Greywater Quality Research Articles

Investigating the Appropriate Quality of Greywater for Usage in the Eco-friendly Concrete Mixing

Investigating the Appropriate Quality of Greywater for Usage in the Eco-friendly Concrete Mixing

Impact of Filtration on Grey Water Quality: A Comprehensive Analysis of Christian Hospital Taxila's Grey Water before and after Treatment

Grey water, defined as wastewater excluding toilet effluents, contains varying levels of contaminants and necessitates precise reuse strategies. This study focuses on the treatment of grey water sources with relatively lower levels of contaminants, specifically excluding those from toilets which contribute the majority of harmful substances such as chemicals, body lipids, and oils. The study evaluated the physical, chemical, and microbiological parameters of household grey water, including pH, conductivity, turbidity, and the presence of elements such as calcium, magnesium, and potassium, as well as contaminants like nitrates and sulfates. The treatment system employed consisted of multiple filtration stages using sand, coconut husk, pebbles, activated charcoal, limestone, and gravel, complemented by reverse osmosis. Results indicated significant improvements post-treatment: normalization of pH, reduced conductivity, elimination of color, and substantial reductions in major contaminants. Notably, the system achieved 100% removal of E. coli, total coliforms, and fecal coliforms. The findings underscore the effectiveness of greywater treatment in reducing water toxicity and enhancing its suitability for various applications, thereby contributing to pollution reduction and resource conservation. Such recycling initiatives can significantly address water scarcity issues and encourage sustainable water resource management.

Improved greywater quality after biofiltration with a fibre-biofilter derived from plantain pseudo stem

In this study, we addressed the prevalent issue of untreated greywater discharge into waterbodies in many developing countries, despite the associated public health risks. Our approach involved utilizing fibers extracted from plantain pseudo-stems to enhance the quality of greywater through simple biofiltration setups. Greywater sourced from the GETFund Hostel of the University of Energy and Natural Resources in Sunyani, Ghana, served as the focal point of our investigation. Through the application of this biofilter, we achieved notable reductions in two crucial parameters for assessing greywater quality: biochemical oxygen demand (BOD) and chemical oxygen demand (COD), averaging at 30.4 % and 28.67 %, respectively. Furthermore, we conducted comparative analyses between the efficacy of plantain pseudo-stem fibers and carbonized coconut shell adsorbent, both individually and in composite form as biosorbents. While certain combinations of biofilters led to slight increases in conductivity, pH, and total dissolved solids (TDS) in the treated greywater, these variations were anticipated and attributed to potential organic matter leaching during the biofiltration process. Employing Fourier-transform infrared (FT-IR) spectroscopy, we detected significant spectral changes indicative of successful organic matter removal from the greywater. Specifically, we observed an intensified phenolic hydroxyl (OH) peak at 3300 cm⁻¹, which shifted marginally to 3335 cm⁻¹ post-biofiltration. Additionally, the emergence of a carboxylic hydroxyl stretch at 2850 cm⁻¹ post-biofiltration provided strong evidence supporting the efficacy of our approach in mitigating organic contaminants in greywater.

Assessment of Greywater Reuse in a University Building in a Hyper-Arid Region: Quantity, Quality, and Social Acceptance

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.

Physical, chemical, and biological evaluation of domestic laundry greywater discharges to attract reclamation strategies and reuse applications in urban settings

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

Assessment of Biological Trickling System with Different Layers of Material for Grey Water Treatment

