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Eco-friendly group housing emphasizes sustainability by integrating environmentally responsible design and construction practices. The existing body of research primarily centers on urban sustainability, leaving a significant gap for rural eco-housing in developing nations like India. In the present study, a multi-vector eco-housing modeling framework has been strategically developed. The framework presented in this study integrates multiple vectors such as energy, water, and waste, utilizing modern technologies like rainwater collection systems, greywater treatment plants, and efficient irrigation systems. A comprehensive survey collected data on housing type, location, type of construction material used, gender, social indicators, and livelihoods. PV Syst was used to optimally size and design solar-based net zero energy homes through data-based climatic analysis. Each household's water consumption and waste disposal were analyzed by calculating the usage/pax./day/activity and in kgs/day, respectively. Adopting solar technologies and practices, such as rainwater harvesting and waste management, led to a considerable reduction in resource consumption and environmental degradation. Eco-friendly houses promise long-term savings through efficient water management and reduced maintenance costs, fostering a healthy living environment. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The microbial fuel cell (MFC) is considered a modern technology used for treating wastewater and recovering electrical energy. In this study, a new dual technology combining MFC and a specialized biofilter was used. The anodic materials in the system were crushed graphite, either without coating (UFB-MFC) or coated with nanomaterials (nano-UFB-MFC). This biofilter served as a barrier to retain and remove turbidity and suspended solids, while also facilitating the role of bacteria in the removal of organic pollutants, phosphates, nitrates, sulfates, oil and greases. The results demonstrated that both systems exhibited high efficiency in treating kitchen wastewater, specifically greywater and dishwashing wastewater with high detergent concentrations. The removal efficiencies of COD, oil and grease, suspended solids, turbidity, nitrates, sulfates, and phosphates in first UFB-MFC were found to be 88, 95, 89, 86, 87, 75, and 94%, respectively, and in Nano-UFB-MFC were 86, 99, 95, 91, 81, 88, and 95%, respectively, with a high efficiency in recovering bioenergy reaching a value of 1.8 and 1.5 A m−3, respectively. The results of this study demonstrate the potential for developing MFC and utilizing it as a domestic system to mitigate pollution risks before discharging wastewater into the sewer network. [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]

The pressing issue of the impact of changing agricultural policies on the water, food, and energy nexus is of utmost importance in today's world. This issue is particularly critical in countries currently grappling with a severe water crisis. This work develops a national-level water, food, and energy (WFE) nexus model using a combination of system dynamics modeling (SDM) and agent-based modeling (ABM). The WFE model focuses on water resources, with agriculture being the primary user. A model agent was designed for agriculture which includes a variety of agricultural products with varying yields, blue water and greywater consumption, energy consumption, and land area under cultivation for each crop. This paper's systems dynamics model is intended for application to meet the nutritional needs of a country's population by balancing water and energy resources and consumption while maintaining food security. The model's application covers two scenarios in Iran, a country under severe water stress. The first scenario involves nutrient supply based on the current diet, while the second scenario suggests a lacto-ovo diet. The outcomes of this study reveal that both scenarios can would lead to water and energy savings. For example, the implementation of Scenario 1 and 2 can reduce the groundwater storage deficit that occurred during the five-year study period by approximately 65% and 85%, respectively. Furthermore, based on the high volume of water saved in both scenarios, the increase in the volume of greywater is deemed neither significant nor hazardous. Considering new policies of agricultural production can lead to a new balanced diet in terms of nutrients and energy, which can impact the achievement of sustainable WFE resources. The findings of this research could prove beneficial for national policymakers who seek to promote sustainable WFE resource management. [ABSTRACT FROM AUTHOR]

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

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

There are two distinct directions of agricultural development when considering only crops and livestock. They are integrated crops and livestock systems (ICLS) and separated crops and livestock systems (SCLS). When evaluating agricultural greywater footprint (GWF), nitrogen cycling and nitrogen fixation in ICLS reduce nitrogen emissions always neglected. A novel study that aims to efficiently use water and reduce water pollution in agriculture to guide investment between crops and livestock is appealing. Based on the panel data of 11 provinces in the Yangtze River Economic Zone from 2007 to 2018, we employ the slacks-based model to evaluate agricultural water use efficiency (AWUE). GWF plays an unexpected output in the model. Furthermore, we compare both AWUE and GWF between ICLS and SCLS. The results show: (i) ICLS produce approximately 4.76 million cubic meters GWF less than SCLS, 1.89% of total GWF emission of SCLS. The greywater footprint emissions of the province's unit-mass meat (GWFM) increased by an average of 26.30%. By contrast, the greywater footprint emissions of unit-mass grains (GWFG) decreased by an average of 27.37%. (ii) ICLS improves the AWUE of the province to the highest level of 10.78% compared with SCLS. (iii) If government allocates capital investment in crops and livestock freely, an additional 1% of crops investment would increase by 1.94% of GWFG while livestock could reduce GWFG by 2.12%. Investment in livestock is valid. [ABSTRACT FROM AUTHOR]

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

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

Green walls are gaining attention for greywater management in the imminent terrestrial space and land constraint scenario. They have been tested primarily with greywater from a single source such as showers, hand or wash basins, laundry, and kitchen or a mix of a couple of these sources but barely with mixed greywater from all these household activities. Here, a green wall system coupled with a slow sand filter (SSF) was tested for managing household greywater. It consisted of a set of five serial hydraulic flow-connected reactors and an SSF unit. Each reactor housed an Epipremnum aureum sapling embedded in the support bed matrix, consisting of cocopeat and granular activated charcoal. The system operated at 150 cm d−1 hydraulic loading rate (HLR) achieved 90 ± 0.7%, 85 ± 4.5%, 72.9 ± 4.4%, and 60.6 ± 5.1% removal efficiencies for turbidity, chemical oxygen demand (COD), total nitrogen (TN), and total phosphorous (TP), respectively. The system maintained similar treatment performance with varying greywater strength when COD and TN were below ~400 and ~15 mg L−1, respectively. The polished effluent produced by SSF operated at 187 cm d−1 HLR, with characteristics <5 mg L−1 COD, <2 NTU turbidity, <1 mg L−1 TN, ~0.5 mg L−1 TP, ~7.8 pH, and <100 MPN per 100 ml fecal coliforms, qualifies the standards for non-potable reuse applications. Along with reclaimed water reuse, green walls provide environmental benefits by fixing CO2 in plant biomass. Overall, the low-cost system offers efficient greywater management in an eco-friendly way with minimized resource consumption and areal footprint. [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]

