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An organometallic dye, europium tetrakis dibenzoylmethide triethylammonium (EuD 4 TEA) and gold nanoparticles (Au NPs) impregnated paper based sensor platform have been utilized for development of fluorescence turn-on cyanide assay in aqueous media. The ordinary filter paper with 6 μ m pore size were employed as solid support that facilitates impregnation of EuD 4 TEA and gold nanoparticles and provides durability. Detection mechanism relying on two processes (i) dissolution of gold nanoparticles causing fluorescence recovery and (ii) ligand exchange of triethyl amine with CN group stimulating cyanide specific fluorescence enhancement. The paper platform exhibit naked eye distinguishable color transition upon CN − addition from 10 −2 to 10 −12 M. To standardize the methodology a homemade image processing algorithm has been developed that enabling calibration of color change and quantify CN − concentration. The described algorithm is applicable to Android smart phones and facilitate transforming these devices into a quantitative cyanide detector. The overall methodology provides instrument free cyanide detection and therefore rapid control of water quality and safety at off-field conditions. [ABSTRACT FROM AUTHOR]

Abstract Over the past 29 years there have been myriad research efforts into the catalytic removal of nitrates from drinking water. In this work, 147 papers published during that period have been examined from the point of view of the ability of catalysis to produce water that is suitable for human consumption as well as amenable to industrial scale-up at reasonable working conditions of temperature and residence time. After close examination of the aforementioned articles, it is evident that this methodology has fulfilled only half its aims: it is able to reduce the nitrate concentration to guideline levels for human consumption, but it inevitably produces concentrations of ammonia and nitrites that are beyond the accepted limits for safe consumption of water. It is sometimes recommended that catalysis be combined with an ancillary technique, such as adsorption, in order to eliminate the undesirable byproducts mentioned above. However, this implies resorting to extra treatment units at the industrial scale, thus making the whole treatment process more complex and expensive. Our conclusion is that the effective catalytic removal of nitrates from drinking water is a very difficult problem. Highlights • 147 papers on catalytic removal of nitrates from drinking water have been examined. • No catalyst has been found to simultaneously decrease nitrate, nitrite and ammonia. • To transfer this lab technique to purify water to a realistic situation, is difficult. • The catalytic removal of nitrates from drinking water is still an unresolved problem. [ABSTRACT FROM AUTHOR]

A number of physical, chemical and biological water quality parameters are measured to understand quality conditions of a riverine environment. Various aggregation techniques have been used to reflect the combined effect of the existing or proposed quality levels. Water Quality Index (WQI) has been developed primarily for fresh water environments. Organic pollutants are not considered in many WQIs because analyses of organics are rather expensive. In general, fecal coliform and total coliform counts are measured to reflect biological contamination of water. With growing consensus on considering rivers as ecological entity, rather than merely a source of water for human consumptions, the emphasis is changing from water quality index (WQI) to River Health Index (RHI). As benthic macroinvertebrate species are differentially sensitive to many biotic and abiotic factors in river environment, macroinvertebrate community structure has commonly been used as indicator of stream water condition. A number of river health assessment methodologies have been proposed in past and several indices such as Ecological Health Index (EHI), Ecological Quality Index (EQI), Overall Index of Pollution (OIP) and River Pollution Index (RPI) have been developed using water quality variables and aquatic species for evaluating the ecological health of river systems. This paper attempts to review and summarize some of these indices with particular emphasis on measurable parameters included in such formulations. The analyses suggest that with sufficient scientific experience and understanding in this area, it is possible to define a River Health Index (RHI) by including algae, macroinvertebrates and fish species as measurable parameters along with routine physico-chemical characteristics of river water. One such formulation on RHI has been proposed by the authors in this paper. The novelty of the proposed formulation include simple calculations and presentation of RHI value on 0–100 scale. The biological indices used in ACEDP (2011) requires biological expertise which is not normally available with water resource managers. Hence species identification and counting based simple biotic indices have been proposed so that it can be easily done by non experts also. River Health Level (RHL) can be categorized as ‘critical’ or ‘excellent’ based on RHI value <=20 or >80. Thus RHI values can be used to identify the healthy or unhealthy stretches of the river. RHI can serve as scientific tool to assess the current status, need and effectiveness of any intervention required to improve the condition of the river. Application of this RHI formulation on main stream of river Ganga (India) is under study. [ABSTRACT FROM AUTHOR]

