Non-potable Water Research Articles

Alternative water sources as a pragmatic approach to improving water security

This study considered a volumetric water balance to assess the influence of AWS on future water security in the City of Johannesburg. Hydrological modelling was implemented in HECHMS to quantify runoff volumes up to the year 2050, whilst a GIS-based MCDA was run to cater for socio-economic factors influencing RWH. The outputs from these analyses, together with city water balance, were integrated into WEAP to develop a decision support tool to evaluate the potential of AWS to improve water security. The RWH suitability map shows that at least 50% of the city meet the potential for RWH, whilst the hydrological simulation shows that the harvestable runoff is twice the total non-potable water requirement, demonstrating that RWH reliability can be significantly maximised with increased storage. The scenario analysis highlights that AWS can bridge the gap between water supply and demand, thereby building resilience to climate uncertainties and protecting the environment.

A review of draft Environmental Protection Agency Method 1633: A data user's perspective

AbstractCurrently, the availability of multilaboratory‐validated analytical methods for per‐ and polyfluoroalkyl substances (PFAS) is limited. Two of the more commonly known methods are the finalized United States Environmental Protection Agency (EPA) methods for the analysis of select PFAS in drinking water samples, EPA 537.1, Determination of Selected Per‐ and Polyfluorinated Alkyl Substances in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) (EPA 600‐R‐20‐006) and EPA 533, Determination of Per‐ And Polyfluoroalkyl Substances in Drinking Water by Isotope Dilution Anion Exchange Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (EPA 815‐B‐19‐020) These two methods were developed specifically for drinking water samples, which generally do not have matrix interferences and are generally an easier matrix to analyze. EPA also finalized SW‐846 Method 8327, Per‐ and Polyfluoroalkyl Substances (PFAS) by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS), which covers the analysis of select PFAS in nonpotable water matrices. However, one of the critical deficiencies in this method is the lack of the gold standard for quantitation, isotope dilution, which has become a critical necessity for the analysis of PFAS in nondrinking water matrices to accommodate for potential matrix interferences. In addition, the United States Department of Defense (DoD) Environmental Data Quality Workgroup (EDQW) has stated that SW‐846 Method 8327 should only be used as a screening method and should not be used for the collection of definitive data. The release of Draft EPA Method 1633, Analysis of Per‐and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC‐MS/MS (EPA 821‐D‐21‐001), for nonpotable water matrices, is a first step toward providing the laboratory community with a standardized method that can provide accurate results for PFAS in nonpotable water matrices.

Green/sustainable treatment of washing machine greywater for reuse in the built environment

Given the growing demand for water in the world, approaches and/or actions are needed to reduce consumption and increase demand. In the latter case, water reuse is a viable alternative to increase the demand for non-potable water in homes. This study aims to optimize washing machine greywater treatment using aqueous solutions of aluminum sulfate and Moringa oleifera seed extract. To this end, an experiment was carried out using washing machine greywater from a residence. The data from this test were evaluated adopting the Response Surface Methodology (RSM). The parameters evaluated in the experiment were the pH, turbidity, sludge volume produced, and the total dissolved solids. Afterward, these were compared with limits established by technical standards and authors regarding non-potable water reuse. The results of this study indicate that using the treatment with the lowest coagulant dosages, i.e., 20 mL L −1 of Moringa oleifera extracted in calcium nitrate and 1 mL L −1 of aluminum sulfate, it is feasible to reuse greywater after treatment in toilet bowl flushing. For these dosages of coagulants, the turbidity removal was 96.22% and the pH varied from 7.2 to 6.8. The association of aluminum sulfate with Moringa oleifera extracted in calcium nitrate is viable for the treatment by coagulation of greywater from the washing machine to reduce the dosage of each coagulant and meet the criteria of the standards. • Combining natural and chemical coagulants to treat the greywater, up to 96.22% of the turbidity was removed. • Modeling the treatment, using response surface methodology, led to optimizing and reducing the use of the chemical coagulant. • Using Moringa oleifera combined with calcium nitrate enhances the effects of the natural coagulant. • Treated water meets the criteria for reuse in toilet flushing.