To achieve Goal 6 of the 2030 Agenda for Sustainable Development and provide water for all, water reuse is essential. We assessed the potential of treating greywater (LGw) while reusing it via irrigation of Canna x generalis, commonly used in nature-based solutions (NBS), with a view on plant development. The study was conducted at a mesocosm scale with factorial designs to test two substrates and four types of irrigation water. Stage 1 tested LGw, LGw with nutrients (LGw + N), tap water (TW) and TW + N. Stage 2 tested indoor and outdoor applications of TW (TWi and TWo, respectively) and LGw (LGwi and LGwo, respectively). All treatments resulted in reductions in total nitrogen and phosphate concentrations. The effluent turbidity, chemical oxygen demand, and surfactant contents of LGw + N and LGw decreased considerably after passing through the substrate. The results showed no statistical differences among the measured variables when LGw and TW received commercial fertilizers, which provided advantageous conditions for complete plant development, as evidenced by flowering. Conversely, compared with all other treatments, LGw treatment alone resulted in inferior development and exhibited some symptoms of nutritional deficiency, observed as reductions in dry biomass in the aboveground parts (range: 1.87–6.52 g) and belowground parts (10.03–36.19 g). Overall, Canna x generalis did not exhibit symptoms of toxicity and became fully developed, except for flowering, proving to be a robust species that is resistant to adverse environmental conditions, and is therefore recommended for cultivation in nature-based systems for landscaping integrated with LGw treatment and reuse. [ABSTRACT FROM AUTHOR]

This article presents a study of Hybrid Rainwater/Greywater Systems (HRGS), with the objective of perceiving the main factors that influence their performance and how they can be optimized. For this goal, a decision support tool, that makes their dimensioning and performs an economic and performance analysis, was used for four different types of buildings: a single-family house, a multifamily building and two service buildings. For each case, distinct scenarios were defined, considering different end-uses of non-potable water, in order to evaluate the performance of the systems using effectiveness and performance indicators. Results show that the effectiveness of "non-potable water consumption" is influenced by two main factors: the final uses considered for non-potable water and the storage volume. In most of the study cases, values of effectiveness (ratio between the volume of non-potable water used and non-potable water demand for the final uses considered) greater than 50% were obtained. In the case of domestic buildings, such as single-family house and multifamily building effectiveness values above 67%, were obtained. And for the case of service buildings, the effectiveness was between 42.8 and 65.6% in one case, and between 12.9 and 93.6% for the other. The best performance of the studied hybrid systems is achieved when the volume of non-potable water used in the building is maximized, resulting in greater savings of potable water. In addition, the larger the fraction of greywater reused, the lower the volume of wastewater produced and sent directly to the sanitation network. [ABSTRACT FROM AUTHOR]

Bone char has been successfully prepared from ostrich bone waste (OBC) via the physical activation under the presents of N2 gas and then was characterized by different techniques. The utility of the mass transport (MT) model to simulate the breakthrough curves of mercury(II) in a packed-bed adsorption column was evaluated and compared with the mathematical models (Bed Depth Service Time (BDST), Adams–Bohart (AB), Thomas, Dose–Response (DR), and Yoon–Nelson (YN)) under diverse operating factors such as influent concentration (35, 75, and 150 mg L−1), inlet flow rate (5, 10, 15, and 20 mL min−1), pH (2, 5, 7, and 9), and bed depth (10 and 20 cm). Based on the modeling results, it was concluded that the MT model had the best accuracy (R2 = 99.31%, MRE = 0.745% and NRMSE = 6.15%), followed by Th, BDST, YN, DR, and AB. The sensitivity analysis showed that the simulated breakthrough curves were more sensitive to maximum adsorption capacity (qT) than axial dispersion coefficient (DL) and apparent equilibrium constant (k). All models overestimated the breakthrough curves (MRE > 0). OBC was able to eliminate the Hg(II) from the real samples (greywater and petrochemical wastewater), which indicated that the presence of organic compounds in wastewater had no effect on the mercury(II) adsorption efficiency. The overall results showed that the dissolution–precipitation process and ion-exchange reaction were involved in the adsorption of the mercury(II) by OBC. [ABSTRACT FROM AUTHOR]

Greywater is an important alternative water resource which could be treated and reused in buildings, reducing the freshwater demand in drought affected areas. For the successful implementation of this solution, it is important to ensure the microbial safety of treated greywater. This study examined the microbiological quality of treated greywater produced by an emergent nature-based technology (green roofs) and a chlorination process. Specifically, the effect of substrate, substrate depth, and vegetation on the removal of total coliforms, Escherichia coli, and enterococci in experimental green roofs treating greywater was examined for a period of about 12 months. In addition, the ability of chlorination to inactivate the abovementioned pathogen indicators was evaluated and their potential regrowth was examined. Results shown that green roofs filled with 10 cm of perlite reduce total coliform concentration by about 0.4 log units while green roofs filled with 20 cm of vermiculite reduce total coliform concentration by about 1.2 log units. In addition, the use of vegetation in green roofs improves the removal of pathogenic bacteria by about 0.5 log units in comparison with unvegetated systems. In all cases, the effluents of green roofs failed to satisfy the criteria for indoor reuse of treated greywater for non-potable uses such as toilet flushing without a disinfection process. The addition of 3 mg/L of chlorine in the effluent provided safe greywater microbiological quality for storage periods of less than 24 h, while longer periods resulted in the significant regrowth of pathogens. In contrast, a chlorination dose of 7 mg/L completely secured inactivation of pathogen indicators for periods of up to 3 days. [ABSTRACT FROM AUTHOR]

The utilization of hybrid-constructed wetland systems has recently expanded due to more rigorous municipal wastewater discharge and also complex wastewaters treated in hybrid-constructed wetlands (HCWs). A lab-scale two-stage experimental setup of vertical flow followed by horizontal flow hybrid-constructed wetland (VFHCW-HFHCW) configuration was built. First-stage vertical flow hybrid-constructed wetland reactor with the surface area was 1963.49 cm2 and second-stage horizontal flow hybrid-constructed wetland reactor with the surface area was 2025 cm2. The HCW unit was planted with two type plants: Calibanus hookeri and Canna indica (Cannaceae). Influent Municipal wastewater flow rate 112.32 l/day, hydraulic loading rate (HLR) 0.55 m/day, and hydraulic retention time of 1 day. The efficiency was evaluated in municipal wastewater quality improvement and physico-chemical analysis in our laboratory. The removal rate after the second-stage horizontal flow of BOD3 at 27 °C, COD, TSS, TP, NH3-N, and NO3-N reached 92.75%, 89.90%, 85.45%, 88.83%, 99.09%, and 96.05%, respectively. The results shown after both stage hybrid-constructed wetland VFHCW-HFHCW, treated effluent of Municipal wastewater produced high-quality effluent which may be reused in gardening, agriculture, and flushing in toilet purpose according to Bureau of Indian Standards (BIS) code for practices. However, in the future, hybrid-constructed wetlands could be standards design criteria developing and enhancing the performance standards and economic meets both to make more popular technology of the hybrid-constructed wetland (HCW). [ABSTRACT FROM AUTHOR]

