Potable Reuse Of Wastewater Research Articles

Prediction of water reuse potential in South African water management areas: A linear regression and Bayesian network approach

Increasing scarcity of freshwater resources and growing environmental awareness have given rise to the use of treated wastewater as an additional source of water supply. However, the amount of wastewater that can be reclaimed for reuse is subject to many factors, ranging from technical to socio-economic, environmental and institutional. This paper presents two prediction models for wastewater reuse potential in South Africa. The proposed models, namely a Bayesian Network model and a Linear Regression model, were used as a platform for integrated analysis of features such as water use, and socio-demographic and environmental factors. A dataset from the sub-regions of the 19 water management areas in South Africa was employed as input into the models in order to analyse these features and to consequently predict water reuse potential.

Effluent quality and reuse potential of urban wastewater treated with aerobic-anoxic system: A practical illustration for environmental contamination and human health risk assessment

The agricultural sector requires a large volume of water (∼70 % of global water), which makes this sector difficult to produce enough food for the rapidly growing population demand with the existing scarce available freshwater source. As a viable alternative water source, urban wastewater reuse is a potential candidate. However, wastewater reuse and disposal before treatment pose a significant threat to human health and ecological systems. This study was aimed to treat urban wastewater using aerobic-anoxic system and then effluent evaluated to grow different vegetables. Wastewater samples collected (Arba Minch town) at nine sites during different seasons were used to characterized water quality (physicochemical and biological) parameters and feed aerobic-anoxic reactors. Health risk as a result of vegetable ingestion was investigated using HRI, THQ, and HI. Statistically significant (p < 0.05) seasonal variation results were observed for temperature, NH4-N, NO2-N, and sodium adsorption ratio. The performance of aerobic-anoxic treatment for COD, BOD5, TSS, NH4-N, TN, and TP was 91−94, 92−95, >96, 92, 88, and 58 %, respectively. The order of heavy metals concentration in raw wastewater was Fe > Pb > Zn > Mn > Cu > Cd, which is lower than corresponding heavy metals in vegetables having the order Fe > Mn > Zn > Pb > Cu > Cd. The phytotoxicity effect was significantly higher for cabbage followed by lettuce and tomato. The HRI, THQ, and HI values for Cd and Pb >1.0 (exceeded WHO and FAO limits) for vegetables irrigated with wastewater, which could result in health risk in adults and children. Overall, results confirmed that wastewater after aerobic-anoxic treatment is a sustainable approach to maintain safe environmental and human health.

Correction to: Assessment of wastewater reuse potential for irrigation in rural semi-arid areas: the case study of Punitaqui, Chile

In this mentioned article, the Author names are mistakenly have been replaced with the family name of the authors, and so the family names with the names.

Assessment of wastewater reuse potential for irrigation in rural semi-arid areas: the case study of Punitaqui, Chile

Wastewater reuse in agriculture has been identified as an adaptive solution to climate change. This practice copes with two of the most limiting factors that are affecting sustainable development in rural areas: the lack of sanitation services and water shortages. This paper proposes a multi-criteria methodological approach to evaluate wastewater reuse potential for irrigation in rural areas and to select the most sustainable and context-aware wastewater treatment technology. In order to validate the procedure, an empirical application for the Coquimbo region (Chile) was developed. The water balance conducted illustrated that the potential wastewater source can only partially substitute for the water canonical sources. According to local citizen preferences, among the three evaluated, the most sustainable wastewater treatment technology option consists of septic tank and constructed wetland. This study provides evidence for the relevance of integrating social and environmental criteria, in addition to technical and economic ones, for supporting decision-making processes related to wastewater reuse.