The paper presents results of a follow-up to an earlier study which established a geospatial link between naturally elevated uranium (U) levels in borehole water and haematological abnormalities in local residents serving as a proxy for leukaemia prevalent in the area. While the original study focussed on drinking water only, this paper also explores alternative exposure pathways including the inhalation of dust and the food chain. U-levels in grass and tissue of sheep generally reflect U-levels in nearby borehole water and exceed background concentrations by 20 to nearly 500 times. U-levels in sheep tissue increase with age of the animal. Wool showed the highest U-concentration followed by other non-consumable tissue such as hooves, teeth and bones. Lower levels occur in edible parts such as meat and inner organs. The U-deposition rate in wool is several orders of magnitudes higher than in bone as a known target organ. Wool is an easy-to-sample non-invasive bioindicator for U-levels in meat. Depending on the original water content, dried samples show up to 5 times higher U-levels than identical fresh material. Contaminated drinking water is the main exposure pathway for farm residents resulting in U-uptake rates exceeding the WHO's tolerable daily intake (TDI) limit by up to 900%. This is somewhat mitigated by the fact that U-speciation is dominated by a neutral calcium-uranyl-carbonate complex of relatively low toxicity. Commercially available household filters are able to significantly reduce U-levels in well water and are thus recommended as a short-term intervention. Based on average consumption rates sheep meat, as local staple food, accounts for 34% of the TDI for U. Indoor levels of radon should be monitored, too, since it is linked to both, U and leukaemia. With elevated U-levels being present in other geological formations across South Africa boreholes in these areas should be surveyed. [ABSTRACT FROM AUTHOR]

Abstract: Human error contributes to one of the major causes of the prevalence of drinking water contamination incidents. It has, however, attracted insufficient attention in the cleaner production management community. This paper analyzes human error appearing in each stage of the gestation of 40 drinking water incidents and their causes, proposes resilience-based mechanisms and tools within three groups: consumers, drinking water companies, and policy regulators. The mechanism analysis involves concepts and ideas from behavioral science, organizational culture, and incentive analysis. Determinants for realizing cleaner drinking water system are identified. Future efforts and direction for embedding resilience into drinking water risk management are suggested. This paper contributes to identifying a framework and determinants of resilience-oriented management mechanisms for cleaner drinking water supply, and, is essential for ensuring the successful practice of managing drinking water contamination risks. It harmonizes the two fields of risk management and resilience thinking, and provides a new insight for implementing effective actions in drinking water-related sectors. [Copyright &y& Elsevier]

Disinfection for the supply of safe drinking water forms a variety of known and unknown byproducts through reactions between the disinfectants and natural organic matter. Chronic exposure to disinfection byproducts through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. Since their discovery in drinking water in 1974, numerous studies have presented models to predict DBP formation in drinking water. To date, more than 48 scientific publications have reported 118 models to predict DBP formation in drinking waters. These models were developed through laboratory and field-scale experiments using raw, pretreated and synthetic waters. This paper aims to review DBP predictive models, analyze the model variables, assess the model advantages and limitations, and to determine their applicability to different water supply systems. The paper identifies the current challenges and future research needs to better control DBP formation. Finally, important directions for future research are recommended to protect human health and to follow the best management practices. [Copyright &y& Elsevier]

Negotiation and active involvement with participation of water managers, experts, stakeholders and representatives of the general public requires decision support tools (Environmental Decision Support Systems; EDSS) that build on transparency and flexibility in order to reach sound action plans and management instruments. One possible EDSS for active involvement of stakeholders is application of Bayesian networks (Bns). The paper gives an example of a case study (The Danish case) where farmers and hydrologists disputed the degree to which pesticide application affected the quality of deep groundwater. Instead of selecting one opinion or another, the decision was made to include both in the Bns. By adopting this approach, it was possible to view the results from either point of view, accepting the reality of the situation, not becoming mired in an insoluble conflict, and in this way laying the foundation for future compromises. The paper explores Bns as a tool for acting on and dealing with management of groundwater protection. Bns allow stakeholders'' divergent values, interests and beliefs to be surfaced and negotiated in participatory processes for areas where conventional physically based groundwater models are insufficient due to lack of data, physical understanding, flexibility or lack of integration capability. In this way, the agency will be able to address the institutional arrangement influencing groundwater protection in all its complexity. [Copyright &y& Elsevier]

Disinfection for drinking water reduces the risk of pathogenic infection but may pose chemical threat to human health due to disinfection residues and their by-products (DBPs) when the organic and inorganic precursors are present in water. More than 250 DBPs have been identified, but the behavioural profile of only approximately 20 DBPs are adequately known. In the last 2 decades, many modelling attempts have been made to predict the occurrence of DBPs in drinking water. Models have been developed based on data generated in laboratory-scaled and field-scaled investigations. The objective of this paper is to review DBPs predictive models, identify their advantages and limitations, and examine their potential applications as decision-making tools for water treatment analysis, epidemiological studies and regulatory concerns. The paper concludes with a discussion about the future research needs in this area. [Copyright &y& Elsevier]

