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The toxicity and persistence of heavy metals has become a serious problem for humans. These heavy metals accumulate mainly in wastewater from various industries' discharged effluents. The recent trends in research are now focused not only on the removal efficiency of toxic metal particles, but also on their effective reuse as catalysts. This review discusses the types of heavy metals obtained from wastewater and their recovery through commonly practiced physico-chemical pathways. In addition, it covers the advantages of the new system for capturing heavy metals from wastewater, as compared to older conventional technologies. The discussion also includes the various structural aspects of trapping systems and their hypothesized mechanistic approaches to immobilization and further rejuvenation of catalysts. Finally, it concludes with the challenges and future prospects of this research to help protect the ecosystem.

In this report, we provided an overview of the prevalence, control, and prevention of water-borne arsenicosis in China during 2001-2016. Random sampling was continuously performed during 2001-2010 to find villages having high levels of arsenic (>50 µg/L) in drinking water. The high-arsenic-exposure villages with more geographically dispersed water supplies were subsequently analyzed for characteristics of arsenic distribution, and villages with relatively large populations were investigated for arsenicosis. The results showed that among 32,673,677 inhabitants in 36,820 villages, 1,894,587 inhabitants in 2,476 villages were at risk of high arsenic exposure. Among the 33,318 drinking water sources surveyed in 625 high-arsenic-exposure villages, 9,807 drinking water sources that contained high levels of arsenic (>50 µg/L) were identified. The overall prevalence rate of arsenicosis was 1.93%. Further, some representative villages were chosen to monitor arsenicosis annually, showing that the prevalence rate of arsenicosis was lower in villages with arsenic-safe water supplies than in villages without arsenic-safe water supplies. To the best of our knowledge, this report provides the most comprehensive assessment of the distribution of high arsenic exposure and arsenicosis in China until now.

Wastewater irrigation is a common practice in developing countries due to water scarcity and increasing demand for food production. However, there are health risks and ecological risks associated with this practice. Small-scale wastewater treatment plants (WWTPs) intend to decrease these risks but still face management challenges. This study assessed how the management status of five small-scale WWTPs in Cochabamba, Bolivia affects health risks associated with consumption of lettuce and ecological risks due to the accumulation of nutrients in the soil for lettuce and maize crops. Risk simulations for three wastewater irrigation scenarios were: raw wastewater, actual effluent and expected effluent. Results showed that weak O&M practices can increase risk outcomes to higher levels than irrigating with raw wastewater. Improving O&M to achieve optimal functioning of small-scale WWTPs can reduce human health risks and ecological risks up to 2 log 10 DALY person -1 year -1 and to 2 log 10 kg nitrogen ha -1 accumulated in soil, respectively.

Outbreaks associated with treated recreational water can be caused by pathogens or chemicals in aquatic venues such as pools, hot tubs, water playgrounds, or other artificially constructed structures that are intended for recreational or therapeutic purposes. For the pseriod 2015-2019, public health officials from 36 states and the District of Columbia (DC) voluntarily reported 208 outbreaks associated with treated recreational water. Almost all (199; 96%) of the outbreaks were associated with public (nonbackyard) pools, hot tubs, or water playgrounds. These outbreaks resulted in at least 3,646 cases of illness, 286 hospitalizations, and 13 deaths. Among the 155 (75%) outbreaks with a confirmed infectious etiology, 76 (49%) were caused by Cryptosporidium (which causes cryptosporidiosis, a gastrointestinal illness) and 65 (42%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms). Cryptosporidium accounted for 2,492 (84%) of 2,953 cases resulting from the 155 outbreaks with a confirmed etiology. All 13 deaths occurred in persons affected by a Legionnaires' disease outbreak. Among the 208 outbreaks, 71 (34%) were associated with a hotel (i.e., hotel, motel, lodge, or inn) or a resort, and 107 (51%) started during June-August. Implementing recommendations in CDC's Model Aquatic Health Code (MAHC) (1) can help prevent outbreaks associated with treated recreational water in public aquatic venues., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

The paper assessed access to WASH service in the Jariban district of Somalia. One hundred and sixty-seven households were sampled to administer a questionnaire. Central tendency and logistical regression were used to analyse the data in SPSS 26. The findings show that access to safe drinking water sources is 57.5%. Of the 42.5% of respondents who did not access safe drinking water source, only 10.8% confirmed that they treat drinking water at the point of use. The main reason for household water treatment was the positive mindset (.272) of the household head towards water treatment. The majority (80.2%) of the respondents access approximately 13 litres per person per day. Woman-headed households were more likely to treat water before drinking than male-headed households. Only 26.9% of the respondents accessed basic sanitation. Of the respondents, 55.7% did not share latrines, while 44.3% share resulting in open defecation. WASH access in the study area remains low, resulting in health-related risks, including diarrhoeal disease. The limitation is that the paper only focused on access to WASH facilities in fragile contexts. A cross-sectional analysis of biological, physical and chemical properties of water at the source and point of use is recommended for further research., Competing Interests: We have no conflicts of interest to disclose.

In present study, dyeing wastewater samples were collected from three typical dyeing wastewater treatment plants in Wujiang, Shengze and Shanghai, China. Physicochemical properties and biotoxicity indicators (luminescent bacteria acute toxicity and umu genotoxicity) were tested and the relationships among them were analyzed. The results revealed that two biotoxicity indicators varied significantly among different treatment units of three plants. After treatment by plant A, luminescent bacteria acute toxicity of dyeing wastewater reduced effectively, while umu genotoxicity increased significantly. Two biotoxicity indicators exhibited decrease and increase trends during the treatment processes of plant B and plant C, respectively. Correlation analysis indicated that there was little correlation among biotoxicity indicators and physicochemical properties, meanwhile two kinds of biotoxicity indicators were relatively independent. Therefore, it was recommended that comprehensive evaluation of dyeing wastewater toxicity needs the combination of various biotoxicity indicators, and the relationship among biotoxicity indicators and physicochemical properties of dyeing wastewater should be established individually. The results of this study would offer a general understanding and evaluation of biotoxicity during actual dyeing wastewater treatment processes and provide database for toxicity reduction and management of dyeing wastewater.

Waterborne diseases are present major health problems to humanity especially in rural communities where many individuals belong to the lower socioeconomic classes (SECs). The impacts of introducing waterborne disease control measures for such communities are investigated by considering a waterborne disease model. The model is extended by introducing treatment of infected individuals and water purification as control measures. The possible benefits of considering these control measures for the various SECs are investigated. Further analyses show how different degrees of control impact the rate at which waterborne diseases are spread across SECs. The disease control model is validated by using it to study the cholera outbreak in Haiti.