A modelling approach to assess wastewater reuse potential for Delhi city

Abstract Water availability is facing crisis throughout the world because of various factors viz., population growth, climate change, and rapid urbanization, leading to the requirement of treated wastewater as an additional source of water supply. However, the actual amount of wastewater that may be reused depends on many factors such as water demand, availability, cost and social acceptability, etc. In this study, a linear programming model has been developed to identify the amount of treated wastewater that may be used for various applications subject to water availability and demand constraints, taking Delhi city as a case study. The results suggest that wastewater reuse has the maximum potential in agriculture and landscape irrigation use followed by domestic and industrial applications. The framework developed in the study provides useful information for integrated planning and management of the reuse of wastewater in order to augment the existing water supply. It may be modified and used for the estimation of wastewater reuse potential in other areas with similar conditions.

Atrazine Removal from Municipal Wastewater Using a Membrane Bioreactor.

As the demand for potable water increases, direct potable reuse of wastewater is an attractive alternative method to produce potable water. However, implementation of such a process will require the removal of emerging contaminants which could accumulate in the drinking water supply. Here, the removal of atrazine, a commonly used herbicide, has been investigated. Using real and synthetic wastewater, as well as sludge from two wastewater treatment facilities in the United States in Norman, Oklahoma and Fayetteville, Arkansas, atrazine removal has been investigated. Our results indicate that about 20% of the atrazine is removed by adsorption onto the particulate matter present. Significant biodegradation of atrazine was only observed under aerobic conditions for sludge from Norman, Oklahoma. Next-generation sequencing of the activated sludge revealed the abundance of Noncardiac with known atrazine degradation pathways in the Norman aerobic sludge, which is believed to be responsible for atrazine biodegradation in our study. The detection of these bacteria could also be used to determine the likelihood of biodegradation of atrazine for a given wastewater treatment facility.

Transformation of N-Methylamine Drugs during Wastewater Ozonation: Formation of Nitromethane, an Efficient Precursor to Halonitromethanes.

Potable reuse of wastewater is expanding, and ozonation for water reuse is becoming more common, either as a preoxidant before membranes or as part of ozone/biological activated carbon (O3/BAC) systems. However, previous research has demonstrated that ozone drastically increases the formation potential of genotoxic halonitromethanes (HNMs), including during O3/BAC. Chloropicrin, the most common HNM, is synthesized by chlorinating nitromethane, suggesting that nitromethane may be the immediate precursor of chloropicrin, although nitromethane is unlikely to occur naturally in wastewater. We hypothesized that wastewater ozonation forms nitromethane, which would be the key intermediate toward HNMs. Ozonation of wastewater effluent was shown to form abundant nitromethane, which explained the majority (in one case, all) of subsequent chloropicrin formation. Next, we investigated a suspected category of nitromethane precursor: stimulant drugs, such as ephedrine and methamphetamine, and certain antidepressants. These drugs all feature N-methylamine functional groups, and certain N-alkylamines have been shown to produce primary nitroalkanes upon ozonation. Ozonation of N-methylamine drugs ubiquitously formed nitromethane, typically at >50% yield. Subsequent chlorination converted nitromethane to chloropicrin. The reaction mechanism was investigated to understand the variation in nitromethane yield between different precursors. These results suggest that nitromethane fate during reuse and nitromethane control should be investigated.

The potential of wastewater reuse in the Arab region as a management option for water security under climate change condition

The potential of wastewater reuse in the Arab region as a management option for water security under climate change condition

AVALIAÇÃO DO POTENCIAL DE REUSO DE EFLUENTES DE ETE EM ÁREAS IRRIGADAS DA BACIA HIDROGRÁFICA PIANCÓ-PIRANHAS-AÇU COM VISTAS A UNIVERSALIZAÇÃO