“Spatial Data Analysis for Ground Water Quality Assessment With Special Reference to Fluoride” - A Case Study of Dhar District, Madhya Pradesh, India

Water is a prime natural resource and physiological necessity to mankind. Therefore, drinking water must not carry harmful chemicals as well as biological contaminants for the well-being and human health. Some of the chemicals like Fluoride, Iron, Arsenic, Cadmium, Chromium, Lead, selenium, and Nitrate in water may produce serious physiological changes when exist beyond permissible concentration.
 
 The Aim of the study was to create spatial map for drinking water purpose for Dhar district, MP. The ground water quality data were collected from PHED, M.P. and IMIS (Ministry of Drinking water & Sanitation) Website,Government of India. The GWQ layers were created  separately for each element for Pre-Monsoon and Post-Monsoon period from the well point layers with interpolation technique. Each element wise layer has been categorised into `three catagories (1) potable water in Desirable limits (2) Potable water in permissible limits (3) non-potable ground water, as per BIS standard, 2015. The Union of eight element layers of each pre-monsoon and post-monsoon has been done and integrated pre-monsoon and Integrated post-monsoon Ground Water Quality (GWQ) map have been prepared and after the Union of these two maps, the Final ground water quality map has been prepared. It was concluded from the study, that multiple parameters are affecting the quality of ground water in Dhar district and particularly excess Fluoride, Nitrate, Total Hardness (as Caco3), Iron, pH, and Total Dissolve solids are prevalent in the area. About 69.66% Habitation of Dhar district is severely affected mainly by excess of Fluoride, Nitrate & Total Hardness (as Caco3), pH & Iron(Fe) & It is observed that about 70.51% area of Dhar district has been affected in terms of Ground Water Quality.

Prospects of utilizing seawater as a reaction medium for pretreatment and saccharification of rice straw

The transition towards a bio-based economy has led to an unprecedented surge in fresh water consumption that renders biofuel a high water footprint product. The depleting fresh water resources have exacerbated the situation which necessitates the exploration of non-potable water for biorefinery purposes. In the current study, seawater is used as a plausible alternative reaction medium for pretreatment and saccharification of rice straw. Response Surface Methodology (RSM) based on Box-Behnken Design (BBD) was employed to model, predict and validate cellulose release and reducing sugar yield from rice straw subjected to microwave-NaOH pretreatment. The optimized pretreatment conditions were determined to be 8.54% substrate loading, 1.94% NaOH and 4.09 min which resulted in the maximum cellulose release of 65.43% and reducing sugar yield of 0.554 g/g. Several physico-chemical studies of the raw and pretreated biomass were carried out using bomb calorimetry, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) analysis and thermal gravimetric analysis (TGA) to examine the efficacy of pretreatment. Evidences of an apparent delignification was substantiated by the increase in surface area from 7.719 to 44.188 m2 g−1and pore volume from 0.039 to 0.071 mlg−1 which was consistent with the decrease in energy density and distorted surface morphology of the pretreated biomass. Further, the FTIR revealed a reduced peak in the absorption spectral bands at 1636 cm−1 which confirmed the pretreatment mediated degradation of lignin and hemicellulose. This finding provides evidence on the prospects of utilizing abundantly available seawater resource as a reaction medium for sustainable biofuel production.

Non-potable water reuse: legal aspects, urban and agricultural use, and emerging technologies for the production of water for reuse Technical Note 1 – Interest topics

Sewage treatment plants (STPs) can be considered as factories for the production of water, nutrients, energy, among other resources, and the final effluent quality is determined by the technological route adopted and the operating practices. It is in these units that the standards for discharge of treated sewage into water bodies or reuse (urban, agricultural, industrial, among others) are achieved. Despite the enormous potential, there are few full-scale experiences. The absence of a more comprehensive and specific national legislation for reuse is one of the biggest obstacles to its dissemination. This technical note (TN), the first of the collection “Non-potable water reuse: legal aspects, urban and agricultural use, and emerging technologies for the production of water for reuse”, presents the topics of interest related to legal aspects, agricultural use, gray water treated in constructed wetlands, high rate algal ponds, aerobic granular sludge, dynamic membranes post UASB reactor and systems with support medium based on polyurethane foam post UASB reactor. With the information contained in this collection of TNs, it is expected to contribute to the dissemination of consolidated knowledge by experts and sanitation service providers, and technical-scientific production applied to the subject of sewage treatment and water reuse.