The potential of source-diverted graywater reuse mainly relies on the efficiency and cost of graywater treatment technology. Oxygen (O2) supply and utilization rate directly determine the energy consumption and pollutants removal rate in the biological graywater treatment. This study developed a gravity flow self-supplying O2 and easy-to-maintain bio-enhanced granular-activated carbon dynamic biofilm reactor (BhGAC-DBfR) for on-site graywater treatment. Results showed that increasing of saturated/unsaturated ratio led to the continuous growth of biomass on GAC surface. Division of saturated and unsaturated zones favors the formation of aerobic-anoxic-anaerobic biofilm in the reactor. A saturated/unsaturated ratio of 1:1.1 achieved the maximum removal rate of chemical oxygen demand (COD), linear alkylbenzene sulfonates (LAS), ammonia nitrogen, and total nitrogen at 98.3%, 99.4%, 99.8%, and 83.5%, respectively. Key is that adsorption and biodegradation play important and distinct roles in the quick uptake and continuous removal of both organics and N in the system. The related genus and enzymes functional for LAS mineralization, deamination of organic N, ammonium oxidation, and nitrate respiration enabled the efficient and simultaneous removal of organics and N in the BhGAC-DBfR. This study offers a promising engineering alternative technology with great potential to achieve efficient and low-energy-input graywater treatment. [ABSTRACT FROM AUTHOR]

The ecological integrity of the Hassar Stream (suburban of Casablanca city, Morocco) is monitored using aquatic indicators (macroinvertebrates). In this study, monitoring water physicochemical quality reveals a high level of organic pollution and nutrients in this stream, mainly due to allochthonous inputs from Mediouna treated wastewater and greywater and solid waste from riparian settlements. In parallel, a total of 85 macrobenthic taxa belonging to three major faunistic groups (annelids, molluscs, and arthropods) were identified in this hydrosystem. The species richness and faunistic diversity increase progressively from upstream to downstream according to the organic and nutrients loads, and the mineralisation of waters. The assessment of the biological quality of the water using index methods (Belgian Biotic Index "BBI", Family Biotic Index "FBI", Iberian Biological Monitoring Working Party "IBMWP" and Iberian Average Score Per Taxon "IASPT") indicates average or acceptable quality levels. Compared to its previous bioecological condition, the improvement of the faunal diversity and the biological quality of Hassar Stream water indicates a progressive recovery of the macroinvertebrates community and its resilience despite the chronic disturbance linked to the discharge of treated water from the Mediouna wastewater treatment plant. Finally, this study shows that biotic indices can constitute a complementary approach to the taxonomic richness and faunal diversity metrics to appreciate the resilience degree of a Mediterranean disturbed stream. [ABSTRACT FROM AUTHOR]

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

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

Clean drinking water is a necessity and recycling stormwater and greywater has been more appealing in the recent decades to provide filtered water for drinking water and non-drinking water purposes. Biosand filters have been a popular filtering system of filtering potable water in developing countries, due to their simplicity in construction, reliability in operation and availability of constituent materials. The sand filtration system consists of diffuser rock, two sizes of gravel, and sand, which the container is constructed from concrete or plastic. Sand filtration system tend to struggle in removing specific chemicals such as nitrate and phosphate. Therefore, innovative materials can be added to the sand filtration system to increase the chances of chemical removal. Innovative materials such as biochar and bentonite clay were used to analyze their effectiveness in sand filtration system experiments. Biochar and bentonite clay have unique characteristics such as absorbing capacity and activated carbon, which remove suspended solids, chemicals, and toxins from contaminated water. Constant head permeability tests were used to simulate the sand filtration system in the lab. 15 tests were completed with different filter media arrangements, which incorporated two types of sand (coarse and fine), two sizes of gravel (small and large), biochar, and sodium bentonite clay. Contaminated water was created by simulating greywater by adding chemicals to reverse osmosis water. The pH, sulfate, chloride, phosphate and nitrate ion concentration removal were analyzed based on the contaminated water and filtered water. The hydraulic conductivity, filtration rate and pressure loss were also analyzed for each test. The tests that had the most effective result in terms of chemical ion removal, pH neutralization and filtration rate was the arrangement that included large and small gravel, fine and coarse sand, and biochar. [ABSTRACT FROM AUTHOR]

Optimal design and maintenance are necessary for the sustainability of wastewater treatment systems. In this study, we present the outcome of a novel approach to baseline assessment conducted prior to the design and deployment of a decentralized wastewater treatment system at a school in rural India. The baseline water quality monitoring protocol was deployed to assess (a) the quality and quantity of wastewater (greywater and blackwater) flows from the school and (b) the status of surface water and groundwater quality in the catchment. Hourly greywater flows and water quality trends were monitored across four seasons at the school. Average freshwater consumption at the school was 518 ± 322 L/day for hand washing and 287 ± 97 L/day for cooking meals. Greywater generation showed high hourly variations in COD levels. Greywater generated from hand wash and kitchen sources contributed to 110 g/day and 96 g/day of BOD5 respectively and 214 g/day and 141 g/day of COD respectively. Based on additional data from a self-reporting sanitation survey, the organic contaminant load generated from the toilet was estimated to be 1.5 ± 0.1 kg COD/day. At the catchment scale, both groundwater and surface water quality were monitored seasonally to assess the impact of raw sewage and stormwater inputs. Compared with borewells, high nitrate–N levels (> 10 mg/L) were observed in the village hand pump samples throughout the year. Maximum nitrate–N (16 mg/L) and fecal coliforms (3.9 log MPN/100 mL) levels were observed in surface waters during monsoons, indicating the impact of sewage and surface runoff on water quality. The proposed approach is useful to estimate data on freshwater use and wastewater generation at the school and hence to make the case for, and design of, a sustainable water management intervention. [ABSTRACT FROM AUTHOR]