In nature, arsenic is mostly found in the form of inorganic compounds. Inorganic arsenic compounds have a variety of uses and are currently used in the manufacture of pesticides, preservatives, pharmaceuticals, etc. While inorganic arsenic is widely used, arsenic pollution is increasing worldwide. Public hazards caused by arsenic contamination of drinking water and soil are becoming increasingly evident. Epidemiological and experimental studies have linked inorganic arsenic exposure to the development of many diseases, including cognitive impairment, cardiovascular failure, cancer, etc. Several mechanisms have been proposed to explain the effects caused by arsenic, such as oxidative damage, DNA methylation, and protein misfolding. Understanding the toxicology and potential molecular mechanisms of arsenic can help mitigate its harmful effects. Therefore, this paper reviews the multiple organ toxicity of inorganic arsenic in animals, focusing on the various toxicity mechanisms of arsenic-induced diseases in animals. In addition, we have summarized several drugs that can have therapeutic effects on arsenic poisoning in pursuit of reducing the harm of arsenic contamination from different pathways. • Inorganic arsenic exposure can cause toxic damage to multiple organ systems in animals. • Oxidative stress, DNA damage, cell cycle disruption, inflammation and immune imbalance are the main toxic mechanisms of arsenic. • Curcumin, selenium, N -acetylcysteine, melatonin, and propolis are all effective against arsenic toxicity. [ABSTRACT FROM AUTHOR]

Municipal solid waste management (MSWM) has always been a typical issue in India. The rapid population growth, impetuous adoption of modern lifestyle, and fast urbanization resulted in India's swift generation of complicated municipal solid waste (MSW). Consequently, municipalities of different cities in India face various difficulties in MSW collection, treatment and disposal methodology. Inefficient or poorly managed MSW causes numerous troubles, including air pollution, soil fouling, contamination in drinking water and health hazard, and it also impacts socio-economic deterioration. MSWM technique selection is based on several criteria, which are generally imprecise, uncertain, and vague. This paper uses the cubic Pythagorean fuzzy number to comprise the fuzzy characteristics of the criteria value concerning the five alternatives (Thermochemical methods in MSW treatment and disposal). The best MSW treatment and disposal method is selected amongst the five alternatives under the novel multi-criteria group decision-making (MCGDM) approach, the cubic Pythagorean fuzzy EDAS (Evaluation based on Distance from Average Solution) in the Indian context. The weight information of the criteria has yet to be wholly known. A non-linear optimization scheme is proposed to determine the criteria weights that are partially known to maximize the generalized total distance measure between alternatives corresponding to all criteria. The present method is explained with a case study. Finally, a comparative analysis is drawn between the present and some existing methods, showing that the present method is consistent and robust enough to apply in practice. • CuPyF extended EDAS approach is developed for solving MCGDM problems. • Optimization model is applied for computing incomplete weights. • Create an algorithm for MCGDM problems using the CuP-EDAS technique. • A case study for municipal solid waste management is considered for recycling. • Sensitivity and comparative analysis are verified to validate the results. [ABSTRACT FROM AUTHOR]

While infrastructure is often understood to operate 'in the background', scholars have increasingly attended to the labour that enables urban material flows. Drawing on empirical material collected through fieldwork and document analysis in Lilongwe, this paper explores how different residents of the city experience and respond to the regular failures of infrastructure. We examine sanitation in one middle- and two low-income areas, considering the contamination of drinking water and the collapse of latrines. Attending to the gendered, embodied, affective, and intimate dimensions of maintenance and repair labours, we develop three interrelated arguments. First, we frame incidents of failure not as individual accidents but as part of persistently fragile infrastructures. Second, we contribute to extending the gaze of infrastructural labours beyond manual work and 'expert' knowledge to consider a range of unpaid practices and their role in preventing, responding to, and being impacted by failure. Finally, we show that both the labour and impacts of infrastructural failure disproportionally fall on (low-income) women. Emphasising the ongoing, gendered struggles of keeping sanitation infrastructures functional helps us to see the limits of scholarship that centres clearly identifiable jobs associated with infrastructure's construction, maintenance and repair. We conclude with reflections on the implications of these arguments for our understanding of the knowledges and labours that keep infrastructures working, and the conditions in which these are performed. [ABSTRACT FROM AUTHOR]