Dimensionless parameter method for evaluating decentralized water reuse systems in buildings

• Propose a regionalization method to design RWHs, GWRs, and HRGs. • Obtain the design curves under the stable and seasonal water demand scenarios. • The best scenarios and configurations of RWHs, GWRs, and HRGs are discussed. • GWRs are not recommended to implement in the seasonal water demand buildings. The performance of the decentralized water reuse systems that are widely implemented for the conservation of building water is affected by various characteristics, such as the location and type of building. Generalized methods to evaluate and compare different system configurations under various scenarios are currently lacking. Previously devised methods have focused on specific parameters describing buildings and are therefore not suitable for regionalized application. This study proposes a dimensionless parameter method for the evaluation of three decentralized systems in buildings with stable and seasonal daily non-potable water demands: rainwater harvesting systems (RWHs), graywater recycling systems (GWRs), and hybrid rainwater-graywater systems (HRGs). Japan was selected as a case study to illustrate the feasibility of this method. The results indicate that the favorable precipitation patterns in Japan support the use of RWHs rather than GWRs for conserving water, especially in buildings with seasonal daily non-potable water demands. Upgrading the existing systems to HRGs when RWHs and GWRs cannot meet the demand can increase the maximum water-saving efficiency by 40%. Thus, the method can effectively determine the optimum scenarios and configurations of RWHs, GWRs, and HRGs and provide policy guidance for the regional implementation of decentralized water reuse systems.

Common Effluent Treatment Plants Monitoring and Process Augmentation Options to Conform Non-potable Reuse

The stringency in effluent discharge and reuse standards has made it extremely expensive to discharge the effluents safely or reuse them. Therefore, existing wastewater treatment plants should be evaluated and improved or augmented. With this aim, five existing common effluent treatment plants (CETPs) in North India were evaluated, including: the State infrastructure Development Corporation Uttrakhand Limited (SIDCUL) Haridwar, which processes 4.5 Million Liters per day (MLD); the Industrial Model Township (IMT) Manesar Gurgaon, 55 MLD (comprising two streams of 25 and 30 MLD each); the Lawrence Road Industrial Area (LRIA), Delhi, 12MLD (12MLD LRIA); Mayapuri Industrial Area (MIA), Delhi, 12MLD; and the Integrated Industrial Estate (IIE) SIDCUL Pantnagar, 4.0 MLD. These plants were designed to produce treated effluent for non-potable reuse. Results showed that the integrated efficiency (IEa) of all CETPs was 10–20% larger than standard integrated efficiency (IEs), indicating the suitability of the technology, except for 12MLD at MIA CETP where the IEa was 20% lower than IEs, due to the absence of any biological unit in the process. Combined post-treatment of secondary effluent by coagulation, Ultrafiltration (UF), followed by ozonation for CETP SIDCUL Haridwar, was also conducted for its non-potable water reuse. This process was able to reduce Biochemical Oxygen Demand (BOD) by 77%, Chemical Oxygen Demand (COD) by 76%, turbidity by 96%, and Total Suspended Solids (TSS) by 100%. All these parameters confirmed the effluent standards for non-potable reuse. The color was reduced to 4.0 from 42.0 Pt-Co units by the exposure ozone concentration of 8.3 mg/L for up to 4.0 min on the treated water from SIDCUL CETP, which reduced the color by 90% and complied with reuse standards. Hence Combined post treatment by coagulation, UF followed Ozonation of secondary treated effluent could be a better option for the potable reuse of treated water in various domestic and industrial applications.

Small Systems: Put Your Wastewater and Stormwater to Use!

Small systems can realize many benefits by harvesting and applying traditionally nonpotable water sources to serve community, industrial, environmental, and other uses, including potable reuse.