Antibiotics, antimicrobial resistance determinants and human pathogens are new types of environmental pollutants that pose a great threat to human health. Wastewater treatment plants (WWTPs) are important sources of novel pollutants; however, few studies have investigated their impact on surrounding natural water. Therefore, this study used a WWTP as the entry point to explore WWTP removal efficiency of antibiotics, antimicrobial resistance determinants and human pathogens and further analyze the impact of WWTP effluent on receiving waters. The investigated WWTP had a good removal effect on fluoroquinolones, macrolides, lincomycin, sulfanilamide, tetracycline and chloramphenicol antibiotics in wastewater, and the concentration of antibiotics in the WWTP's effluent was reduced by >80% relative to the influent. In addition to cmlA, the effect of the WWTP on antimicrobial resistance determinants removal was poor, although the effluent from the WWTP had no effect on the abundance of antimicrobial resistance determinants in the receiving water. However, with the dilution of receiving water, the abundance of antimicrobial resistance determinants gradually decreased. The WWTP could reduce the abundance of bacteria by 1000 times from influent water to effluent water. The major bacteria in the influent and effluent were Bacteroidetes and Proteobacteria. After effluent is discharged into receiving water, Cyanobacteria proliferate in large quantities, which can affect the microbial structure in the environment.The abundance of Acinetobacter, which was the predominant potential human pathogen in local wastewater, decreased dramatically after wastewater treatment. We also conducted an ecological risk assessment of the antibiotics identified and found that the ecological risk AZM and CLR posed to aquatic organisms was high. Overall, we identified the efficiency of WWTP control of antibiotics, antimicrobial resistance determinants and potential human pathogens and the impact of WWTP effluent on receiving water and provided data to support the control of the investigated pollutants., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Access to safe water for drinking and domestic activities remains a challenge in emerging economies like South Africa, forcing resource-limited communities to use microbiologically polluted river water for personal and household purposes, posing a public health risk. This study quantified bacterial contamination and the potential health hazards that wastewater treatment plant (WWTP) workers and communities may face after exposure to waterborne pathogenic bacteria in a WWTP and its associated surface water, respectively., Results: Escherichia coli (Colilert®-18/ Quanti-Tray® 2000) and enterococci (Enterolert®/ Quanti-Tray® 2000) were quantified and definitively identified by real-time polymerase chain reaction targeting the uidA and tuf genes, respectively. An approximate beta-Poisson dose-response model was used to estimate the probability of infection (Pi) with pathogenic E. coli. Mean E. coli concentration ranged from 2.60E+ 02/100 mL to 4.84E+ 06/100 mL; enterococci ranged from 2.60E+ 02/100 mL to 3.19E+ 06/100 mL across all sampled sites. Of the 580 E. coli isolates obtained from this study, 89.1% were intestinal, and 7.6% were extraintestinal pathogenic E. coli. The 579 enterococci obtained were 50.4% E. faecalis (50.4%), 31.4% E. faecium, 3.5%, E. casseliflavus and 0.7% E. gallinarum. The community health risk stemming from the use of the water for recreational and domestic purposes revealed a greater health risk (Pi) from the ingestion of 1 mL of river water from upstream (range, 55.1-92.9%) than downstream (range, 26.8-65.3%) sites. The occupational risk of infection with pathogenic E. coli for workers resulting from a once-off unintentional consumption of 1 mL of water was 0% (effluent) and 23.8% (raw influent). Multiple weekly exposures of 1 mL over a year could result in a Pi of 1.2 and 100% for the effluent and influent, respectively., Conclusion: Our findings reveal that there is a potentially high risk of infection for WWTP workers and communities that use river water upstream and downstream of the investigated WWTP.

On October 6, 2017, the Zambia Ministry of Health declared a cholera outbreak in Lusaka. By December, 1,462 cases and 38 deaths had occurred (case fatality rate, 2.6%). We conducted a case-control study to identify risk factors and inform interventions. A case was any person with acute watery diarrhea (≥ 3 loose stools in 24 hours) admitted to a cholera treatment center in Lusaka from December 16 to 21, 2017. Controls were neighbors without diarrhea during the same time period. Up to two controls were matched to each case by age-group (1-4, 5-17, and ≥ 18 years) and neighborhood. Surveyors interviewed cases and controls, tested free chlorine residual (FCR) in stored water, and observed the presence of soap in the home. Conditional logistic regression was used to generate matched odds ratios (mORs) based on subdistricts and age-groups with 95% CIs. We enrolled 82 cases and 132 controls. Stored water in 71% of case homes had an FCR > 0.2 mg/L. In multivariable analyses, those who drank borehole water (mOR = 2.4, CI: 1.1-5.6), had close contact with a cholera case (mOR = 6.2, CI: 2.5-15), and were male (mOR = 2.5, CI: 1.4-5.0) had higher odds of being a cholera case than their matched controls. Based on these findings, we recommended health education about household water chlorination and hygiene in the home. Emergency responses included providing chlorinated water through emergency tanks and maintaining adequate FCR levels through close monitoring of water sources.

Although the Flint, Michigan, water crisis renewed concerns about lead (Pb) in city drinking water, little attention has been paid to Pb in private wells, which provide drinking water for 13% of the US population. This study evaluates the risk of Pb exposure in children in households relying on private wells. It is based on a curated dataset of blood Pb records from 59,483 North Carolina children matched with household water source information. We analyze the dataset for statistical associations between children's blood Pb and household drinking water source. The analysis shows that children in homes relying on private wells have 25% increased odds (95% CI 6.2 to 48%, P < 0.01) of elevated blood Pb, compared with children in houses served by a community water system that is regulated under the Safe Drinking Water Act. This increased Pb exposure is likely a result of corrosion of household plumbing and well components, because homes relying on private wells rarely treat their water to prevent corrosion. In contrast, corrosion control is required in regulated community water systems. These findings highlight the need for targeted outreach to prevent Pb exposure for the 42.5 million Americans depending on private wells for their drinking water., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

The biological treatment of landfill leachate due to high concentration of Chemical Oxygen Demand (COD), ammonia, and other toxic compounds is so difficult. One of the leachate treatment technology is the sludge biogranulation, that containing the two aerobic and anaerobic process. The aim of this study was conducted for determining the main factors affecting aerobic granule sludge formation in leachate treatment. In this study, all related papers in international databases were evaluated including Google Scholar, Science Direct, and PubMed, Also Open Access Journal Directory from 1990 until 2020 were investigated. The keywords used included Aerobic Granule Sludge (AGS), leachate treatment, Wastewater treatment, Granular Sequential Batch Reactors (GSBR), Formation Extracellular polymeric substance (EPS). Overall, 2,658 articles were retrieved of which 71 were selected after revising the titles and abstracts. Aerobic granulation has been only lately studied and a limited number of studies have been devoted to identification aspects of the process such as the organic source, and other factor affecting on formation granules. Some factors as shear stress, settling time, and the effluent discharge site have direct effect on the efficiency of aerobic granules reactor and other factors such as divalent metal ions, dissolved oxygen concentration, the ratio of height to diameter of the reactor, temperature affecting on the granulation process. If suitable conditions provide, the aerobic granule sludge process can be useful for leachate treatment., (© 2020 Walter de Gruyter GmbH, Berlin/Boston.)

Behavioural change communication interventions have been shown to be effective at improving infant and young child nutrition knowledge and practices. However, evidence in humanitarian response contexts is scarce. Using data on secondary outcomes of breastfeeding, water treatment, and knowledge from a cluster randomized control trial of the Yemen Cash for Nutrition programme's impact on child nutritional status, this paper shows that the programme significantly improved knowledge and practices for poor women with young children in the pilot districts. The intervention consisted of cash transfers and monthly group nutrition education sessions led by locally recruited community health volunteers. Data are based on self-reports by participants. Estimating impacts among all 1,945 women in 190 clusters randomly assigned to treatment versus control and controlling for baseline levels and community characteristic and adjusting for noncompliance with randomization, the programme increased the probability of breastfeeding initiation within the first hour after delivery by 15.6% points (p < .05; control = 74.4% and treatment = 83.6%), the probability of exclusive breastfeeding during the first 6 months by 14.4% points (control = 13.5% and treatment = 25.3%), the probability of households treating water consumed by adults by 16.7% points (p < .01; control = 13.9% and treatment = 23.4%), and treating water consumed by children under two by 10.3% points (p < .10; control = 31.2% and treatment = 37.9%). Impacts on knowledge and breastfeeding are similar for both literate and illiterate women, and water treatment impacts are significantly larger for literate women. This study was registered at 3ie (RIDIE-STUDY-ID-5b4eff881b29a) and funded by the Nordic Trust Fund and Consultative Group on International Agricultural Research programme on Policies, Institutions, and Markets., (© 2020 The Authors. Maternal & Child Nutrition published by John Wiley & Sons, Ltd.)