A Bacia Hidrográfica Piancó-Piranhas-Açu (PPA) abrange uma área total de 43.683 km² (ANA, 2016), com baixas precipitações, resultando em secas hídricas. O reuso de efluentes pode ser visto como uma prática que combate e minimiza os impactos sofridos pelas secas severas. Assim, uma vez que a região possui baixo atendimento ao tratamento de esgoto, neste trabalho, foi realizada uma avaliação do futuro potencial de reuso de efluentes de ETEs em áreas irrigadas. Assim, observou-se que, em relação à projeção para implantação das ETEs, em 2035, serão 131 ETEs em operação, com uma vazão total de 1,41 m3/s. A demanda de água para a agricultura irrigada na bacia é de 17,48 m³/s e com isso a oferta da água de reuso pode representar 8% da demanda de água para irrigação, a um custo estimado de transporte variando entre R$ 2,46/m3 e R$ 12,62/m3, em função do estado (PB e RN) e das distâncias de transporte (10 a 50 km). Comparando o custo da água de reuso com o valor do consumo da água bruta, constatou-se que os valores médios praticados atualmente para consumo de água na irrigação (0,02 R$/m3) inviabilizam financeiramente a prática e não se alinham com os objetivos instituídos pela lei das águas, já que os valores cobrados são ínfimos. Por fim, ficou ainda mais evidente a necessidade em se atingir a universalização do esgotamento sanitário, não somente para minimizar a poluição dos corpos d’água, mas também em propiciar efluentes tratados para a prática de reuso.&#x0D; &#x0D;

Cross-cultural Knowledge and Acceptance of Wastewater Reclamation and Reuse Processes across Select Sites

Water is in a constant state of circulation and reuse. Most reuse is unplanned, suggesting significant potential for planned reuse. Yet, attempts to implement planned potable reuse of wastewater have often been countered by public resistance. Based mostly on analyses from high-income countries, scholars have argued that educating people on the technical processes of wastewater reuse will lead to increased public acceptance. Our research explores the relationship between knowledge of wastewater treatment technology and acceptance of direct potable wastewater reuse and examines the perspectives of residents of lower and middle countries in context with, and in comparison to, residents of wealthier countries. Using data collected through semi-structured interviews with residents in community sites in Guatemala, Fiji, New Zealand, and Spain, our analysis highlights how little knowledge of wastewater treatment technology exists and that such knowledge has little bearing on wastewater reuse acceptability. Rather, cultural factors like trust are likely key. We propose that efforts to increase acceptance of potable wastewater reuse needs to be focused on explicitly cultural factors like trust more so than public education in the strict sense.

Reuse of olive mill wastewater as a bioflocculant for water treatment processes

This study investigates the reuse potential of olive mill wastewater (OMW) high in tannin content and whose complete treatment requires the use of complex and expensive processes. Tannins from OMW could serve as bioflocculant compounds according to the literature. The defatted OMW is tested in a coagulation-flocculation process on synthetic water, and the best turbidity removal rate derived is: 92% ± 1% at pH 11 for 100 mg L−1. Water-solubilized material at pH 11 precipitates after acidification at pH 6. This precipitate fraction (PP), solubilized at pH 11, is found to contain more active constituents with a turbidity removal rate of 82% ± 2% for a 60 mg L−1 dose yet reveals an increase in absorbance at 254 nm. This increase in absorbance can be corrected by using lime for a pH adjustment to 11 with an absorbance removal at 254 nm of 50% ± 1%. The bioflocculant material is characterized by means of physicochemical methods. Acid-base titration, enzymatic treatment and colorimetric dosage all confirm that tannins and/or flavonoids and cellulose constitute the active groups involved in the coagulation-flocculation process.

Background Antibiotic Resistance and Microbial Communities Dominate Effects of Advanced Purified Water Recharge to an Urban Aquifer

The growing need for potable reuse of wastewater has led to significant development and implementation of advanced treatment processes. However, the emergence of new safety concerns (e.g., antibiot...