The continuously increasing presence of micro- and nanoplastics contamination in numerous food products for human consumption is threatening and their potential health effects towards humans remain uncertain. At present, investigations on packaged beverages (e.g. bottled drinking water, beer, milk and refreshments) have received scientific attention and represent an important part of microplastic research as humans are orally exposed to these anthropogenic contaminants every day. Rapid and effective detection methods are important to quantify micro- and nanoplastic particles with a great accuracy as well as to identify their sources and characteristics. A number of methods are currently in use to assess microplastics in packaged beverages; however, the great variations in methods and data acquisition render difficulties when comparing the results and developing the protocols. Based on the challenges, this paper aims to provide a comprehensive understanding of emerging technological approaches, points out the current limitations from sample preparation to quantification and present recommendations. From the results of our analysis, we postulate an example framework that can be applied to different types of drinking products for investigating micro- and nanoplastics. Overall, this review will serve as a first step towards harmonization of micro- and nanoplastic monitoring efforts and a point of reference to help direct future researches focusing on drinking products intended for human consumption. Image 1 • Analytical methods for detecting microplastics in commercial drinking products are critically reviewed. • Methods vary greatly with respect to the type of drinking products and of geographical region. • Microplastics were most studied in bottled water, followed by beer, milk and refreshments. • Illustrated example workflow provides a first step towards harmonization of methods to investigate micro- and nanoplastics. This paper focuses on adopting a unified approach towards determination and characterization of micro (nano)plastics on packaged beverages by critically summarizing the available literature information of detection, analysis and methods regarding microplastic contamination including; drinking water, beer, milk and other refreshments, along with describing an example framework to provide a guideline for further research. [ABSTRACT FROM AUTHOR]

In order to counter growing shortages in water supply, there has been an increasing adoption of non-conventional sources, such as desalination. As a matter of fact, the marginal costs of water ( i.e. , production) or, in a different perspective, the potential and limitations of different technologies, make the use of particular types of desalination methods an increasing possibility. The growing use of hybrid systems highlights the acknowledgment of those technologies as accepted opportunities to diversify water sources, and from a different perspective, render desalination solutions more efficient and effective. Thus, the study of cost determinants which confer a dynamic importance to such technologies is paramount and policy relevant. For that purpose, cost structures and cost determinants were standardized in order to provide guidelines, or a basis, for a suitable cost perception. This paper provides relevant insights of desalination projects’ key factors, and to such an extent, this is a significant contribution. In this analysis, the results achieved compare possible energy solutions, mainly targeting renewable prospects, due to their impact on the total cost of produced water. The economic feasibility of different desalination technologies and energy solutions is also assessed, with a significant focus on possible hybrid possibilities and the site-specificity of such projects, due to their importance and impact on future technology trends and their cost variations. [ABSTRACT FROM AUTHOR]

Since Flint returned to its pre-crisis source of drinking water close to 25,000 water samples have been collected and tested for lead and copper in > 10,000 residences. This paper presents the first analysis and time trend modeling of lead data, providing new insights about the impact of this intervention. The analysis started with geocoding all water lead levels (WLL) measured during an 11-month period following the return to the Detroit water supply. Each data was allocated to the corresponding tax parcel unit and linked to secondary datasets, such as the composition of service lines, year built, or census tract poverty level. Only data collected on residential parcels within the City limits were used in the analysis. One key feature of Flint data is their collection through two different sampling initiatives: (i) voluntary or homeowner-driven sampling whereby concerned citizens decided to acquire a testing kit and conduct sampling on their own (non-sentinel sites), and (ii) State-controlled sampling where data were collected bi-weekly at selected sites after training of residents by technical teams (sentinel sites). Temporal trends modeled from these two datasets were found to be statistically different with fewer sentinel data exceeding WLL thresholds ranging from 10 to 50 μg/L. Even after adjusting for housing characteristics the odds ratio (OR) of measuring WLL above 15 μg/L at non-sentinel sites is significantly > 1 (OR = 1.480) and it increases with the threshold (OR = 2.055 for 50 μg/L). Joinpoint regression showed that the city-wide percentage of WLL data above 15 μg/L displayed four successive trends since the return to Detroit Water System. Despite the recent improvement in water quality, the culprit for differences between sampling programs needs to be identified as it impacts exposure assessment and might influence whether there is compliance or not with the Lead and Copper Rule. [ABSTRACT FROM AUTHOR]