Background: The aim of the study was to assess the occupational exposure to Staphylococcus aureus bacteria, including methicillin- resistant S. aureus (MRSA) and other antibiotic-resistant strains in the municipal wastewater treatment plants (WWTPs) environment., Material and Methods: In 16 WWTPs in Poland, 33 wastewater and 253 air samples were collected in the spring-summer season. The microbiological analysis was carried out using a chromogenic medium. Species identification was carried out using the matrix assisted laser desorption ionization time-of-flight method, while the antibiotic-resistance analysis was performed with an automatic method., Results: Among 2805 bacterial isolates from the air and wastewater, 574 were identified as S. aureus species (20.5%). The presence of S. aureus species was found in 11 WWTPs (69%), among them in 11 WWTPs in raw wastewater and in 1 WWTP additionally in treated wastewater. The concentrations of S. aureus in wastewater ranged 2-1215 colony-forming units per milliliter (CFU/ml). In the air, 2 S. aureus isolates were identified in concentrations of 5 and 10 CFU/m 3 ; both samples were collected at the stage of mechanical wastewater treatment. The results revealed the following trend: the higher the outdoor temperature, the bigger the number of WWTPs with confirmed S. aureus presence. Among 149 S. aureus isolates (2 from the air and 147 from wastewater, including 2 MRSA), 100 isolates were resistant only to penicillin, while 34 isolates showed multi-antibiotic resistance (to penicillin and other drugs). It was found that isolated bacteria were resistant almost strictly to critical and highly important antibiotics in veterinary medicine., Conclusions: In general, WWTPs workers are occupationally exposed to S. aureus , including MRSA, and other antibiotic- and multi-antibiotic-resistant strains. The highest risk of infection concerns the activities carried out in direct contact with wastewater or devices through which wastewater flows, particularly at the stage of mechanical treatment. A significant source of S. aureus seems to be intensive livestock farming located in the area of the WWTPs under analysis. The study confirms the necessity to disinfect the wastewater discharging into WWTPs. Med Pr. 2020;71(3):265-78., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

The objective of this study is to provide a view of the geographic distribution of basic sanitation services offered in Parana, Brazil. Temporal distributions, spatial patterns, and clusters were determined using 2000, 2010, and 2016 data. Tabular data of the percentages of households receiving water supply, waste collection, and sanitary sewage treatments were used as the basic inputs of the study. Time series maps were created using geographic information systems (GIS) for the visualization of the temporal changes in basic sanitation rates. The spatial variation in sanitation services was measured using Moran's Global Index (Moran's I), while the Local Indicators of Spatial Association (LISA) and Getis-Ord Gi*(d) were used to identify the presence of possible clusters and hot spots in the percentage of households with sanitation services. The study showed strong evidence that the service rates for sanitary sewage were significantly lower than those for water supply and waste collection. Waste collection proved to have the highest service rate in the study area. Waste collection was also the service that increased the most in the study period, followed by the water supply service. Identification of the most vulnerable municipalities was performed using LISA and the local Getis-Ord Gi*(d) statistic. Most of the low value clusters and cold spots were detected in the southern and west-central regions, while the high value hot spots and clusters were detected in the northern and northeastern regions of the state of Parana.

Objectives: Throughout human evolutionary history, parasites and pathogens were a major cause of mortality-modern urban life with public health infrastructure has changed disease exposure. We examine associations between boiling water, using latrines, mosquito net usage, and biomarkers among the Tsimane, a nonindustrial subsistence population with little public health infrastructure., Methods: We conducted cross sectional surveys on water, latrines, and bed nets among 507 heads of households (aged 18-92 years, median age 41 years). Regression models estimated associations between behaviors and health biomarkers (ie, white blood cell count [WBC], hemoglobin, eosinophil count, and erythrocyte sedimentation rate) adjusting for age, sex, body mass index, wealth, schooling, and distance to the nearby market town., Results: Latrine use is associated with 6.5% lower WBC count (β = -679.6, P = .031, SE = 314.1), 17.4% lower eosinophil counts (β = -244.7, P = .023, SE = 107.2), and reduced odds of eosinophilia (adjusted OR = 0.40, P < .019, 95% CI = 0.18-0.86). Boiling water and mosquito net use are not significantly associated with any biomarkers measured., Conclusions: In a subsistence population currently undergoing epidemiological transition, we find that latrine use was associated with several objective measures of health. This suggests that relatively low cost and low maintenance public health interventions may wish to focus on latrine use, as there is unmet need and potential health benefits for those who use latrines. Additionally, while the cost is higher, public health organizations aimed at improving sanitation may be able to use minimally invasive field-collected biomarkers as a diagnostic to objectively test the efficacy of interventions with greater specificity than anthropometric measurements., (© 2019 Wiley Periodicals, Inc.)

Numerous of pollutants threaten our planet, for instance plastic wastes causes a huge potential risk on the environment in addition to many of emergened pollutants as pharmaceutical residue in aquatic environments which affecting ecological balance and in-turn affecting human health. Accordingly, this research proposed an innovative facile, one-step synthesis of functionalized magnetic fullerene nanocomposite (FMFN) via catalytic thermal decomposition of sustainable poly (ethylene terephthalate) bottle wastes as feedstock and ferrocene as a catalyst and precursor of magnetite. Growth mechanism of FMFN was discussed and batch experiments were achieved to examine its adsorption efficiency in relation to Ciprofloxacin antibiotic. Different adsorption parameters including time, initial Ciprofloxacin concentration, and solution temperature were investigated and optimized using Response Surface Methodology (RSM) model. In addition, a study on the antibiotic adsorption process impact on the organisms of an ecosystem was conducted using E. coli DH5α, and results validated method's efficiency in overcoming problem of appearance of antibiotic-resistant microbes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A consistent and correct use of water treatment options is fundamental for health gain from point-of-use water chlorination. In Ethiopia, empirical evidence about the consistent use and preference for by end users is scarce. The current study is intended to explore these issues using Waterguard and Bishan Gari in Kersa Health and Demographic Surveillance Site, Eastern Ethiopia. Data were collected every 2 week for 4 months and analyzed using mixed effects logistic regression. Of 377 households, 31% consistently used Waterguard and Bishan Gari in all the study waves. Product use over time within a household varied based on the perception about the products and the type of products each household received. From the exit assessment, 56% of households stated a preference for Waterguard significantly different from 5.6% of households that stated a preference for Bishan Gari. An intervention for consistent use beyond their availability and accessibility to end users is needed.

Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.

Background: Cryptosporidium is a major threat to water supplies worldwide. Various biases and obstacles in case identification are recognized. In Israel, Cryptosporidiosis was included among notifiable diseases in 2001 in order to determine the burden of parasite-inflicted morbidity and to justify budgeting a central drinking water filtration plant., Objectives: To summarize the epidemiologic features of 14 years of Cryptosporidium surveillance and to assess the effects of advanced water purification treatment on the burden of disease., Methods: From 2001 to 2014, a passive surveillance system was used. Cases were identified based on microscopic detection in stool samples. Confirmed cases were reported electronically to the Israeli Ministry of Health. Overall rates as well as age, gender, ethnicity and specific annual incidence were calculated per 100,000 population in five age groups: 0-4, 5-14, 15-44, 45-64, > 65 years., Results: A total of 522 Cryptosporidium cases were reported in all six public health districts. More cases were detected among Jews and among males, and mainly in young children, with a seasonal peak during summer. The Haifa sub-district reported 69% of the cases. Most were linked to an outbreak from the summer of 2008, which was attributed to recreational swimming pool activity. Cases decreased after installation of a central filtration plant in 2007., Conclusions: As drinking water in Israel is treated to maximal international standards, the rationale for further inclusion of Cryptosporidium among mandatory notifiable diseases should be reconsidered. Future surveillance efforts should focus on timely detection of outbreaks using molecular high-throughput testing.