A long-duration laboratory study spanning more than 6 months was conducted to evaluate the effect of operating mode on the performance of sand filters for greywater treatment. Performance of saturated and unsaturated filters operated in continuous or intermittent mode was evaluated using settled real greywater. Effects of pause period and higher loading rate on their performance were also evaluated. Furthermore, the effect of the depth of the filter medium on the performance of the filters was also assessed. The saturated filters operated continuously or intermittently performed significantly better than the respective unsaturated filters. Saturated continuous (SC) and unsaturated intermittent (UI) filters were the best and worst performers amongst the different filters. SC filter removed on an average 98% turbidity, 76% BOD, 88% COD, 84% ammonia-N (NH4-N) and 95% phosphate (PO4-P). Up to 99.68% (2.40 log) removal of faecal coliforms was also achieved by this filter. SC filter showed stable and reliable performance as its effluent quality was insensitive to fluctuations in influent quality. The pause period significantly affected the removal of some of the parameters. Doubling the hydraulic loading rate significantly affected the performance of continuous filters. Though most of the pollutant removal occurred in the top 10 cm in all the filters, a depth of 50 cm was found optimum for the removal of different pollutants. Whilst all the filters produced effluent conforming to different reuse standards except microbial standards, saturated continuous filter (SC) could also meet the faecal coliform standards towards the end of the filter operation. [ABSTRACT FROM AUTHOR]

Greywater constitutes a major portion of wastewater generated from domestic units. Greywater treatment through a natural treatment system provides a sustainable method of wastewater management. The objective of this study was to evaluate the potential of water hyacinth as phytoremediation aquatic microphytes for greywater treatment based on optimum growth and harvesting frequency. The treatment system was operated in continuous mode for 30 days. The physicochemical properties of treated greywater and physical characteristics of water hyacinth were determined. The physiochemical parameters of the influent greywater: water temperature (23.1–24.9 °C), pH (6.94–7.94), total dissolved solids (192–648 mg/L), turbidity (9.8–49.9 NTU), chemical oxygen demand (51.2–179.2 mg/L), ammonium–nitrogen (2.8–6.16 mg/L), and phosphate–phosphorous (0.45–1.168 mg/L). The results showed an average removal of ammonium–nitrogen, phosphate–phosphorous, and chemical oxygen demand of 63.26 ± 10.47%, 61.96 ± 12.11%, and 51.91 ± 5.32%, respectively. A 75% increase in the water hyacinth biomass was observed during the study which may be attributed to the dense roots, hyperaccumulative properties, and the rapid growth rate of water hyacinth. A harvesting interval of 15–20 days was recommended for phytoremediation of greywater for efficient treatment performance. However, feasible harvesting methods need to be developed for removing only matured mother plants, leaving baby water hyacinth in the treatment system. Water hyacinth found to be a potential phytoremediation plant for greywater treatment, providing consistent quality of treated water. [ABSTRACT FROM AUTHOR]

The degradation of three pesticides, azoxystrobin (AZO), difenoconazole (DFZ), and imidacloprid (IMD), commonly found in the tomato rinse water, was studied through UVC (251–257 nm) and UVC/H2O2 photolysis. The results showed that direct photolysis follows pseudo-first-order kinetics, with total AZO and IMD removals within 15 min, using 21.8 and 28.6 W m−2, respectively, while the highest percentage of DFZ degradation was 51.7% at 28.6 W m−2 UVC. The estimated quantum yields were 0.572, 0.028, and 0.061 mol Einstein−1 for AZO, DFZ, and IMD, respectively. With regard to UVC/H2O2, total pesticide removal was achieved after 10 min, while optimal treatment conditions in relation to the pesticide removal rates, estimated through the sequential Doehlert design, were about [H2O2]0 = 130 mg L−1 and 26 W m−2. Cytotoxicity and genotoxicity assays carried out with Allium cepa, for real industrial tomato rinse water sampled from washing belts did not show abnormalities during cell division, with total pesticides degradation after 15 min, demonstrating the potential application of the UVC/H2O2 process as a viable localized treatment with a focus on the possible reuse of treated water. [ABSTRACT FROM AUTHOR]

Reuse of modified fly ash for treatment of dye wastewaters is a promising new technology with the potential to mitigate two waste streams currently having negative effects on the environment. In the present study, cationic fly ash adsorbent was prepared by immobilizing with poly-epichlorohydrin-dimethylamine for treating reactive dye wastewaters. Characterization analyses confirmed that poly-epichlorohydrin-dimethylamine had been immobilized onto fly ash, and this immobilization could change the Zeta potential of fly ash from negative to positive throughout the range of pH from 3 to 11, but could not alter its crystal structure. Static adsorption analyses demonstrated that dye adsorption process was spontaneous and endothermic, and the experimental data were better in accord with pseudo-second-order kinetic model. Column experiments showed that cationic fly ash displayed a dramatically high dye adsorption capacity, which was over 1.5 times more than that of commercial activated carbon. Reusability study confirmed that synthesized cationic fly ash can be used repeatedly in column. Especially, in order to avoid secondary pollution, the generated disabled cationic fly ash adsorbent can be reused to produce polymer concretes as a functional filler. The present work can provide new insight into the utilization of modified fly ash for treating wastewaters. [ABSTRACT FROM AUTHOR]

A multi-objective model has been applied for optimal allocation of water from limited resources to meet increasing demands in multiple sectors. The study region is Saudi Arabia, while the time span is from 2020 to 2050 with interval of 10 years. The available water resources in Saudi Arabia are groundwater (GW), surface water (SW), desalinated water (DW) and treated wastewater (TWW), whereas the users are domestic, agricultural and industrial sectors. The goal programming technique has been used to formulate the model with multiple objectives. These objectives are (1) water demands satisfaction; (2) water quality control; (3) maximizing allocation of SW and TWW; and (4) minimizing extraction of GW, overproduction of DW and overall cost of water use. Allocations of GW, SW and DW in domestic sector are 508.4, 225.7 and 2174.2 MCM, respectively, in 2020, which are projected to be 585.3, 349.1 and 4494.8 MCM, respectively, in 2050. From 2020 to 2050, contribution of GW and SW in agricultural sector may reduce from 10,283.5 and 218.7 MCM to 8753 and 95.2 MCM, respectively, while this reduction is recovered by increasing contribution of TWW from 2291.9 in 2020 to 3945.8 MCM in 2050. During this period, contribution of GW in industrial sector shows increasing rate of approximately 171 MCM per year. Water quality is controlled through controlling the level of total dissolved solids to the standards. Production of DW and TWW has to be increased in order to meet the future needs. The total cost of using water is estimated as 13 billion US$ in 2020, which is predicted to be 22 billion US$ in 2050. This study attempted to suggest the possible scenarios to satisfy increasing water demands from limited resources in different regions of Saudi Arabia. Such scenarios can contribute in developing sustainable strategies for water resources management in water deficit regions. [ABSTRACT FROM AUTHOR]