Greywater reuse is an attractive alternative whenever water resources are scarce because it can lower water demand and increase available water supply. This study used simple, easy-to-find treatment and purification methods to examine how gray sewage from homes could be used in agriculture. The primary motivation for reducing agricultural fertilizer consumption is financial gain. If feasible, society can achieve more acceptable economic objectives. The multimedia biofilter, a biological trickling filter, treats wastewater biologically by attaching biomass to various media. In this investigation, raw greywater was settled for two hours. The same influent was used to compare and contrast two treatment approaches. The treatment methods include an exploration of the effectiveness of two filters. The first filter comprises sand, gravel, cotton, and activated carbon filtration layers. The second contains sand, gravel, brick bat, wood chips, and rice husk filtration layers. Gray water was purified utilizing a sand filtration system (gravel and sand), along with the addition of other materials to improve the effectiveness of the treatment. These additional materials included cotton, active carbon, brick, wood chips, and rice husks. Chemical tests were performed on the graywater, and each component was identified. Overall, the sand-gravel-cotton-activated carbon filter improved greywater quality to irrigation standards by reducing organic matter. The second filter (made of sand, gravel, brick, wood chips, and rice husks) is a low-cost greywater recycling unit. But there is still room for improvement in how well these filters work with higher and changing loads and how long their materials last. As a result, most of the filter materials used were waste products generated inside homes and are said to be the least expensive and most inexpensive filters.

A field assessment of residential laundry to landscape greywater quality in the San Francisco Bay area

Abstract 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.

The Assessment Suitability of Using Greywater for Irrigation in Kirkuk Governorate – Iraq

The population of Iraqi is increasing rapidly. This has increased pressure on water supply and water management. The Kirkuk Governorate and other Governorates of Iraq are facing serious challenges in this regard. The objectives of this study included evaluating the quality of greywater that generated from residential areas in the in Kirkuk Governorate and determining the suitability of reusing it for irrigate plants without treatment. The results show concentrated pH, Ec, TDS, K, Na, Ca, Mg, and SAR (7.3, 1590, 613, 16.5, 57, 79, 19.2, 1.5) respectively were greywater samples is in Iraqi standards ranges but TSS, BOD, COD, Cl, NO3 and PO4 (103, 292, 710, 42, 89, 21.5) respectively were exceeding permissible and standard value. So, it is preferable to use this type of greywater as for irrigate plants and discharge into environment after a primary treatment.

Eliminating xenobiotics organic compounds from greywater through green synthetic nanoparticles

Xenobiotic Organic Compounds (XOCs) have been widely considered to be pollutant compounds due to their harmful impacts on aquatic life. However, there have been few rigorous studies of cutting-edge technology used to eradicate XOCs and their presence in bathroom greywater. The present review provides a comprehensive examination of current methodologies used for removing XOCs by photocatalysis of green nanoparticles. It was appeared that zinc oxide nanoparticles (ZnO NPs) have high efficiency (99%) in photocatalysis process. Green synthesis provides proven processes that do not require dangerous chemicals or expensive equipment, making photocatalysis a potential solution for the status quo. XOCs residue was decomposed, and pollutants were eliminated with varied degrees of efficiency using green synthesis ZnO nanoparticles. It is hypothesized that the utilization of photocatalysis can create a greywater treatment system capable of degrading the toxic XOCs in greywater while increasing the pace of production. Hence, this review will be beneficial in improving greywater quality and photocatalysis using green nanoparticles can be an immediate platform in solving the issue regarding the existence of XOCs in greywater in Malaysia. Researchers in the future may benefit from focusing on optimizing photocatalytic degradation using green-synthesis ZnO. It might also help with the creativity and productivity of the next generation of authoritative concerns, notably water conservation.

Quality of greywater based on economic class and generation time (a case study of Ciliwung watershed, Indonesia)

Community activities highly influence the generation of greywater, whereas community activities vary from time to time. The difference in economic class of households will also affect the lifestyle, sanitation facilities, and source of clean water used which will impact the quality of greywater. Hence, this study aimed to investigate whether differences in sampling time and economic class of households in developing countries, in particular Indonesia, will affect the quality of greywater generated. Based on laboratory analysis of greywater samples at 15 households at two different times, the results obtained were pH 5.77 - 9.52, DO 0.9 - 5.7 mg/l, COD 42 - 2190 mg/l, Ammonia 0.95 - 22.5 mg/l, and fecal coliform 1.7x102 – 1.7x107 MPN/100ml. These results were analyzed using the t-test to determine the significance of the data on greywater generation between morning and afternoon as well as differences in lower middle and higher middle-class. From this analysis, it was discovered that from each parameter there was no significant difference between the greywater quality data shown in the morning and the evening. There was a significant difference in the parameters of DO and COD between samples taken at households with lower middle and higher middle economic classes.