Background: Water advisories, especially those concerning boiling drinking water, are widely used to reduce risks of infection from contaminants in the water supply. Since the effectiveness of boil water advisories (BWAs) depends on public compliance, monitoring the public response to such advisories is essential for protecting human health. However, assessments of public compliance with BWAs remain sparse. Thus, this study was aimed at investigating awareness and compliance among residents who had received BWAs in Baerum municipality in Norway., Method: We conducted a cross-sectional study among 2764 residents who had received water advisories by SMS in the municipality of Baerum between January and September 2017. We analysed data from two focus group discussions and an online survey sent to all residents who had received an advisory. We conducted descriptive analyses and calculated odds ratios (OR) using logistic regression to identify associations of compliance and awareness with demographic characteristics., Results: Of the 611 respondents, 67% reported that they had received a water advisory notification. Effective compliance rate with safe drinking water practices, either by storing clean drinking water or boiling tap water, after a water outage was 72% among those who remembered receiving a notification. Compliance with safe drinking water advisories was lower among men than women (OR 0.53, 95% CI 0.29-0.96), but was independent of age, education and household type. The main reason for respondents' non-compliance with safe water practices was that they perceived the water to be safe to drink after letting it flush through the tap until it became clear., Conclusions: Awareness of advisories was suboptimal among residents who had received notifications, but compliance was high. The present study highlights the need to improve the distribution, phrasing and content of water advisory notifications to achieve greater awareness and compliance. Future studies should include hard-to-reach groups with adequate data collection approaches and examine the use of BWAs in a national context to inform future policies on BWAs.

The transformation of dissolved organic nitrogen (DON) in the drinking water treatment plants could be closely associated with nitrogenous disinfection by-product (N-DBP) formation. In this study, we have assessed the molecular transformation of DON and its impact on N-DBP formation in a full scale drinking water treatment plant. Based on the result of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis, DON compounds with low molecular weight (<1 kDa) were classified as CHON, CHON 2 and CHON 3 according to the number of nitrogen atoms. Via the analytical window of van Krevelen diagrams, we found that the molecular structural features of CHON, CHON 2 and CHON 3 were not altered before the chlorination process. In detail, the CHON 2 and CHON 3 compositions were concentrated on the regions assigned to a lignin-structure while CHON compositions were also distributed in other compounds including proteins, carbohydrates and tannin. Furthermore, CHON formation was more difficult to be removed before the V-filter process. For N-DBP, chlorine-containing DON (Cl-DON) composition was likely to be removed through flocculation and sedimentation processes, whereas N-nitrosamine compounds were removed in V-filter and biological activated carbon filter processes. The health risks of aromatic structure N-nitrosamines due to the pre-chlorination of the raw water should be further studied., (Copyright © 2019. Published by Elsevier B.V.)

Microorganisms in wastewater treatment plants (WWTPs) are essential for water purification to protect public and environmental health. However, the diversity of microorganisms and the factors that control it are poorly understood. Using a systematic global-sampling effort, we analysed the 16S ribosomal RNA gene sequences from ~1,200 activated sludge samples taken from 269 WWTPs in 23 countries on 6 continents. Our analyses revealed that the global activated sludge bacterial communities contain ~1 billion bacterial phylotypes with a Poisson lognormal diversity distribution. Despite this high diversity, activated sludge has a small, global core bacterial community (n = 28 operational taxonomic units) that is strongly linked to activated sludge performance. Meta-analyses with global datasets associate the activated sludge microbiomes most closely to freshwater populations. In contrast to macroorganism diversity, activated sludge bacterial communities show no latitudinal gradient. Furthermore, their spatial turnover is scale-dependent and appears to be largely driven by stochastic processes (dispersal and drift), although deterministic factors (temperature and organic input) are also important. Our findings enhance our mechanistic understanding of the global diversity and biogeography of activated sludge bacterial communities within a theoretical ecology framework and have important implications for microbial ecology and wastewater treatment processes.

Disinfection is an indispensable water treatment process for killing harmful pathogens and protecting human health. However, the disinfection has caused significant public concern due to the formation of toxic disinfection by-products (DBPs). Lots of studies on disinfection and DBPs have been performed in the world since 1974. Although related studies in China started in 1980s, a great progress has been achieved during the last three decades. Therefore, this review summarized the main achievements on disinfection and DPBs studies in China, which included: (1) the occurrence of DBPs in water of China, (2) the identification and detection methods of DBPs, (3) the formation mechanisms of DBPs during disinfection process, (4) the toxicological effects and epidemiological surveys of DBPs, (5) the control and management countermeasures of DBPs in water disinfection, and (6) the challenges and chances of DBPs studies in future. It is expected that this review would provide useful information and reference for optimizing disinfection process, reducing DBPs formation and protecting human health., (Copyright © 2019. Published by Elsevier B.V.)