Water scarcity in Jordan is becoming more severe with time, which resulted in an indispensable need for economic innovative approaches to maximize the utilization of nonconventional water resources through reuse options. Within the framework of the current study, a novel vertical flow constructed wetland system was implemented for greywater treatment in four different rural areas in Jordan. In this paper, the primary objective was to develop a regression-based nonlinear model to predict BOD effluent concentration from the proposed system. The model obeyed the first-order kinetics and found to provide an efficient tool in predicting the effluent BOD value as exemplified by an R2 of 0.78. Moreover, a cost analysis was carried out to verify the feasibility of the proposed system. The economic results revealed a NPV range of 295–1209 JOD (420–1730$), IRR range of 6–10.7%, and a payback period range of 8.8–15.5 years. The average calculated costs of greywater treatment using the VFCWs were found to be 0.391 (USD/m3 treated) and 0.672 (USD/kg BOD removed). Finally, the energy saving from using the proposed system was quantified and an estimate of 70 JOD (100$)/year household was obtained. [ABSTRACT FROM AUTHOR]

The presence of antimicrobials in wastewater (WW), surface water (SW), groundwater (GW), and even in potable water from treatment plants has been reported from many countries. Their presence in the water sources is causing the rise and spread of antimicrobial resistance (AMR), thereby threatening our public health, global economy, and development. This necessitates the constant monitoring of these compounds along with the evaluation of their associated risk to aquatic organisms. In this study, GW, WW, and SW samples from different parts of West Bengal (India) were analyzed using the SPE-HPLC-DAD method for detecting two frequently used fluoroquinolones (ciprofloxacin, CIP and ofloxacin, OFL). The highest concentration of CIP and OFL was 5.75 μg/L (GW) and 17.84 μg/L (WW), respectively. The antimicrobial activity was determined against Escherichia coli and Staphylococcus aureus isolates from WW against CIP, which showed that Escherichia coli and Staphylococcus aureus had developed ~ 69 and ~ 12 times resistance compared to their respective pure strains. The risk assessment showed that CIP poses an insignificant threat to fish and Daphnia (RQ < 1) but a significant threat to green algae and Microcystis aeruginosa (RQ> > 1). OFL concentration also poses a great threat to all the organisms for which the assessment was made (RQ> > 1). Moreover, risk assessment in terms of AMR showed that the present level of these antimicrobials in different water sources could cause the development of resistance among the microbial community (RQ > 1). These results emphasize the need for constant monitoring of pharmaceutical compounds, especially antimicrobials, to be kept under check. [ABSTRACT FROM AUTHOR]

The most important goal of every water distribution system is to deliver water to the consumers in the demand and time determined by its users. However, not all water usages require the potable water quality. One of the technical solutions enabling water recycling and its reuse is a dual installation system. Dual installations recycle rain wastewater or grey water from bathtubs, showers and sinks and further reuse it for irrigation or toilet flushing. The profitability of a dual installation system is highly dependent on the water price, which tends to vary significantly according to the location. The purpose of this paper is to evaluate the profitability of dual installation systems in exemplary hotel building hypothetically located in 10 different European countries. The profitability was determined on the basis of multi-criteria decision analysis performed for two installation variants. The investment was evaluated in terms of technical, economic and environmental aspects. As a result, the selected countries were ranked in order of the most profitable location for dual installation system's investment. [ABSTRACT FROM AUTHOR]

To realize the integrated remediation of SW/GW and soil in the rural river network area, the integrated remediation in rural river network area project (IR-RRNA), funded by the Ministry of Science and Technology of the People's Republic of China, has been launched. In eastern China, the rural river network area (RRNA) is an anthropic active area characterized by its rapid economic development and high gross national product. However, the water environmental pollution in these areas is increasingly severe, which has greatly hindered their sustainable development. Especially, the frequent interactions between surface/groundwater (SW–GW) have intensified the pollution migration and transformation in RRNA. The IR-RRNA (2019–2022) will apply the related interdisciplinary and methodological knowledge to elucidate the transportation and transformation of pollutants in water and soil during SW–GW interaction and develop remediation technologies of surface water, groundwater, and soil suitable for the RRNA. In this way, to realize the remediation technologies integration for surface/groundwater and soil in RRNA and implementing application demonstration. Meanwhile, a technical guideline will be compiled for the integrated remediation suitable for the RRNA. This project is conducive to addressing the urgent environmental problems as well as promoting rural economic revitalization and ecological environment optimization. [ABSTRACT FROM AUTHOR]

Eggshells (ESs), a low-cost biosorbent rich in calcium carbonate (CaCO3), were used to sustainably reduce the acidity and remove the Fe(total), Al3+, and Mn(total) ions from coal mine-impacted water (MIW). The surface area and pore volume of ES biomaterial were 5.692 m2 g−1 and 0.0567 cm3 g−1, respectively. The remediation process was performed in two consecutive stages, with Fe(total) and Al3+ ions being removed in the first stage (treatment I) and the Mn(total) ions in the second one (treatment II). The best treatment conditions, statistically determined through a central composite rotatable design (CCRD), were 6.59 g L−1 ES and 95 rpm agitation rate for treatment I and 28 g L−1 ES and 280 rpm agitation rate for treatment II. However, the high ES dosage in treatment II, determined by extrapolation, led in practice to the formation of particle aggregates that decreased the treatment efficiency. Therefore, the best values experimentally determined for treatment II were 25 g L−1 ES and 250 rpm. In these conditions, the overall treatment provided complete MIW acidity neutralization, total removal of the Fe(total) and Al3+ ions, and 58% Mn(total) ion removal, providing treated fluvial water adequate for non-potable use based on the analyzed parameters. [ABSTRACT FROM AUTHOR]

In a context of scarcity of good quality water, reuse is a mandatory practice to increase water availability, thus allowing the exploitation of more cropland. Although several studies have evaluated the hydric potential of domestic gray water to promote the economic and environmental sustainability of agriculture, the focus of this study was to evaluate the application of this effluent on an ornamental plant, the sunflower. The experiment was conducted in a protected environment using a completely randomized block design with split plots and four replicates. Irrigation solutions containing different mixtures of treated gray water effluent (TGW) and drinking water (DW) (100% DW, 25% TGW + 75% DW, 50% TGW + 50% DW, 75% TGW + 25% DW, and 100% TGW) were arranged in the plots, while the ornamental sunflower cultivars (Bonito de Outono Sortido and Sol Vermelho) were arranged in the split plots. Irrigation with treated gray water did not affect the growth of the plants and the quality of the flowers until the dilution of 55% in drinking water. The cultivar Sol Vermelho showed better plant growth and flower quality when fertigated with dilutions of treated gray water. The principle of mixing fresh with gray water, applied to the production of ornamental sunflowers, allows obtaining flowers of good quality while saving drinking water and decreasing the deposition of effluents in the environment. [ABSTRACT FROM AUTHOR]