Effect of temperature on toxicity and biodegradability of dissolved organic nitrogen formed during hydrothermal liquefaction of biomass

This study investigated the nutrient content and reuse potential of wastewater generated during hydrothermal liquefaction of microalgal biomass. The hydrothermal liquefaction reaction was tested at 270, 300, 330, and 345 °C to determine the effect of temperature on the formation of non-biodegradable dissolved organic nitrogen (nbDON). Total nitrogen, ammonium, color, and toxicity were selected as key characteristics for the reuse of hydrothermal liquefaction wastewater. Results indicated that a higher concentration of nbDON5 (nbDON defined with a 5 day growth assay) and more diverse heterocyclic N-containing organic compounds were associated with greater toxicity as measured by a growth rate assay. For the tested temperature ranges, the total nitrogen content of the hydrothermal liquefaction wastewater slightly decreased from 5020 ± 690 mg L−1 to 4160 ± 120 mg L−1, but the % nbDON5 fraction increased from 57 ± 3 %DON to 96 ± 5 %DON. The temperature of hydrothermal liquefaction reactions can be optimized to maximize carbon conversion and nitrogen recovery.

Investigation into Micropollutant Removal from Wastewaters by a Membrane Bioreactor.

Direct potable reuse of wastewater is attractive as the demand for potable water increases. However, the presence of organic micropollutants in industrial and domestic wastewater is a major health and environmental concern. Conventional wastewater treatment processes are not designed to remove these compounds. Further many of these emerging pollutants are not regulated. Membrane bioreactor based biological wastewater treatment has recently become a preferred method for treating municipal and other industrial wastewaters. Here the removal of five selected micropollutants representing different classes of emerging micropollutants has been investigated using a membrane bioreactor. Acetaminophen, amoxicillin, atrazine, estrone, and triclosan were spiked into wastewaters obtained from a local wastewater treatment facility prior to introduction to the membrane bioreactor containing both anoxic and aerobic tanks. Removal of these compounds by adsorption and biological degradation was determined for both the anoxic and aerobic processes. The removal as a function of operating time was investigated. The results obtained here suggest that removal may be related to the chemical structure of the micropollutants.

Evaluation of Enhanced Ozone-Biologically Active Filtration Treatment for the Removal of 1,4-Dioxane and Disinfection Byproduct Precursors from Wastewater Effluent.

Ozonation followed by biologically active filtration (BAF) (O3-BAF) treatment has become an alternative to reverse osmosis in potable wastewater reuse applications because of the ability to produce a high-quality effluent while reducing brine production and disposal. In this study, effluent from a sequencing batch membrane bioreactor (SBMBR) was treated by O3-BAF at three specific ozone doses (0.5, 0.7, and 1.0 mg O3/mg DOC) and different empty bed contact times (EBCTs; 15-45 min). The reaction of O3 with granular activated carbon (GAC) (O3/GAC) to promote the formation of hydroxyl radicals (·OH) was evaluated at 1.0 mg O3/mg DOC followed by BAF at 15-45 min EBCT. The efficacy of these techniques was compared for the removal of O3 refractory 1,4-dioxane and the reduction in the formation of bromate, 35 regulated and unregulated halogenated disinfection byproducts (DBPs), and 8 N-nitrosamines after chloramination. Conventional ozonation (without the presence of GAC during ozonation) removed 6-11% of 1,4-dioxane, while BAF increased the removal to ∼25%. O3/GAC improved the removal of 1,4-dioxane to ∼40%, while BAF increased the removal to ∼50%. No bromate was detected during conventional ozonation. Although O3/GAC formed 12.5 μg/L bromate, this concentration was reduced during BAF treatment to <6.8 μg/L. Even though conventional ozonation was more effective than O3/GAC for the reduction in chloramine-reactive N-nitrosodimethylamine (NDMA) precursors, BAF treatment after either conventional or enhanced ozonation reduced NDMA formation during chloramination to <10 ng/L. O3/GAC was more effective at reducing halogenated DBP formation during postchloramination. Regardless, the reduction in halogenated DBP formation during postchloramination achieved by BAF treatment was ∼90% relative to the formation in the SBMBR effluent after either conventional or enhanced ozonation. The reduction of haloacetic acid (HAA) formation improved moderately with increasing BAF EBCT. Both O3-BAF and (O3/GAC)-BAF met regulatory levels for trihalomethanes, HAAs, NDMA, and bromate.