In recent years, there has been a growing interest on the occurrence of antibiotic-resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in treated and untreated drinking water. ARB and ARGs pose a public health concern when they transfer antibiotic resistance (AR) to human pathogens. However, it is still unclear whether the presence of environmental ARB and ARGs in source water, drinking water treatment plants, and drinking water distribution systems has any significant impact on human exposure to pathogenic ARB. In this review, we critically examine the occurrence of AR in groundwater, surface water, and treated distributed water. This offered a new perspective on the human health threat posed by AR in drinking water and helped in crafting a strategy for monitoring AR effectively. Using existing data on removal of ARB and ARGs in drinking water treatment plants, presence and proliferation of AR in drinking water distribution systems, and mechanisms and pathways of AR transfer in drinking water treatment plants, we conclude that combining UV-irradiation with advanced oxidative processes (such as UV/chlorine, UV/H 2 O 2 , and H 2 O 2 /UV/TiO 2 ) may enhance the removal of ARB and ARGs, while disinfection may promote horizontal gene transfer from environmental ARB to pathogens. The potential human health risks of AR were determined by examining human exposure to antibiotic resistant human pathogens and re-evaluating waterborne disease outbreaks and their links to environmental AR. We concluded that integrating disease outbreak analysis, human exposure modelling, and clinical data could provide critical information that can be used to estimate the dose-response relationships of pathogenic ARB in drinking water, which is required for accurate risk assessments., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Antibiotic resistance is extensively detected in drinking water sources, threatening its safety and human health, which deserves further attention to the removal of antibiotic resistance genes (ARGs) in the drinking water system. In this study, the occurrence and reduction of integrase gene intI1 and forty-one ARG subtypes, which confers resistance to six antibiotic classes (β-lactam, aminoglycoside, macrolide, tetracycline, sulfonamide, and quinolone), were investigated in a drinking water treatment plant (DWTP). Seventeen ARG subtypes with absolute concentrations ranging from 1.4 × 10 0 to 7.3 × 10 5 and 3.9 × 10 4 genes/mL (intI1) were detected in the raw water; and sul1 and sul2 were the two dominant ARG subtypes. Overall, the whole DWTPs achieved 0.03-2.4 log reduction of ARGs compared with those presented in raw water. The reduction efficiencies of sul1, strA, and intI1 were the highest (1.0-2.4 log) in both conventional and advanced processes. However, the levels of sul1, sul2, and ermC still remained high (1.3 × 10 0 -1.9 × 10 4 genes/mL) in finished water. The treatment units, including pre-flocculation/sedimentation/sand filtration, and ozonation units, were beneficial for the reduction of ARGs, which was mostly ascribed to the decline in biomass and the strong oxidizing properties of ozone. However, the reduction effect was subsequently counteracted by the granular activated carbon and chlorination units. This study provides basic data for ARG pollution in the drinking water system, and suggests that ARGs persist in drinking water, even after conventional chlorination or advanced treatment processes, highlighting the need for new and efficient water purification technologies., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: In rapidly urbanizing centres in Tanzania, water supply infrastructure lags behind the speed of urbanization, affecting water availability and accessibility. We believe that inhabitants' access water using various ways which are characterizable and understanding them could inform about the risks to hygiene-related diseases. This study aimed at characterizing water-handling chains and their microbial profiles in Babati town to inform hygiene education policy and water supply planning., Methodology: A cross-sectional study design employing a proportional sampling for each of the 8 wards was conducted between November 2016 and March 2017. A total of 564 samples of water were collected using the USA EPA procedures from 37 randomly selected households. Water samples were collected from the common sources of water as well as from the downstream points to multiple storage containers. Using EPA membrane filtration techniques, two microorganisms were tested: fecal coliforms and Salmonella typhi. Results . Three water-handling chains/patterns in Babati town were determined, and they were as follows: (i) untreated-source-to-treated-reservoir-to-households ( untrS2trR2HH ) chain, (ii) untreated-source-to-untreated-reservoir-to-households ( untrS2untrR2HH ) chain; (iii) untreated-source-straight-to-households ( untrS2HH ) chain. In terms of the microbial profile, the most contaminated water-handling chain was the untreated-source-straight-to-households ( untrS2HH ). The number of users in these three chains was not statistically significantly different ( p =0.5226), meaning that all people utilized the various chains almost equally, depending on the water situation. Most households (83%) did not treat their drinking water making those using the untreated-source-to-household chain ( untrS2HH ) most vulnerable to waterborne diseases., Conclusion: Determination of water-handling chains among the household is a novel approach which allows an understanding of the points at which highest fecal loading occurs. This approach therefore may inform the development of policies in the areas of household hygiene education, drinking water treatment, and water supply planning in urbanized towns in Tanzania and other developing countries.

Preoxidation is an important unit process which can partially remove organic and microbial contaminations. Due to the high concentrations of organic matter entering the water treatment plant, originating from surface water resources, preoxidation by using chlorinated compounds may increase the possibility of trihalomethane (THM) formation. Therefore, in order to reduce the concentration of THMs, different alternatives such as injection of potassium permanganate are utilized. The present study attempts to investigate the efficiency of the microbial removal from raw water entering the water treatment plant No. 1 in Mashhad, Iran, through various doses of potassium permanganate. Then, an examination of the predictive models is done in order to indicate the residual Escherichia coli and total coliform resulted from injecting the potassium permanganate. Finally, the coefficients of the proposed models were optimized using the genetic algorithm. The results of the study show that 0.5 mg L -1 of potassium permanganate would remove 50% of total coliform as well as 80% of Escherichia coli in the studied water treatment plant. Also, assessing the performance of different models in predicting the residual microbial concentration after injection of potassium permanganate suggests the Gaussian model as the one resulting the highest conformity. Moreover, it can be concluded that employing smart models leads to an optimization of the injected potassium permanganate at the levels of 27% and 73.5%, for minimum and maximum states during different seasons of a year, respectively.

This study intends to explore fuzzy logic control on clean water turbidity process with dissolved air flotation (DAF). Three different strategies were tested to regulate clean water turbidity by manipulating the saturator vessel flow output aiming for low actuators control effort. Saturator pressure was the manipulated variable (MV) in the first control loop named SISO I. The second control loop, SISO II, used recycle stream valve opening as MV. The third control loop (MISO) was developed applying fuzzy logic instead PID control. Several performance criteria were used to analyze the process control performance such as integral absolute error (IAE), recycle stream valve and saturator vessel pressure regulating valve control efforts, ECV 01 and ECV 02 respectively. Results from SISO I and SISO II strategies showed that recycle stream is a better MV than saturator vessel pressure for clean water turbidity control in the DAF process. Only SISO II and MISO strategies proved to be capable of regulating the process variable. However, MISO control showed better performance based on IAE value against SISO II, with a reduction of 11.24% on its value, even the recycle stream valve control effort for MISO control being fairly higher than that for SISO II. Nevertheless, fuzzy logic control application gave rise to better turbidity control, and consequently prevented the excessive use of clean water in the recycling stream.

The work addresses the effect of total suspended solids (TSS) on disinfection by peracetic acid (PAA) concerning both PAA decay and bacterial inactivation kinetics. The effect of TSS on PAA decay was evaluated at five TSS concentrations (5, 40, 80, 120 and 160 mg/L), obtained from stock TSS solutions prepared from activated sludge samples. The influence of the soluble matter associated to the suspended solids on PAA decay was evaluated separately, using the same stock TSS solution after the removal of solids by filtration. The contributions of suspended and soluble fractions were found to be independent, and a predictive model formed by two additive sub-models was proposed to describe the overall PAA decay kinetics. Moreover, an uncertainty analysis was performed by a series of Monte Carlo simulations to propagate the uncertainties associated to the coefficients of the model. Then, the disinfectant dose (mg/L min) was highlighted as the main parameter determining disinfection efficiency on a pure culture of E. coli and an inactivation kinetic model was developed based on the response of E. coli to various PAA doses. Finally, the effect of TSS (40 and 160 mg/L) on the inactivation of free-swimming E. coli was investigated at two PAA doses (5 and 20 mg/L min). TSS reduced inactivation extent an average of 0.4 logs at 5 mg/L min and 1.5 logs at 20 mg/L min. It was hypothesized that this might be due to the formation of bacteria aggregates as defense mechanism against disinfection, enhanced by the presence of solids., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Diarrheal disease attributable to water and sanitation can be prevented using point-of-use water treatment. In Ethiopia, a small number of households treat water at point-of-use with appropriate methods. However, evidence on factors associated with household use of these treatment methods is scarce. Therefore, this study is intended to explore the household use of appropriate point-of-use water treatment and associated factors in Ethiopia., Methods: The data of 2005, 2011, and 2016 Ethiopian demographic and health surveys were used for analysis. Households reportedly treating water with bleach, boiling, filtration, and solar disinfection in each survey are considered as treating with appropriate treatment methods. Household water treatment with these treatment methods and factors associated was assessed using bivariate and multivariable regression. In addition, a region level difference in the treatment use was assessed by using multilevel modeling., Results: The number of households that reported treating water with appropriate water treatment methods was 3.0%, 8.2%, and 6.5% respectively in 2005, 2011, and 2016. Household heads with higher education had 5.99 (95% CI = 3.48, 10.33), 3.61 (95% CI = 2.56, 5.07), and 3.43 (95% CI = 2.19, 6.37) times higher odds of using the treatment methods respectively in 2005, 2011, and 2016 compared to household heads who had no education. There was a significantly high number of households that used appropriate water treatment methods in 2011 (AOR = 2.78, 95% CI = 2.16, 3.57) and 2016 (AOR = 2.18, 95% CI = 1.64, 3.89) compared to 2005 data. In pooled data analysis, the reported use of the treatment methods is associated with household head education, residency, drinking water sources, and owning radio and television. From a multilevel modeling, within-region variation is higher than between-region variations in the use of treatment methods in each survey., Conclusions: Below 10% of households reportedly treating water at point-of-use in each survey attributable to different factors. Designing intervention strategies for wide-scale use of treatment methods at the country level is fundamental.