National water footprints and embodied environmental consequences of major economic sectors-a case study of Japan

Due to the challenges of an increasing planetary temperature and limited natural resources, quantifying anthropogenic pressure on the natural environment is of increasingly great importance. Although “footprint” has been widely discussed for describing certain anthropogenic impacts on the environment, comprehensive analyses of multiple environmental footprints are seldom conducted. Hence, this study tries to evaluate consumption-based footprints covering water, greenhouse gasses, and pollutants by using the environmentally extended input-output table. Taking Japan as an example, six water sources, including potable water, non-potable water, underground water, green water, reclaimed water, and seawater, are thoroughly analyzed to determine the water footprint from production to consumption. In addition, the greenhouse gas footprint and pollutant footprint are also analyzed separately. The comprehensive insights from consumption-based accounting provide another picture of environmental burdens, which will benefit future consumption-based measurements.

High-performance solar-driven interfacial evaporation through molecular design of antibacterial, biomass-derived hydrogels

Hydrogel has been regarded as one of the most promising candidates for next-generation solar evaporation technology to produce freshwater from non-potable water. However, synthesizing hydrogel absorbers that can precisely regulate water state and significantly reduce the water vaporization enthalpy remains a grand challenge. Herein, we report the rational design of a novel hydrogel hybrid solar evaporator constructed by poly(vinyl alcohol) and sodium lignosulfonate (SLS), with addition of carbon nanotube as a light absorption material. The abundant sulfonate and hydroxyl groups of SLS enhance the interplay between hydrogel and water molecule through electrostatic interaction and hydrogen bond. As such, the presence of SLS not only remarkably promotes the hydrophilicity and water transport of hydrogel, but also precisely tunes the state of water molecule and the content of intermediate water for reducing the water vaporization enthalpy. The combined advantageous features endow the as-prepared hydrogel with an evaporation rate up to 2.09 kg m−2 h−1 under 1 Sun illumination, along with good anti-acid/basic abilities, antibacterial property, high salt-tolerance, and self-cleaning capability in purifying different types of wastewater. Finally, an outdoor solar seawater desalination device is designed to generate drinking water from seawater. The daily drinking water production amount per square meter is ca. 13 kg, which satifies the five adults' daily water consumption (12.5 kg). The present study highlights that rationally constructing the molecular architecture of hydrogel and tuning the interplay between water and hydrogel are effective strategies to fabricate advanced hydrogel solar evaporators for addressing the global freshwater shortage.

Nanoarchitectonics of Metal-Organic Frameworks for Capacitive Deionization via Controlled Pyrolyzed Approaches.

Next-generation desalination technologies are needed to meet the increasing demand for clean water. Capacitive deionization (CDI) is a thermodynamically efficient technique to treat non-potable water with relatively low salinity. The salt removal capacity and rate of CDI are highly dependent on the electrode materials, which are preferentially porous to store ions through electrosorption and/or redox reactions. Metal-organic frameworks (MOFs) with "infinite" combinations of transition metals and organic linkers simplify the production of carbonaceous materials often with redox-active components after pyrolysis. MOFs-derived materials show great tunability in both compositions and structures but require further refinement to improve CDI performance. This review article summarizes recent progress in derivatives of MOFs and MOF-like materials used as CDI electrodes, focusing on the structural and compositional material considerations as well as the processing parameters and electrode architectures of the device. Furthermore, the challenges and opportunities associated with this research area are also discussed.

Reliability Analysis of Rainwater Harvesting Tanks for Irrigation Use in Greenhouse Agriculture

Rainwater harvesting is an ancient water management practice that has been used to cover potable and non-potable water needs. In recent years, this practice is adopted as a promising alternative and sustainable source of water to meet irrigation needs in agriculture in arid and semi-arid regions. In the present study, a daily water balance model was applied to investigate the size of rainwater tanks for irrigation use in greenhouse begonia and tomato cultivation in two regions of Greece with significant greenhouse areas. For the application of the water balance model, daily rainfall depth values of a 12-year time series (2008–2020) from representative rainfall stations of the study areas were used, as well as the daily water needs of the crops. The greenhouse roof was assumed to be the water collection area of the rainwater harvesting system with values ranging from 1000 to 10,000 m2. The analysis of the results showed that in the case of the begonia crop, the covered tanks ranged from 100 to 200 m3 per 1000 m2 greenhouse area with a reliability coefficient that ranged from 65 to 72%, respectively, to meet the water needs of plants. Further increase of the reliability coefficient was carried out with disproportionately large volumes of tanks. In the case of the tomato crop, covered tank volumes ranged from 100 to 290 m3 per 1000 m2 of greenhouse area, and had a reliability coefficient of 90% to 100%, respectively, while uncovered tanks had a maximum reliability coefficient of 91% for a critical tank volume of 177 m3 per 1000 m2 of greenhouse area and decreased for any further increase of tank volume.