Egypt is a country with limited water resources. Egypt water needs are growing rapidly as a result of the population increase, climate change and development activities. The aim of the study is to analyse how Egypt can sustain its mega urban projects by utilizing greywater as a non-conventional water resource. A quantitative-based assessment has been conducted to investigate the overall evaluation of the greywater resources in Egypt. Greywater accounts for between 40 and 80% of the total water discharged from the house, and the total use of water for drinking and health use can be estimated at 10.4 billion cubic meters per year. The results show that the greywater resources may support a sustainable future of non-conventional water resources in a very positive way. Greywater can provide Egypt with about 4.15–8.30 billion cubic meters annually, which is a good support for water resources in Egypt. The paper concluded that greywater is an important resource to facilitate the success of the new mega urban projects. Egypt should maximize the share of greywater resources, especially in its new mega urban projects. Greywater resources can support Egypt and other arid and semiarid regions and countries in transition to a sustainable future. [ABSTRACT FROM AUTHOR]

The reuse of wastewater is one effective approach to solving the problem of water resource scarcity. However, deterioration in the quality of reused water, such as increased odor and bacterial growth, restricts its reuse. The objectives of this study were to characterize graywater (GW) treatment technology and to verify the suitability of the reclaimed water for toilet flushing. A membrane bioreactor (MBR) and biological aerated filter (BAF) were used to treat GW in a 1-year laboratory-scale experiment. The optimal operational conditions of the MBR and BAF were as follows: hydraulic retention time = 2–3 h, dissolved oxygen = 4–7 mg/L, mixed liquor suspended solids = 3500–4500 mg/L, and contact reaction time = 1.96–5.89 h, dissolved oxygen = 3–5 mg/L, backwash cycle time = 24–48 h, respectively. The MBR treatment resulted in reductions in COD, NH3-N, and turbidity of 60–90%, 80–90%, and 95–99%, respectively, whereas those of BAF treatment were 50–90%, 50–90%, and 80–90%, respectively. The BOD5 values of MBR and BAF effluent were 1.2–4.5 mg/L and 2.5–7 mg/L, respectively. GW treated by both MBR and BAF met the standard for reusing water for toilet flushing. The effluent from MBR, BAF, and BAF + ultrafiltration treatment and purified mixed wastewater was used to simulate toilet flushing at 28 °C, with the addition of 5 mg/L NaClO to the reused water. The residual chlorine levels were 1.5, 0.6, 0.9, and 0.5 mg/L, respectively, after 15 days. No bacteria were detected in any of the reclaimed water after 15 days. The water quality of the effluent of MBR-treated GW was better than that of the mixed wastewater. The results show that it is viable to use GW purified by MBR for toilet flushing. This study provides a scientific basis for the popularization and application of reclaimed water for toilet flushing. [ABSTRACT FROM AUTHOR]

Improving water management depends on understanding the functioning of irrigation and drainage systems across different environmental scales. For this purpose, this study in the Nile Delta of Egypt particularly examines the spatial and temporal variation of drainage water salinity from the system to the plot level. A better understanding of this variation across nested scales is crucial to refine the government's drainage reuse strategy and reduce the adverse effects on agricultural productivity, lagoon ecology, and human health. The study investigates the drainage system of the Meet Yazid study area (82,740 ha) located in the upper central part of the Nile Delta. The parameters measured were electrical conductivity (EC), dissolved oxygen (DO), pH, and temperature. Results showed that salinity and quality of drainage water in the Nile Delta vary highly with space and time. The secondary drains exhibited the highest variability of salinity compared with main drains and subsurface drainage collectors because they accumulate salts from deeper soil layers and seepage of saline groundwater at the time of low flow discharge. In secondary drains, the salinity increased up to four times that of drainage water coming from the collectors. Moreover, DO values were most of the time not meeting standards for reuse in irrigation, especially at main drains that collect not only agricultural drainage but also untreated household sewage water. [ABSTRACT FROM AUTHOR]

Degradation of Rhodamine B in aqueous solution was carried out with different microplasma medium generated from air, oxygen, nitrogen and argon gases at atmospheric pressure. Rhodamine B (RhB) aqueous solution was prepared (10 ppm) and treated in microplasma reactor at different treatment time and applied potential. The RhB degradation was mainly due to the hydroxyl radical formation, during the plasma treatment, which was identified by terephthalic acid probe method. The result shows that the oxygen microplasma produced more hydroxyl radicals than air, nitrogen and argon. The degradation percentage of RhB solution with respect to different plasma gases were estimated by using UV–Vis absorption spectra which reveals that the oxygen microplasma is most competent for complete degradation within petite time followed by air, nitrogen and argon. Post discharge phenomenon was observed in air and nitrogen microplasma treated solution, which could reduce the treatment time to accomplish complete dye degradation. The sample treated with air and nitrogen microplasma for 3 min resulted in the degradation percentage of 62.3% and 60.4%, respectively, and the complete degradation was obtained after 7 and 10 h of post discharge, respectively. Further an attempt was made to verify the reusability of air microplasma treated solution as a liquid fertilizer in cultivation purpose using Mung bean (Vignaradiata). The obtained results were encouraging as the treated water enhanced the seed germination and plant growth notably. [ABSTRACT FROM AUTHOR]

In the United States of America, urban areas of the arid Southwest are prone to drought risk and changing precipitation patterns; future water supplies are uncertain. A collaborative working group of researchers and practitioners developed alternative future scenarios for 2060—sustainable water futures—that incorporate standard and novel water-adaptation strategies for the Phoenix metropolitan area (hereafter "Phoenix") in central Arizona, USA. The authors adapted WaterSim-6, a water policy and planning model, to explore differences in water demand and supply for three scenarios as influenced by (1) runoff from the rivers that supply surface water to Phoenix, (2) population growth, (3) water use efficiency, (4) annual rainfall, and (5) land-cover land-use changes. Centralized water-management strategies (direct and indirect potable water reuse and reclaimed supplies) and decentralized strategies (rainwater harvesting and greywater use) were explored. We observed decreased reliance on surface water supplies, offset by increased municipal groundwater pumping in the Strategic scenario, but by alternative water supplies (non-potable water sources including greywater, reclaimed water, and rainwater harvested) in the Desert Wetland and Almost Zero Waste (AZW) scenarios. Even under modest policy implementation and service-connection adoption rates associated with our Strategic scenario, by 2060 alternative supplies from non-potable sources could offset 30% or more of outdoor water demand. Aggressive policy implementations associated with the AZW scenario suggest that up to 80% of outdoor water demand could likewise be met. The WaterSim platform combined with co-produced future scenarios illuminates tradeoffs in support of decision making for long-term sustainability of a water-limited region. [ABSTRACT FROM AUTHOR]