Aims: In biosand filters (BSF), treatment is largely driven by the development of a biolayer (schmutzdecke) which establishes itself during the startup phase. In this study, the effect of changing influent total organic carbon (TOC) loading on the removal efficiency of Vibrio cholerae in laboratory-operated BSFs was quantified., Methods and Results: BSFs were charged with high, medium or low TOC influents and removal efficacy and schmutzdecke composition was monitored over 2 months. The highest V. cholerae removal efficiencies were observed in the BSF receiving the lowest TOC. Schmutzdecke composition was found to be influenced by influent TOC, in terms of microbial community structure and amount of extracellular polymeric substance (EPS)., Conclusions: Physical/chemical attachment was shown to be important during startup. The BSF receiving influent water with lower TOC had a higher attachment coefficient than the BSF receiving high TOC water, suggesting more physical/chemical treatment in the lower TOC BSF. The high TOC BSF had more EPS than did the biofilm from the low-TOC BSF, suggesting that schmutzdecke effects may be more significant at high TOC., Significance and Impact of the Study: Overall, this study confirms that influent water characteristics will affect BSF treatment efficacy of V. cholerae especially during the startup phase., (© 2018 The Society for Applied Microbiology.)

Algal photosynthesis plays a key role in the removal mechanisms of waste stabilization ponds (WSPs), which is indicated in the variations of three parameters, dissolved oxygen, pH, and chlorophyll a. These variations can be considerably affected by extreme climatic conditions at high altitude. To investigate these effects, three sampling campaigns were conducted in a high-altitude WSP in Cuenca (Ecuador). From the collected data, the first application of structure equation modeling (SEM) on a pond system was fitted to analyze the influence of high-altitude characteristics on pond performance, especially on the three indicators. Noticeably, air temperature appeared as the highest influencing factors as low temperature at high altitude can greatly decrease the growth rate of microorganisms. Strong wind and large diurnal variations of temperature, 7-20 °C, enhanced flow efficiency by improving mixing inside the ponds. Intense solar radiation brought both advantages and disadvantages as it boosted oxygen level during the day but promoted algal overgrowth causing oxygen depletion during the night. From these findings, the authors proposed insightful recommendations for future design, monitoring, and operation of high-altitude WSPs. Moreover, we also recommended SEM to pond engineers as an effective tool for better simulation of such complex systems like WSPs.

To enable small communities to benchmark the energy efficiency of their water resource recovery facilities (also known as wastewater treatment facilities), multiple linear regression models of electric and overall energy intensity (kWh/m3) were created using data from Nebraska and Pennsylvania. Key variables found to be significant include: facility type, supplemental energy usage for sludge treatment, average flow, percent design flow, climate controlled floor area, effluent NH3-N, and influent CBOD5. The results show that energy use models for small systems differ from those for large facilities and that regulatory changes can affect energy usage. Step changes in the data for facilities that changed operators highlight the importance of operational decisions on energy efficiency for small facilities serving fewer than 10,000 people. Differences were observed between the models of data from specific states. Although these models may not include all factors that account for variability in energy use, they can provide a reference benchmark for small WRRFs.

Presently, concentrations of fecal indicator bacteria (FIB) in raw water sources are not known before water undergoes treatment, since analysis takes approximately 24h to produce results. Using data on water quality and environmental variables, models can be used to predict real time concentrations of FIB in raw water. This study evaluates the potentials of zero-inflated regression models (ZI), Random Forest regression model (RF) and adaptive neuro-fuzzy inference system (ANFIS) to predict the concentration of FIB in the raw water source of a water treatment plant in Norway. The ZI, RF and ANFIS faecal indicator bacteria predictive models were built using physico-chemical (pH, temperature, electrical conductivity, turbidity, color, and alkalinity) and catchment precipitation data from 2009 to 2015. The study revealed that pH, temperature, turbidity, and electrical conductivity in the raw water were the most significant factors associated with the concentration of FIB in the raw water source. Compared to the other models, the ANFIS model was superior (Mean Square Error=39.49, 0.35, 0.09, 0.23CFU/100ml respectively for coliform bacteria, E. coli, Intestinal enterococci and Clostridium perfringens) in predicting the variations of FIB in the raw water during model testing. However, the model was not capable of predicting low counts of FIB during both training and testing stages of the models. The ZI and RF models were more consistent when applied to testing data, and they predicted FIB concentrations that characterized the observed FIB concentrations. While these models might need further improvement, results of this study indicate that ZI and RF regression models have high prospects as tools for the real-time prediction of FIB in raw water sources for proactive microbial risk management in water treatment plants., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Mediterranean-African countries (MACs) face a major water crisis. The annual renewable water resources are close to the 500 m 3 /capita threshold of absolute water scarcity, and water withdrawals exceed total renewable water resources by 30%. Such a low water availability curbs economic development in agriculture, which accounts for 86% of freshwater consumption. The analysis of the current situation of wastewater treatment, irrigation, and water management in MACs and of the research projects targeted to these countries indicates the need for 1) an enhanced capacity to analyze water stress, 2) the development of water management strategies capable of including wastewater reuse, and 3) development of locally adapted water treatment and irrigation technologies. This analysis shaped the MADFORWATER project (www.madforwater.eu), whose goal is to develop a set of integrated technological and management solutions to enhance wastewater treatment, wastewater reuse for irrigation, and water efficiency in agriculture in Egypt, Morocco, and Tunisia. MADFORWATER develops and adapts technologies for the production of irrigation-quality water from drainage canals and municipal, agro-industrial, and industrial wastewaters and technologies for water efficiency and reuse in agriculture, initially validated at laboratory scale, to 3 hydrological basins in the selected MACs. Selected technologies will be further adapted and validated in 4 demonstration plants of integrated wastewater treatment and reuse. Integrated strategies for wastewater treatment and reuse targeted to the selected basins are developed, and guidelines for the development of integrated water management strategies in other basins of the 3 target MACs will be produced. The social and technical suitability of the developed technologies and nontechnological tools in relation to the local context is evaluated with the participation of MAC stakeholders and partners. Guidelines on economic instruments and policies for the effective implementation of the proposed water management solutions in the target MACs will be developed. Integr Environ Assess Manag 2018;14:447-462. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)., (© 2018 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).)

Outbreaks associated with exposure to treated recreational water can be caused by pathogens or chemicals in venues such as pools, hot tubs/spas, and interactive water play venues (i.e., water playgrounds). During 2000-2014, public health officials from 46 states and Puerto Rico reported 493 outbreaks associated with treated recreational water. These outbreaks resulted in at least 27,219 cases and eight deaths. Among the 363 outbreaks with a confirmed infectious etiology, 212 (58%) were caused by Cryptosporidium (which causes predominantly gastrointestinal illness), 57 (16%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms), and 47 (13%) by Pseudomonas (which causes folliculitis ["hot tub rash"] and otitis externa ["swimmers' ear"]). Investigations of the 363 outbreaks identified 24,453 cases; 21,766 (89%) were caused by Cryptosporidium, 920 (4%) by Pseudomonas, and 624 (3%) by Legionella. At least six of the eight reported deaths occurred in persons affected by outbreaks caused by Legionella. Hotels were the leading setting, associated with 157 (32%) of the 493 outbreaks. Overall, the outbreaks had a bimodal temporal distribution: 275 (56%) outbreaks started during June-August and 46 (9%) in March. Assessment of trends in the annual counts of outbreaks caused by Cryptosporidium, Legionella, or Pseudomonas indicate mixed progress in preventing transmission. Pathogens able to evade chlorine inactivation have become leading outbreak etiologies. The consequent outbreak and case counts and mortality underscore the utility of CDC's Model Aquatic Health Code (https://www.cdc.gov/mahc) to prevent outbreaks associated with treated recreational water., Competing Interests: No conflicts of interest were reported.