Evaluation of antibacterial property and greywater treatment performance using composite chitosan/graphene oxide membrane

In this study, composite chitosan/graphene oxide (CSGO) membrane was fabricated through solution casting method using chitosan (CS) and graphene oxide (GO) for its application in bathroom greywater (GW) treatment. The characteristics of CSGO membrane were also evaluated in terms of its physical and molecular structure. It was noted that the blending of hydrophilic GO into CS polymer matrix successfully improved the water flux permeation of all CSGO membrane. Low loading of GO with added porosity, 0.25CSGO(II) has significant improvement in water flux permeation of 23.43 kg/m2h at 4 bars as compared to CS only 2.82 kg/m2h due to the presence of GO that improved the membrane hydrophilicity and permeability. Besides that, composite CSGO membrane has excellent GW treatment efficiency compared to CS membrane where additional 18% chemical oxygen demand (COD) removal was observed in 0.25CSGO(II) membrane. In addition, all CSGO membranes produced treated GW quality of pH 6–9.5, turbidity<5NTU, TSS<10 mg/L and non-detectable level of pathogen. The findings in this study set as a pioneer breakthrough with potential application of composite CSGO membrane in producing excellent treated GW quality that meets the reuse standard for non-potable applications.

Water reclamation techniques – A review

Water scarcity is a significant issue the world faces, as freshwater reserves are limited and geographically constrained. Water reclamation can significantly reduce the freshwater inlet and decrease the water footprint. A review of different processes for the physical and biological treatment of greywater is discussed in the following paper. This process includes Aeration, Advanced Oxidation Process (AOP), and Resin-ion exchange. A comparative study based on different parameters includes Chemical Oxygen Demand (COD). The paper also gives an insight into the process and its effect on the quality of greywater.

A review of untreated household greywater quality to inform the water saving–risk trade-off in South Africa

Interest in greywater reuse is increasing in South Africa, because of the potential to supplement scarce freshwater resources in the face of increasing demand and aridity. This paper aims to inform the water saving–risk trade-off associated with residential untreated greywater use, through a statistical analysis of greywater quality results as sourced from prior South African studies. Greywater sources included in this review were the bathroom, kitchen, laundry, mixed and general residential sources. Variability in terms of each of the reported physical, chemical and microbiological constituents by source and between result sets was noted. Statistically significant differences were evident between the pH, conductivity and phosphorus values of certain sources. A risk assessment undertaken for each of the constituents revealed further variability. The constituent with the highest number of high-risk samples was total dissolved solids. The relatively high risk and negative consequences in greywater practices in terms of public health, the environment, and infrastructure, given this variability, provide insight into the trade-off with potential water savings. It is recommended that a more nuanced view of the potential potable savings associated with greywater reuse and also improved risk management is required by the user.

Sustainable ternary treatment system for greywater and potential reuse

AbstractAdopting a greywater treatment system that provides economical, effective, and sustainable treated greywater over a longer span helps to address water scarcity. The present study focuses on treating greywater generated from hostels using a floating plant treatment system (FPTS) planted with water hyacinth. The additional units, a sand filter and an activated charcoal filter, were attached in series to FPTS to improve the treated greywater quality. The treatment system was operated for 90 days with daily monitoring of influent and effluent parameters. The treatment performance was evaluated based on the removal efficiency for total suspended solids (TSS), turbidity, chemical oxygen demand (COD), ammonia, sulphate, phosphate, and faecal coliform (FC) of 74.81% ± 5.74%, 99.76% ± 0.05%, 95.70% ± 4.10%, 99.16% ± 2.08%, 48.22% ± 1.80%, and 100%, 97.27% ± 1.48%, respectively. The study showed that the system effectively treats greywater, making it suitable for non‐potable purposes on educational institution's campuses.