Greywater has attracted global attention as a feasible alternative water source over the last few decades. Reuse and recycling of greywater is an economically viable and attractive option for meeting the future water demand. However, its treatment and reliable reuse continue to be based on conventional parameters such as BOD, COD, turbidity, suspended solids and pathogen level. The current investigative study focused on the characterization of segregated grey wastewater (greywater from bathroom, laundry and kitchen) from different economic classes of Indian households which included physical and chemical parameters, organics, nutrients, pathogens, heavy metals, oil and grease and surfactants. Apart from this, the data related to water consumption, frequency and products used for their daily activities were gathered using a questionnaire survey. The average water consumption among different household was found to be 108 L per capita per day. The maximum concentrations of organics such as BOD (678.6 ± 179 mg/L), COD (1507 ± 508 mg/L) and TOC (176.4 ± 131 mg/L) were found in kitchen wastewater. However, maximum concentrations of surfactants (14.02 ± 3.74 mg/L) were obtained in laundry wastewater. Faecal coliform concentration was more in the households which had inhabitants of children below 4 years. Statistical analysis revealed that the parameters monitored differ significantly between different economic classes. The present study showed that the characteristics of greywater highly depend on the wastewater source, household behaviour and activities. This study will be helpful to design a sustainable cost-effective treatment system, enabling greywater generated from different sources to be safely recycled and reused by households. [ABSTRACT FROM AUTHOR]

Purpose: The International Maritime Organization's (IMO) International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) was entered into force in September 2017. It deals with one of the greatest threats to coastal and marine environments around the world: aquatic invasive alien species (IAS) and harmful aquatic organisms and pathogens (HAOP). Although the control of IAS and HAOP through treatment of ballast water (BW) is appropriately dealt with in the Convention and its implementation, the problems generated by sediments are not treated in such a manner. Materials and methods: There are many published technical and scientific papers, discussions and commentaries proposing the remediation of the present situation. They are discussed, and recommendations are summarized. Besides, several systems for the treatment of BW use a combination of two or three techniques, with filtration usually being the first and/or the last step. Presence of sediments in BW results in the reduced applicability of such an approach. Results and discussion: The requirements for sediment management procedures are discussed along with a proposal for their implementation. In the first step, the ballast tank sediments should be freed of active biological agents for the elimination of IAS and HAOP. Instead of biological agents, we advocate the use of radiation treatment by using an electron accelerator, preferably in an on-shore installation or as a mobile, additive, sea container size units with integral power, separated for water and sediment treatment. In the second step, the concentrations of heavy metals should be determined. We recommend the use of EDXRF as an analytical method. After the determination of sediment class, the recommended disposal procedures should be followed. Conclusions: Sediment management procedures should specify the disposal requirements: (i) free of active biological agents, IAS and HAOP; (ii) chemical composition, no chemical elements in a toxic range (≤ Class 3); and (iii) displacement/storage requirements, displacing sediments characterized as harmful in appropriate sediment reception facilities/landfills. [ABSTRACT FROM AUTHOR]

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

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

Determining alternative water sources to meet municipal water demands is important when availability is limited. The purpose of this study was to demonstrate a means for water planners to estimate the amount of combined sanitary wastewater and storm water that they might already be capturing through open air oxidation ponds. Increased understanding of the quantity of water that is already available could help water planners to better envision optimal water reuse scenarios. Using water and climate data on oxidation ponds in these three cities within the Texas Panhandle from 2010 to 2014, we evaluated water quantities which would be available for potential reuse. From the net monthly wastewater volumes values, the study also considered if per capita demand could have been met by reusing the wastewater. The study found wastewater volumes were lower in fall and winter months and much higher in spring and summer months. If a city considers reusing wastewater, blue water (groundwater) extraction could be reduced by as low as 45–50% in one city to as high as 100% in another. Water planners in similar environments and wastewater treatment systems may find this demonstration of potential reuse water quantity encouraging for better meeting their own water demands and enhancing water supply resiliency. [ABSTRACT FROM AUTHOR]

This paper evaluates the metabolism-based performance of a number of centralised and decentralised water reuse strategies and their impact on integrated urban water systems (UWS) based on the nexus of water-energy-pollution. The performance assessment is based on a comprehensive and quantitative framework of urban water metabolism developed for integrated UWS over a long-term planning horizon. UWS performance is quantified based on the tracking down of mass balance flows/fluxes of water, energy, materials, costs, pollutants, and other environmental impacts using the WaterMet2 tool. The assessment framework is defined as a set of key performance indicators (KPIs) within the context of the water-energy-pollution nexus. The strategies comprise six decentralised water reuse configurations (greywater or domestic wastewater) and three centralised ones, all within three proportions of adoption by domestic users (i.e. 20, 50, and 100%). This methodology was demonstrated in the real-world case study of San Francisco del Rincon and Purisima del Rincon cities in Mexico. The results indicate that decentralised water reuse strategies using domestic wastewater can provide the best performance in the UWS with respect to water conservation, green house gas (GHG) emissions, and eutrophication indicators, while energy saving is almost negligible. On the other hand, centralised strategies can achieve the best performance for energy saving among the water reuse strategies. The results also show metabolism performance assessment in a complex system such as integrated UWS can reveal the magnitude of the interactions between the nexus elements (i.e. water, energy, and pollution). In addition, it can also reveal any unexpected influences of these elements that might exist between the UWS components and overall system. [ABSTRACT FROM AUTHOR]

