders the implementation due to the resulting uncertainty among decision-makers and other stakeholders in the management of alternative sources of water in agriculture. This study was designed in the concept of the Attitude and the Perceived Behavioral Control to investigate the acceptance and perception of risks and benefits of the use of greywater as an alternative water resource in agriculture and the personal environmental values and beliefs (New Ecological Paradigm scale) by 300 professionals of agricultural technicians from 12 meso-regions in Minas Gerais State, Brazil. In general, the technicians showed a positive attitude toward reusing greywater in agriculture. The willingness to consume food grown with greywater was the least positive aspect (59.3%) compared to the willingness to perform the practice (87.7%) and the belief in reusing greywater as an alternative water resource (81.7%). The result indicates a great potential for using greywater as an alternative water resource for irrigating non-food crops. The environmental position of the studied public was not a decisive guarantee for a final attitude towards the use of greywater in agriculture. The study identified a clear relationship between a positive acceptance to support the development of public policies for water reuse (81.7%) and the interviewee's local contexts of water scarcity, lack of sanitation, and socioeconomic conditions. This study contributes to the discussions about water reuse in agriculture and developing public wastewater reuse policies.
•Agricultural technicians were interviewed to assess their acceptance and perception of greywater use in agriculture.•Interviewers show a positive attitude toward the use of greywater in agriculture.•Most respondents believe treatment and irrigation techniques can minimize eventual risks to human health from greywater reuse.•The interest in greywater reuse is more effective in water scarcity regions and more precarious socioeconomic situations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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