The relative roles of sorption and biodegradation in the removal of contaminants of emerging concern (CECs) in GAC-sand biofilters

The removal and fate of contaminants of emerging concern (CECs) in water treatment systems is of interest given the widespread occurrence of CECs in water supplies and increase in direct potable reuse of wastewater. In this study, CEC removal was investigated in pilot-scale biologically-active granular activated carbon (GAC)-sand and anthracite-sand filters under different hydraulic loading rates and influent CEC concentrations over a 15-month period. Eight of the most commonly detected compounds in a survey of CEC occurrence in drinking water were selected for this study: atenolol, atrazine, carbamazepine, fluoxetine, gemfibrozil, metolachlor, sulfamethoxazole and tris(2-chloroethyl) phosphate (TCEP). GAC-sand biofilters provided superior CEC removal for all compounds (mean removal efficiencies: 49.1–94.4%) compared to anthracite-sand biofilters (mean removal efficiencies: 0–66.1%) due to a combination of adsorption and biodegradation. Adsorption was determined to be the dominant removal mechanism for most selected CECs, except fluoxetine, which had the greatest biodegradation rate constant (0.93 ± 0.15 min−1 at 20–28 °C). The mean removal efficiency decreased by 16.5% when the loading rate increased from 2 to 4 gpm/ft2 (4.88–9.76 m/h). A significant reduction in CEC removal was observed after 100,000 bed volumes when the influent CEC concentration was low (100–200 ng/L), whereas no significant reduction was observed during spike dosing (1000–3000 ng/L). A regression analysis suggested that biodegradation rate, hydraulic loading rate, influent CEC concentration, throughput, influent dissolved organic carbon (DOC) concentration, and CEC charge are important parameters for predicting CEC removal performance in GAC-sand biofilters.

Land Tenure and Water Sources for Urban Vegetable Farmers in Asante-Mampong, Ghana

Objectives: Farmland tenure and water sources are increasingly challenging among urban vegetable farmers. The pertaining situation and wastewater reuse potential are assessed in one of well-known vegetable producing centers in Ghana. Methods/Statistical Analysis: Data was collected using structured interviews and observations in a farm-based survey with 50 selected farmers (i.e. 30% of estimated farmers) between February and March 2015. Data analyses employed descriptive statistics, one-sample t-test and Chi square goodness-of-fit test at 5% significance level. Findings: Few farmers (12%, n=6) own their farmlands, and 36% (n=18) were renting at a median cost of GHS 87.5 per acre/year (GHS 77.3±35.6), which is costlier than the expected. Sizes of farmlands were mostly 1 – 2 acres (82%, n=41, p=0.064), smaller than expected although statistically insignificant. Most farmers planted vegetables all seasons (both dry and wet) (88%, n=44), and 1 – 2 different vegetables are planted on-plot at a time by most farmers as well (86%, n=43). Farmers mostly depended on direct rains (rain fed irrigation) and rain-dependent water sources (94% to 95%). Meanwhile, awareness and willingness to practice wastewater irrigation is low, 20% (n=10) and 4% (n=2) respectively. Some cost analyses and means of family livelihood are discussed in the paper. Application/ Improvements: Vegetable farmland tenure arrangements are not the best but make farmers insecure and incur high rent. Farmers’ livelihoods are prone to rainwater source overdependence. Wastewater reuse potential must be explored. Keywords: Farmland Tenure, Ghana, Vegetable Farmers, Wastewater Reuse, Water Sources

Life cycle environmental impacts of advanced wastewater treatment techniques for removal of pharmaceuticals and personal care products (PPCPs)