The use of passive baffles to increase the yield of a single slope solar still

Despite their relative simplicity, single slope solar stills remain one of the most viable solutions to the production of freshwater from saline and non-potable water sources. Over the years, numerous researchers have attempted to improve the yield of single slope solar stills through changes to their geometry and the use of various design modifications. Despite this long history of research, one modification that has not been fully explored is the use of passive baffles to alter the natural convection inside them.Though baffles have frequently been used to suppress natural convection in enclosures, there may also be the opportunity to use them to enhance natural convection. This judicious placement of baffles to enhance the natural convection could potentially improve the yield from single slope solar stills, however it has not been well explored in the literature.To address this issue, this work examined the effect of vertically mounted passive baffles on the natural convection inside a single slope solar still geometry. In this vein, a computational fluid dynamics simulation was conducted for a still containing a baffle, with the results validated experimentally using particle image velocimetry. On this basis, subsequent simulations explored the effect of baffle length and position on stills with cover angles from 10–60°. The results showed that baffles did have a marked influence on the natural convection flow field and could increase the natural convection heat transfer coefficient, which is directly proportional to a solar still’s yield, by up to 20%.It was also found that short baffles enhanced natural convection at low cover angles, while baffles mounted close to the front of a still provided an improvement to the transfer processes over the widest range of conditions. Finally, the work led to the development of a relationship to describe the effect of baffles on natural convection, as shown in Equation (1), that it is hoped will aid designers of single slope solar stills in the future.(1)Nu'=Ra'0.188∗AR-0.29∗cosθ-0.5∗bB0.08∗dD0.09

Validation of the MYChrOme™ Culture Plate for Detection and Differentiation of Rapid-Growing Nontuberculous Mycobacteria in Potable and Non-Potable Water: AOAC Performance Tested MethodSM 062101.

BackgroundThe MYChrOme™ Culture Plate is a chromogenic media for the detection and differentiation of rapid-growing nontuberculous mycobacteria (NTM) in water, aided by MYCOn™ decontamination to reduce background microbiota.ObjectiveEvaluate the MYChrOme Culture Plates for the detection of rapid-growing NTM in potable and non-potable water as part of the AOAC Performance Tested Method(s)SM program.MethodsInclusivity and exclusivity of MYChrOme were evaluated with 50 target and 30 non-target organisms. Method robustness and lot stability of MYChrOme were analyzed. The candidate method was compared to a modified US Food and Drug Administration (FDA) Method: U.S. FDA—Isolation and Identification of Nontuberculous Mycobacteria in Tattoo Inks using an equivalency test. The matrix study consisted of artificially contaminated potable water and naturally contaminated non-potable water. Independent laboratory testing was conducted to verify method performance in non-potable water.ResultsThe inclusivity of MYChrOme was 94% within one week, and 98% within two weeks. The exclusivity was 96% for untreated samples and 100% for treated samples. The candidate method remained statistically equivalent for robustness and a three-month shelf-life was confirmed. For both matrixes, the candidate and reference methods were not equivalent, with more colonies enumerated on the candidate method except for one contamination level of the potable matrix.ConclusionThe MYChrOme culture method can successfully detect and differentiate rapid-growing NTM in the matrixes tested, with sensitivity equivalent or higher than the reference method.HighlightsThe MYChrOme culture plate offers differentiation of rapid-growing NTM colonies, improved detection in non-potable samples with MYCOn decontamination, and results within 7 days.

Evaluating low impact development practices potentials for increasing flood resilience and stormwater reuse through lab-controlled bioretention systems.