A pilot-scale batch-flow free water surface (FWS) constructed wetland (CW) system planted with Rhynchospora corymbosa (L.) Britton was developed with a hydraulic retention time (HRT) of 2.5 days. The average porosity of the substrate was 0.55 and calculated hydraulic loading rate (HLR) was 3.96 (g BOD/m2-day). Quantitative and qualitative characterization of the greywater were done. The concentrations of pollutants in the greywater before and after it was fed into the FWS CWs were measured using standard sampling and analyses methods. The average daily per capita water use estimated was 162 L, out of which 72.5 L was greywater. The mean removal efficiencies (RE) of the CWs were 81% COD, 85% TN, 82% TK, 10% TP, 0.2% pH, 81% TSS, Zn 91%, 81% Al, 94% Mg, and 90% Fe. It was observed that the FWS with batch-flow configuration tested in the study was slightly different in terms of results reported on the conventional continuous flow system. R. corymbosa as a macrophyte has roots that can provide a surface area for microbial growth and oxygen exchange and can be used as emergent macrophytes in phytoremediation of greywater. The result provided information on the performance and pollutant removal efficiency of a batch-operated FWS CW system planted with R. corymbosa. [ABSTRACT FROM AUTHOR]

In recent years, more and more countries see irrigation using reclaimed water as an opportunity to secure and enhance agricultural production. Despite the benefits of water reuse, the scientific community raised several concerns and challenges for human health and the environment. This includes chemical risks. Effluents from urban wastewater treatment plants usually contain a wide range of organic chemicals. Such chemicals remaining in the water after the treatment process may cause hazards for human health, contaminate surrounding soil and water resources, and even compromise drinking water sources. Once crops on irrigated sites are exposed to chemicals, the potential transport to and accumulation in the edible parts of fruits and vegetables need to be controlled to rule out their introduction into the food chain. Finally, problems concerning the release of wastewater-borne antibiotics into the environment are starting to gain attention. For these reasons, agricultural irrigation should face more stringent quality requirements in order to minimize chemical risks. Combinations of measures reducing chemicals at the source, technical and natural water treatment processes especially to remove chemicals with persistent, bioaccumulative and toxic (PBT), or persistent, mobile and toxic (PMT) properties, good agricultural practices, and supplementary preventive measures (e.g. knowledge transfer to the stakeholders involved) will be necessary to bring about and ensure safe irrigation in the future. While internationally many regulations and guidelines for water reuse have successfully been implemented, questions remain whether the current knowledge regarding chemical risks is sufficiently considered in the regulatory context. The introduction of a new regulation for water reuse, as attempted in the European Union, poses a good opportunity to better take chemicals risks into account. [ABSTRACT FROM AUTHOR]

Interest in both environmental impact and potential beneficial uses of produced water (PW) has increased with growth in unconventional oil and gas production, especially in semi-arid regions, e.g. the Permian Basin, the most productive tight-oil region in the USA. Characterization of PW compositional variability is needed to evaluate environmental impact, treatment, and reuse potential. Geochemical variability of PW from Guadalupian (Middle Permian) to Ordovician formations was statistically and geostatistically evaluated in the western half of the Permian Basin (Delaware Basin, Central Basin Platform, and Northwest Shelf) using the US Geological Survey's Produced Waters Geochemical Database and the New Mexico Water and Infrastructure Data System. Mean total dissolved solids (TDS) of PW increased with depth in the Delaware Basin and Central Basin Platform to the Delaware and Wolfcamp formations (Guadalupian age). Mean TDS decreased with further increases in depth. In contrast, the mean salinity of PW was significantly higher within the shallow, younger formations (largest mean TDS in the Artesia Formation); TDS decreased with depth below Guadalupian age formations in the Northwest Shelf. Kriged contour maps of TDS and major ions illustrated spatial variability across the three geo-structural regions as a function of depth. The occurrence of meteoric waters in upper and deeper formations across the three regions was significant, and was attributed to Laramide Orogeny and Basin and Range extension uplifting and tilting effects and recent water flooding. These results quantify PW composition variability, and suggest that upon treatment, PW would support some uses such as onsite reuse and mining. [ABSTRACT FROM AUTHOR]

Samples of pruning sawdust (PS) and water treatment plant (WTP) sludge residue were collected and mixed in proportions of 10 to 80% of WTP sludge in PS, submitted to torrefaction at 260 °C, and the resulting biochar samples were submitted to TG/DTG analysis to assess their decomposition, thermal stability, and immediate analysis. Also, the nitrogen adsorption–desorption isotherm, mercury-injection capillary pressure (MICP), ultimate analysis, SEM, EDS, and FTIR were employed. The biochars of blend with 20% of sludge (BB20) and PS without sludge (BBM) were the ones that presented the best stability test in an aqueous medium. The biochar BB20 presented thermal stability (190 °C), moisture (5.7%), volatiles (48.6%), fixed carbon (35.9%), ash (9.8%), BET surface area ( 0.7942 m 2 g - 1 ), mean pore diameter ( 389.13 Å ), adsorption–desorption isotherm characteristic of the mesoporous material, highest MICP total pore volume, porosity (76.7%), total pore area ( 62.859 m 2 g - 1 ), mean pore diameter ( 0.1322 μ m ) , the predominance of macropores. The biochar BBM showed BET surface area ( 1.3366 m 2 g - 1 ), mean pore diameter ( 169.97 Å ), adsorption–desorption isotherm characteristic of mesoporous material, better second one MICP total pore volume, porosity (64.4%), total pore area ( 76.520 m 2 g ), mean pore diameter ( 0.0786 μ m ) also, macroporosity. According to the results presented, the biochar BB20 itself to several uses as substitution of anthracite coal in water and filtration systems plant for the wastewater treatment due to macroporosity and as a viable solution to the reuse of these two residues. [ABSTRACT FROM AUTHOR]

The processes of microplastic fiber pollution in groundwater are unknown. The recent research on this contaminant threat is generally focused on surface waters (mainly oceans and rivers), while aquifer contamination is only marginally mentioned as an issue needing further investigation. Synthetic microfibers can be introduced into soils in different ways (e.g. wastewater treatment plants or greywater discharge, septic tank outflows, direct injection of contaminated water in cases of managed aquifer recharge, losing streams, etc.), and can thus reach aquifer systems due to leaching or infiltration in soil pores. Microfibers can then adsorb persistent bioaccumulative and toxic chemicals, which include persistent organic pollutants and metals, and become a carrier of harmful substances in the aquifer system, hence contributing to the overall contamination in both urban and rural areas. For this reason, it is of paramount importance, not only to assess the occurrence and fate of microplastic fibers in groundwater, but also to study the role of microplastics as carriers of contaminants within the aquifer and to advance standardization and organization of monitoring campaigns. Only by addressing these key challenges can hydrogeologists contribute to the state of the art on microplastic pollution and ensure that groundwater is not neglected in the environmental assessments tackling this contaminant of emerging concern. [ABSTRACT FROM AUTHOR]