Pharmaceutical and personal care products (PPCPs) are of increasing interest because of their ecotoxicological properties and environmental impacts. Wastewater treatment plants (WWTPs) are the main pathway for their release into freshwaters due to the inefficiency of conventional WWTPs in removing many of these contaminants from effluents. Therefore, different advanced effluent treatment techniques have been proposed for their treatment. However, it is not known at present how effective these treatment methods are and whether on a life cycle basis they cause other environmental impacts which may outweigh the benefits of the treatment. In an effort to provide an insight into this question, this paper considers life cycle environmental impacts of the following advanced treatment techniques aimed at reducing freshwater ecotoxicity potential of PPCPs: granular activated carbon (GAC), nanofiltration (NF), solar photo-Fenton (SPF) and ozonation. The results suggest that on average NF has the lowest impacts for 13 out of 18 categories considered. GAC is the best alternative for five impacts, including metals and water depletion, but it has the highest marine eutrophication. SPF and ozonation are the least sustainable for eight impacts, including ecotoxicity and climate change. GAC and NF are also more efficient in treating heavy metals while avoiding generation of harmful by-products during the treatment, thus being more suitable for potable reuse of wastewater. However, releasing the effluent without advanced treatment to agricultural land achieves a much higher reduction of freshwater ecotoxicity than treating it by any of the advanced treatments and releasing to the environment. Therefore, the use of advanced effluent treatment for agricultural purposes is not recommended.

Performance Evaluation of Membrane-Based Septic Tank and Its Reuse Potential for Irrigating Crops.

Membrane technology, being the most emerging wastewater treatment option, has gained substantial importance with the massive objective of the reuse potential of wastewater. Keeping this in view, the present study was conducted with the rationale to evaluate the performance efficiency of membrane-based septic tank (MBST), and its reuse perspective for irrigating crops. The septic tank was designed by submerging a woven fiber microfiltration membrane module to treat domestic wastewater. Three crops Triticum aestivum (wheat), Coriandrum sativum (coriander), and Mentha arvensis (mint) were selected to be irrigated with treated MBST effluent, untreated wastewater, and tap water (as a control) for comparative growth analysis. Two pathogenic strains, Escherichia coli and Salmonella sp. were selected as reference microbes and their translocation rate was observed in root, shoot, and leaves. Upon maturity, the roots, shoots, and leaves of the above-mentioned plants were aseptically removed for microbiological analysis. Strains were analyzed, using analytical profile index and PCR analysis. Maximum removal efficiencies for MBST in terms of chemical oxygen demand (COD), turbidity, nutrients deduction (phosphorus), and indicator bacteria (Escherichia coli) were found to be 73, 96, 48, and 88%, respectively. Significant bacterial load reduction (p < 0.001) in terms of E. coli (3.8 log CFU/100 mL) and helminths (2 eggs/L) was observed in treated water. High plant yield was observed when irrigated with treated water as compared to tap water, as minimal nutrient removal (48%) was recorded in treated water, with the germination percentage of 88.8%.

Reverse Osmosis Shifts Chloramine Speciation Causing Re-Formation of NDMA during Potable Reuse of Wastewater.

UV-based advanced oxidation processes (AOPs) effectively degrade N-nitrosodimethylamine (NDMA) passing through reverse osmosis (RO) units within advanced treatment trains for the potable reuse of municipal wastewater. However, certain utilities have observed the re-formation of NDMA after the AOP from reactions between residual chloramines and NDMA precursors in the AOP product water. Using kinetic modeling and bench-scale RO experiments, we demonstrate that the low pH in the RO permeate (∼5.5) coupled with the effective rejection of NH4+ promotes conversion of the residual monochloramine (NH2Cl) in the permeate to dichloramine (NHCl2) via the reaction: 2 NH2Cl + H+ ↔ NHCl2 + NH4+. Dichloramine is the chloramine species known to react with NDMA precursors to form NDMA. After UV/AOP, utilities generally use lime or other techniques to increase the pH of the finished water to prevent distribution system corrosion. Modeling indicated that, while the increase in pH halts dichloramine formation, it converts amine-based NDMA precursors to their more reactive, neutral forms. With modeling, and experiments at both bench-scale and field-scale, we demonstrate that reducing the time interval between RO treatment and final pH adjustment can significantly reduce NDMA re-formation by minimizing the amount of dichloramine formed prior to reaching the final target pH.