Low impact development practices (LID) as alternative measures of urban drainage can be used within the approach of resources recycling and co-management. This study evaluates the potential contribution of a bioretention system to flood control, non-potable water demands (NPD) and resources co-management. Bioretention setups were tested experimentally under variable conditions to identify operational key-factors to multiple purposes. Additionally, the efficiencies obtained for laboratory scale were extrapolated for household and watershed scale, quantifying the indicators of water demand reduction (WDR), energy demand reduction (EDR) and carbon emission reduction (CER) for hybrid systems with LID. The laboratory results indicated that the use of a bioretention with a submerged zone can improve the quality of the water recovered for reuse, while maintaining the efficiency of runoff retention and peak flow attenuation. Comparing the bioretention effluent quality with the Brazilian standards for stormwater reuse, the parameters color, turbidity, E. coli and metals were above the limits, indicating the necessity of a better treatment for solids particles and disinfection. Expanding the analysis to watershed scale, the bioretention helped to reduce NPD demands up to 45%, leading to a reduction in energy demand and carbon emission from the centralized water supply system.

A Review on the Performance of Concrete Containing Non-Potable Water

Construction industries consume huge amounts of potable water during activities such as washing of aggregates, stone crushing, manufacturing, and curing of concrete, mortars, grouts, and wetting of masonry bricks. It is also responsible for wastewater generated during the finishing and cleaning of buildings and construction equipment. Therefore, the water-footprint of construction industry cannot be ignored to reach the state-of-the art sustainability. This study reviewed the technical properties of construction materials made with non-potable water (NPW), i.e., domestic and industrial sewage. The study identified the positive and negative effects of non-potable water on the fresh- and hardened-state properties of concrete. This study also identified the gaps in the literature that can be analysed in order to produce reliable information related to the use of different types of NPW on the properties of concrete.

A Tale of Two Communities: Adopting and Paying for an In-Home Non-Potable Water Reuse System in Rural Alaska

A Tale of Two Communities: Adopting and Paying for an In-Home Non-Potable Water Reuse System in Rural Alaska

Stormwater Harvested from Permeable Pavements as a Means to Save Potable Water in Buildings

The main objective of this work is to analyse the potential for potable water savings in university buildings by using stormwater collected from permeable pavements. Six buildings located on the campus of the Federal University of Santa Catarina (UFSC) were selected to obtain monthly water consumption patterns and parking lot areas. The same six buildings were then evaluated considering their location in eight different cities in Brazil, with different rainfall patterns. Simulations using the computer programme Netuno were run to obtain the potential for potable water savings in each building and city combined. The structural design of permeable pavements was also assessed using two methods available in the literature, that is, the American Association of State Highway and Transportation Officials (AASHTO) and Brazilian Portland Cement Association (ABCP). The hydrological-hydraulic design of the permeable pavement was also carried out. The designed thicknesses were compared with the thicknesses obtained using the computer programme Permeable Design Pro. The potential for potable water savings between 18.4% and 84.8% was obtained, depending on the city, building and non-potable water demand considered. For the structural design, the thicknesses obtained by using both methods were similar; however, it was observed that the AASHTO method better represents the pavement model. Regarding the hydrological-hydraulic design, the differences obtained show that the simplification performed for the pavement drainage was in favour of safety. In conclusion, the use of permeable pavements in stormwater harvesting systems is promising, aligning the drainage aid, structural capacity and potential for saving potable water.

An interlaboratory study on EPA methods 537.1 and 533 for per‐ and polyfluoroalkyl substance analyses

AbstractThe US Environmental Protection Agency (EPA) Methods 537.1 and 533 were developed for analysis of per‐ and polyfluoroalkyl substances (PFAS) in drinking water. They have been also widely used for source water assessments. However, there are few studies reportedly supporting such applications. The main purpose of this interlaboratory study was to evaluate the performance of these two methods for use with both potable and nonpotable waters. The obtained matrix spike recoveries indicate that both methods are generally applicable for analysis of PFAS in pristine nonpotable water matrices, however, with a notable challenge for effectively extracting long‐chain PFAS from some nonpotable water matrices. Another challenge associated with EPA Method 533 is the impacts likely caused by co‐extracted common inorganic anions on those PFAS that do not have their own isotopically labeled analogues available. The experimental results indicate that these challenges can be successfully resolved or reduced by enhancing postextraction bottle rinsing and elution procedures.Article Impact StatementThis study indicates that Environmental Protection Agency Methods 537.1 and 533 are applicable for pristine nonpotable water per‐ and polyfluoroalkyl substance analysis or source water assessment.