Treatment of domestic greywater using fly ash as an adsorbent incorporated in a slow sand filtration system

AbstractThis study investigated the use of fly ash for treatment of domestic greywater when incorporated in a small-scale slow sand filtration (SSF) system. The system was designed, constructed, and tested for treating domestic grey water for irrigation purposes. Configuration A of the system contained sand and gravel only, while configuration B contained fly ash, sand, and gravel. The greywater samples used to test the designed system were collected from the student hostels at the Copperbelt University in Zambia. Additionally, physical and chemical characterisation of the fly ash was done and all key characteristics are presented under the results and discussion section. The system that contained fly ash considerably improved the greywater quality for irrigation purposes by reducing turbidity by 95%, colour by 98%, and chloride by 49% and increasing dissolved oxygen by 33%. However, pH, total dissolved solids, and electrical conductivity were observed to be slightly higher in the treated greywater effluent. The slight increase in these parameters is suspected to have been caused by possible leaching from the the fly ash. Therefore, obtaining fly ash from sources that may not cause any increase in the said parameters in the treated effluent is recommended to maintain compliance with irrigation water quality.

Occurrence of Antibiotic-Resistant Genes and Bacteria in Household Greywater Treated in Constructed Wetlands

There is a growing body of knowledge on the persistence of antibiotic-resistant genes (ARGs) and antibiotic-resistant bacteria (ARB) in greywater and greywater treatment systems such as constructed wetlands (CWs). Our research quantified ARGs (sul1, qnrS, and blaCTXM32), class one integron (intI1), and bacterial marker (16S) in four recirculating vertical flow CWs in a small community in the Negev desert, Israel, using quantitative polymerase chain reaction (qPCR). The greywater microbial community was characterized using 16S rRNA amplicon sequencing. Results show that CWs can reduce ARG in greywater by 1–3 log, depending on the gene and the quality of the raw greywater. Community sequencing results showed that the bacterial community composition was not significantly altered after treatment and that Proteobacteria, Epsilonbacteraeota, and Bacteroidetes were the most dominant phyla before and after treatment. Pseudomonas, Citrobacter, Enterobacter, and Aeromonas were the most commonly identified genera of the extended spectrum beta lactamase (ESBL) colonies. Some of the ESBL bacteria identified have been linked to clinical infections (Acinetobacter nosocomialis, Pseudomonas fulva, Pseudomonas putida, Pseudomonas monteilii, and Roseomonas cervicalis). It is important to monitor intI1 for the potential transfer of ARGs to pathogenic bacteria.

Greywater Treatment using Pottery Waste Ceramic Filter

Most village houses in Malaysia discharged lots of significant portion of greywater into stream or drains without any treatment. This phenomenon of direct disposal of greywater into the environment caused environmental risk, especially to water body. This study aimed to assess the quality and treatment of greywater discharge using pottery waste ceramic filter (PWCF) for safe disposal. Greywater samples were collected from 27 village households located at Kampung Parit Sempadan, Parit Raja using grab sampling method. Greywater was treated by using PWCF. The effectiveness of the PWCF was optimized using different sizes (0.25, 0.60, and 1.18 mm) of ceramic filter media at different hydraulic retention times (HRT: 1, 2, and 3 h). The t-test analysis showed significant differences between greywater from the two drainage distances. The results revealed that a distance within 81–100 m was significant to the influence of gender and the number of household occupants of the greywater discharged. The results of this study highlight that PWCF reduced the concentration of COD, BOD and TSS in greywater by 99.4%, 74.3 and 100% respectively using particle size of 0.25 mm and HRT of 3 hours. Finally, it deduced that the use of PWCF was effective and can enhance the quality of greywater for safe disposal.