Background: Poor water quality, one of the leading causes of diarrhea, is an issue for most developing countries. Although the health burden of poor-quality water has been studied extensively, there is a paucity of research regarding the impact of household water treatment (HWT) on children's nutritional status using data from large-scale surveys. In this research, we study the effect of HWT on the nutritional status of primary-aged children in India using a secondary data set consisting of 20,315 children between the ages of 6 and 14 (10,523 males and 9,792 females) in 12,839 households from the second wave of the India Human Development Survey (IHDS-II)., Methods: The IHDS-II is a nationally representative, household-based, comprehensive, and face-to-face survey. Households were selected using stratified random sampling, and a team consisting of one male and one female interviewer visited each household between November 2011 and October 2012. A knowledgeable member, typically the male head of household, was interviewed about the socioeconomic condition of the household. An ever-married woman between the ages of 15 and 49, typically the wife of the male head of household, answered questions related to education and health. The height and weight of all eligible household members were measured by interviewers. Correlation between HWT and nutritional status was computed first, and the estimation of a generalized simultaneous equation model, in which a binary indicator of HWT and other covariates was included, was carried out afterward., Results: Bivariate analysis shows a negative association between the nutritional status of children and HWT. Additionally, findings from the generalized simultaneous equation model demonstrate that HWT increases the probability of producing normal-weighted primary-aged children by 1.7 %, while it decreases the probability of primary-aged children being thin by 2.5% and being severely thin by 1.7% in India., Conclusions: This study indicates that HWT has the potential to advance the nutritional status of primary school-aged children in India.

Bioremediation of arsenic using green technology via microbial enzymes has attracted scientists due to its simplicity and cost effectiveness. Statistical optimization of arsenate bioremediation was conducted by the enzyme arsenate reductase extracted from arsenic tolerant bacterium Pseudomonas alcaligenes. Response surface methodology based on Box-Behnken design matrix was performed to determine the optimal operational conditions of a multivariable system and their interactive effects on the bioremediation process. The highest biosorptive activity of 96.2 µg gm -1 of beads was achieved under optimized conditions (pH = 7.0; As (V) concentration = 1000 ppb; time = 2 h). SEM analysis showed the morphological changes on the surface of enzyme immobilized gluteraldehyde crosslinked Ca-alginate beads. The immobilized enzyme retained its activity for 8 cycles. ANOVA with a high correlation coefficient (R 2 > 0.99) and lower "Prob > F"value (<0.0001) corroborated the second-order polynomial model for the biosorption process. This study on the adsorptive removal of As (V) by enzyme-loaded biosorbent revealed a possible way of its application in large scale treatment of As (V)-contaminated water bodies.

Drinking water treatment plants rely on purification of contaminated source waters to provide communities with potable water. One group of possible contaminants are enteric viruses. Measurement of viral quantities in environmental water systems are often performed using polymerase chain reaction (PCR) or quantitative PCR (qPCR). However, true values may be underestimated due to challenges involved in a multi-step viral concentration process and due to PCR inhibition. In this study, water samples were concentrated from 25 drinking water treatment plants (DWTPs) across the US to study the occurrence of enteric viruses in source water and removal after treatment. The five different types of viruses studied were adenovirus, norovirus GI, norovirus GII, enterovirus, and polyomavirus. Quantitative PCR was performed on all samples to determine presence or absence of these viruses in each sample. Ten DWTPs showed presence of one or more viruses in source water, with four DWTPs having treated drinking water testing positive. Furthermore, PCR inhibition was assessed for each sample using an exogenous amplification control, which indicated that all of the DWTP samples, including source and treated water samples, had some level of inhibition, confirming that inhibition plays an important role in PCR-based assessments of environmental samples. PCR inhibition measurements, viral recovery, and other assessments were incorporated into a Bayesian model to more accurately determine viral load in both source and treated water. Results of the Bayesian model indicated that viruses are present in source water and treated water. By using a Bayesian framework that incorporates inhibition, as well as many other parameters that affect viral detection, this study offers an approach for more accurately estimating the occurrence of viral pathogens in environmental waters., (Published by Elsevier B.V.)

In September 2016, Médecins Sans Frontières responded to a hepatitis E (HEV) outbreak in Chad by implementing water treatment and hygiene interventions. To evaluate the coverage and use of these interventions, we conducted a cross-sectional study in the community. Our results showed that 99% of households interviewed had received a hygiene kit from us, aimed at improving water handling practice and personal hygiene and almost all respondents had heard messages about preventing jaundice and handwashing. Acceptance of chlorination of drinking water was also very high, although at the time of interview, we were only able to measure a safe free residual chlorine level (free chlorine residual (FRC) ≥0.2 mg/L) in 43% of households. Households which had refilled water containers within the last 18 hours, had sourced water from private wells or had poured water into a previously empty container, were all more likely to have a safe FRC level. In this open setting, we were able to achieve high coverage for chlorination, hygiene messaging and hygiene kit ownership; however, a review of our technical practice is needed in order to maintain safe FRC levels in drinking water in households, particularly when water is collected from multiple sources, stored and mixed with older water.