Characteristics and quality of gray water and the possibility of reuse for irrigation purposes from the houses of some areas of the left side of the city of Mosul

The research dealt with assessing the quality of gray water generated from houses in some areas of the left side of the city of Mosul and determining the suitability of reusing it for irrigation; for this purpose, 90 samples of gray water were collected from fifteen neighborhoods of the left side for a period of six months during the period from November 2020 to April 2021. The research aims to conduct a monthly study to assess the quality and suitability of gray water for irrigation by conducting physical, chemical, and biological tests for gray water generated from houses Where the values of E.C. ranged (751-1621) μS/cm and T.D.S. (483-684) mg/L, and pH ranged (6.3-8.2), and the concentration of sodium ions ranged between (7.8-147) mg/L as for the concentration of C.O.D. (Chemical Oxygen Demand) ranged between (69-200) mg/L While the C.O.D. values ranged between (69-200) mg /L , The S.A.R. values were between (0.18-2.98) meq/L, and the phosphate ions values ranged between (0.25-3.7) mg/L; finally, the average of fecal coliform bacteria was (0.0-4) x 105/100 ml. The study concluded that the water was classified under the category (C3-S1) high salinity - low sodium, which is suitable for irrigation of plants that are well tolerant to salinity and is suitable for use in soils that do not contain complex layers that prevent leaching because these soils will need to be washed when irrigated with this water. This study recommended diluting gray water by mixing it with fresh water and using it for irrigation.

Environmental technology and wastewater treatment: Strategies to achieve environmental sustainability

Water is the vital liquid for human subsistence and is used as a resource in various production processes. However, the degradation of the environment is being reflected in the water resources of the planet. One of the leading causes of water pollution is ineffective wastewater treatment, which results in greywater being returned to the environment without having gone through a decontamination process. Ideally, wastewater should have the lowest concentration of polluting materials to be reused and exploited in other activities, such as agriculture or the generation of renewable energy. However, in its various forms, technological progress plays a vital role in improving wastewater treatment processes, becoming a determining factor in improving greywater quality. This study examines how environmental technology contributes to wastewater improvement in 16 selected OECD countries during 2000–2019. Annualized information is used and collected from various official sources of information, subsequently processed with various econometric approaches. The results obtained show a heterogeneous behaviour in the quantiles of wastewater treatment, environmental technology and renewable energy are positively related to an increase in wastewater treatment between 0.09% - 0.20% and 3.5 e−12% - 5.74 e−12%, respectively. Based on the results obtained, the policy implications suggest promoting environmental technology to improve wastewater treatment.

AN INVESTIGATION OF GREYWATER ONSITE REUSE POTENTIAL IN AN ARID ENVIRONMENT

Wastewater originating from bathtubs, showers, hand basins, kitchen sinks, dishwashers and laundry machines is usually not as heavily polluted as toilet water and is thus given the name greywater. Greywater separation for onsite reuse has often been voiced as a viable option, particularly for areas suffering from water scarcity. Such areas include remote arid areas, such as desert cities and arid coastal zones. However, issues related to consistency in the quality and quantity of generated greywater were listed as challenges hindering the adoption of greywater reuse. Thus, the objective of this study was to characterize the different greywater sources for variations in the quality and quantity of greywater in households in the city of Al Ain, UAE over a period of 3 months. Samples were collected from 10 Households and tested for the typical water quality parameters (pH, turbidity, COD, and TDS). In addition, a questionnaire was designed to get an estimate of the greywater flow in the different households. Results indicate that the average daily greywater production was around 88 L per person per day. Even though the results of the water quality analysis for light greywater sources (laundry, showers, and hand basins) exhibited high variability, it was still suitable for direct irrigation. The quantification of greywater flow and potential water savings indicated that greywater could be sufficient for onsite reuse in non-crop irrigation in some of the households.