Contaminated reclaimed wastewater has the potential to induce adverse effects on the health of wastewater workers and residents. However, few studies have focused on these health risks. In this study, we assessed the health risk of samples collected from different treatment processing units used in a typical water reclamation plant in Nanjing, China. Chemical analysis revealed that 40 semi-volatile organic compounds (SVOCs) and 6 N-nitrosamines (NAs) persisted after wastewater treatment. A health risk assessment revealed that the SVOCs in effluents pose negligible non-carcinogenic risk to wastewater workers and local residents as both the hazard quotient (HQ) and hazard index (HI) were all below 1.00. However, polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs) and NAs may present a carcinogenic risk, since their risk index via dermal exposure exceeded the safety limit (1.00×10 6 ), indicating that conventional treatment processes cannot effectively reduce the health risk in reclaimed wastewater. These results strongly suggest the need for the introduction of advanced treatment technologies capable of effectively removing SVOCs and NAs in water reclamation plants., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Many wastewater treatment technologies have been shown to remove bacterial pathogens more effectively than viral pathogens and, in aquatic environments, levels of traditional faecal indicator bacteria (FIB) do not appear to correlate consistently with levels of human viral pathogens. There is, therefore, a need for novel viral indicators of faecal pollution and surrogates of viral pathogens, especially given the increasing importance of indirect and direct wastewater reuse. Potential candidates include bacteriophages (phages) and the study described here sought to elucidate the relationship between three groups of phages (somatic coliphages (SOMPH), F-RNA coliphages (F-RNAPH) and human-specific phages infecting B. fragilis (Bf124PH) - enumeration using double layer agar technique) and viral pathogens (human adenovirus (HuAdV) and norovirus (NoV) - enumeration using molecular methods) through full-scale municipal wastewater treatment processes. FIB (faecal coliforms (FC) and intestinal enterococci (ENT) - enumeration using membrane filtration) were also monitored. Samples were collected every fortnight, during a twelve-month period, at each stage of four full-scale wastewater treatment plants (WWTP) in southern England (two activated sludge (AS) and two trickling filter (TF) plants) (n = 360 samples). FIB and SOMPH were consistently found in all samples tested, whereas F-RNAPH, Bf124PH and HuAdV were less frequently detected, especially following AS treatment. The detection rate of NoV was low and consequently discussion of this group of viruses is limited. Concentrations of SOMPH and FIB were statistically higher (p value < 0.05) than concentrations of F-RNAPH, Bf124PH and HuAdV in raw wastewater. FIB were more effectively removed than phages in both systems. Removal rates of HuAdV were similar to those of phages at the secondary treatment stage of both systems. In TF systems, HuAdV were removed at the same rate as F-RNAPH, but at lower rates than SOMPH and Bf124PH. The findings suggest that phages (in particular SOMPH) are better indicators of the fate of viral pathogens in WWTP than existing FIB and that these organisms may have a useful role to play in future sanitation safety planning., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In order to optimize drinking water production operation, membrane users can use several analytical tools that help membrane fouling prediction and alleviate fouling by a proper feed water resource selection. However, during strong fouling event, membrane decision-makers still face short-term deadline to decide between different options (e.g. optimization of pretreatment or change in feed water quality). Hence, statistical approach might help to better select the most relevant analytical parameter related to fouling potential of a specific resource in order to speed-up decision taking. In this study, the physical and chemical properties and the filtration performances (at lab-scale) of five ground water resources, selected as potential resources of a large drinking production site of Paris (France), was evaluated through one year. Principal component analysis emphasizes the strong link between waters' organic matrix and fouling propensity. Cluster analysis of filtration performances allowed classifying the water samples into three groups exhibiting strong, low and intermediate fouling. Finally, multiple linear regressions performed on all collected data indicated that strong fouling events were related to a combined increase of carbon content and protein like-substances while intermediate fouling might only be anticipated by an increase of fluorescence signal associated to protein like-substances. This study demonstrates that advanced data analysis might be a powerful tool to better manage water resources selection used for drinking water production and to forecast filtration performances in a context of water quality degradation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Allium cepa assay was carried out in this study to evaluate genotoxic effects of raw and treated water samples from Perak River in Perak state, Malaysia. Samples were collected from three surface water treatment plants along the river, namely WTPP, WTPS, and WTPK. Initially, triplicates of equal size Allium cepa (onions) bulbs, 25-30 mm in diameter and average weight of 20 g, were set up in distilled water for 24 h at 20 ± 2 °C and protected from direct sunlight, to let the roots to grow. After germination of roots (0.5-1.0 cm in length), bulbs were transferred to collected water samples each for a 96-h period of exposure. The root physical deformations were observed. Genotoxicity quantification was based on mitotic index and genotoxicity level. Statistical analysis using cross-correlation function for replicates from treated water showed that root length has inverse correlation with mitotic indices (r = - 0.969) and frequencies of cell aberrations (r = - 0.976) at lag 1. Mitotic indices and cell aberrations of replicates from raw water have shown positive correlation at lag 1 (r = 0.946). Genotoxicity levels obtained were 23.4 ± 1.98 (WTPP), 26.68 ± 0.34 (WTPS), and 30.4 ± 1.13 (WTPK) for treated water and 17.8 ± 0.18 (WTPP), 37.15 ± 0.17 (WTPS), and 47.2 ± 0.48 (WTPK) for raw water. The observed cell aberrations were adherence, chromosome delay, C-metaphase, chromosome loss, chromosome bridge, chromosome breaks, binucleated cell, mini cell, and lobulated nuclei. The morphogenetic deformations obtained were likely due to genotoxic substances presence in collected water samples. Thus, water treatment in Malaysia does not remove genotoxic compounds.

This study examines the feasibility of a novel nanofiltration membrane bioreactor (NF-MBR) followed by reverse osmosis (RO) process for water reclamation at 90% recovery and using an ultrafiltration MBR (UF-MBR)+RO as baseline for comparison. Both MBRs adopted the same external hollow fiber membrane configurations and operating conditions. The collected permeates of the MBRs were subsequently fed to the respective RO systems. The results showed that the NF-MBR (operated at a constant flux of 10 L/m 2 h) achieved superior MBR permeate quality due to enhanced biodegradation and high rejection capacity of the NF membrane, leading to lower RO fouling rates (∼3.3 times) as compared to the UF-MBR. Further analysis indicated that the cake layer fouling that caused the cake-enhanced osmotic pressure (CEOP) effect contributed predominantly to the transmembrane pressure (TMP) increase in the NF-MBR, while irreversible pore fouling was the major reason for UF membrane fouling. Furthermore, it was found that the biopolymers (i.e., organics with MW > 10 kDa) were the main components present in the foulants of the NF/UF membranes and RO membranes. The analysis indicated that the NF-MBR + RO system at recovery of 90% has comparable energy consumption as the UF-MBR + RO system at recovery of 75%. Our findings proved the feasibility of the NF-MBR + RO for water reclamation at a high recovery rate., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In arid environmental regions, such as the Kingdom of Saudi Arabia (KSA), each and every drop of groundwater needs to be efficiently utilized to meet growing water demands. Ground water treatment plants (WTPs) are regularly being monitored by the municipalities to ensure safe water supply. However, analyzing large data to assess the performance of a WTP has always been a daunting task for plant's management. Most of existing performance assessment frameworks were developed for surface WTPs. In this research, an assessment framework using performance-based water quality indices (P WQI ) is developed to facilitate senior management of ground WTPs for effective decision-making. The framework is also implemented on a case study of Buraydah, Qassim, Saudi Arabia. Five most important water quality parameters (WQPs) have been selected to assess the performance of different components of the WTP, including raw water, pre-treatment, ultrafiltration, sand filtration, reverse osmosis, and final product. Depending on the relative importance of WQPs for a specific treatment process, different weighting schemes have been developed for each treatment process using fuzzy analytical hierarchical process (FAHP) to address the possible uncertainties in data and imprecision in expert opinion. Subsequently, fuzzy weighted sum method (FWSM) is employed to develop aggregated P WQI for assessing average monthly performance during the year 2016. Study results show that all the units consistently performed "high," and the plant is meeting drinking water quality standards throughout the year. Hypothetical scenario analysis revealed robustness of the developed framework by showing lacking performance in case failure of different units.

An investigation was conducted for 20 different types of sludge in order to identify the key organic compounds in extracellular polymeric substances (EPS) that are important in assessing variations of sludge filterability. The different types of sludge varied in initial total solids (TS) content, organic composition and pre-treatment methods. For instance, some of the sludges were pre-treated by acid, ultrasonic, thermal, alkaline, or advanced oxidation technique. The Pearson's correlation results showed significant correlations between sludge filterability and zeta potential, pH, dissolved organic carbon, protein and polysaccharide in soluble EPS (SB EPS), loosely bound EPS (LB EPS) and tightly bound EPS (TB EPS). The principal component analysis (PCA) method was used to further explore correlations between variables and similarities among EPS fractions of different types of sludge. Two principal components were extracted: principal component 1 accounted for 59.24% of total EPS variations, while principal component 2 accounted for 25.46% of total EPS variations. Dissolved organic carbon, protein and polysaccharide in LB EPS showed higher eigenvector projection values than the corresponding compounds in SB EPS and TB EPS in principal component 1. Further characterization of fractionized key organic compounds in LB EPS was conducted with size-exclusion chromatography-organic carbon detection-organic nitrogen detection (LC-OCD-OND). A numerical multiple linear regression model was established to describe relationship between organic compounds in LB EPS and sludge filterability., (Copyright © 2016 Elsevier Ltd. All rights reserved.)