Studies have yet to evaluate the effects of water improvement on fluoride concentrations in drinking water and the corresponding health risks to Chinese residents in endemic fluorosis areas (EFAs) at a national level. This paper summarized available data in the published literature (2008–2016) on water fluoride from the EFAs in China before and after water quality was improved. Based on these obtained data, health risk assessment of Chinese residents' exposure to fluoride in improved drinking water was performed by means of a probabilistic approach. The uncertainties in the risk estimates were quantified using Monte Carlo simulation and sensitivity analysis. Our results showed that in general, the average fluoride levels (0.10–2.24 mg/L) in the improved drinking water in the EFAs of China were lower than the pre-intervention levels (0.30–15.24 mg/L). The highest fluoride levels were detected in North and Southwest China. The mean non-carcinogenic risks associated with consumption of the improved drinking water for Chinese residents were mostly accepted (hazard quotient < 1), but the non-carcinogenic risk of children in most of the EFAs at the 95th percentile exceeded the safe level of 1, indicating the potential non-cancer-causing health effects on this fluoride-exposed population. Sensitivity analyses indicated that fluoride concentration in drinking water, ingestion rate of water, and the exposure time in the shower were the most relevant variables in the model, therefore, efforts should focus mainly on the definition of their probability distributions for a more accurate risk assessment. [ABSTRACT FROM AUTHOR]

Waterborne outbreaks of gastrointestinal diseases are of great concern to drinking water producers and can give rise to substantial costs to the society. The World Health Organisation promotes an approach where the emphasis is on mitigating risks close to the contamination source. In order to handle microbial risks efficiently, there is a need for systematic risk management. In this paper we present a framework for microbial risk management of drinking water systems. The framework incorporates cost-benefit analysis as a decision support method. The hydrological Soil and Water Assessment Tool (SWAT) model, which was set up for the Stäket catchment area in Sweden, was used to simulate the effects of four different mitigation measures on microbial concentrations. The modelling results showed that the two mitigation measures that resulted in a significant (p < 0.05) reduction of Cryptosporidium spp. and Escherichia coli concentrations were a vegetative filter strip linked to cropland and improved treatment (by one Log10 unit) at the wastewater treatment plants. The mitigation measure with a vegetative filter strip linked to grazing areas resulted in a significant reduction of Cryptosporidium spp., but not of E. coli concentrations. The mitigation measure with enhancing the removal efficiency of all on-site wastewater treatment systems (total removal of 2 Log10 units) did not achieve any significant reduction of E. coli or Cryptosporidiu m spp. concentrations. The SWAT model was useful when characterising the effect of different mitigation measures on microbial concentrations. Hydrological modelling implemented within an appropriate risk management framework is a key decision support element as it identifies the most efficient alternative for microbial risk reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • HFPNM undergoes fluorescence quenching upon contact with Cu2+. • HFPNM is capable of accurately detecting 100–1000 nmol/L of Cu2+. • HFPNM can still be used as a Cu2+ sensor after 5 cycles of use. • HFPNM have the advantages of high detection sensitivity and environmental friendliness for recycling compared to other Cu2+ sensors. Cu2+ contamination in drinking water poses a threat to humans and the environment, and high concentrations of Cu2+ in human blood can induce disease. In recent years, fluorescence sensing of Cu2+ prepared from rare earth elements has been widely used for the accurate detection and quantification of Cu2+. In this paper, we report that europium (Eu), 4,4′,4-trimethyltriphenylamine (TTA), and 1,10-phenanthroline (Phen) undergo a complexation reaction to form the Eu(TTA) 3 Phen complex, which is loaded on SiO 2 nanoparticle to form SiO 2 @Eu3+. We use electrospinning of SiO 2 @Eu3+ and polyacrylonitrile (PAN) co-blended solutions to prepare PAN fluorescent nanofiber membranes (FPNM). FPNM are hydrolyzed hydrolysis to obtain Cu2+ sensors (HFPNM). The super hydrophilic surface of HFPNM undergoes fluorescence quenching upon contact with Cu2+. HFPNM is capable of accurately detecting 100–1000 nmol/L of Cu2+. Moreover, EDTA can be used as a reversible on/off switch for detection, and HFPNM can still be used as a Cu2+ sensor after 5 cycles of use. The HFPNM have the advantages of high detection sensitivity and environmental friendliness for recycling compared to other Cu2+ sensors. Fluorescent nanofibers can be combined with bio-nanotechnology allowing for promising future applications in Cu2+ detection and wearable smart fabrics. [ABSTRACT FROM AUTHOR]

Best practice in regulating contaminants of emerging concern (CEC) must involve the integration of science and policy, be defensible and accepted by diverse stakeholders. Key elements of CEC frameworks include identification and prioritisation of emerging contaminants, evaluation of health and environmental impacts from key matrices such as soil, groundwater, surface waters and sediment, assessments of available data, methods and technologies (and limitations), and mechanisms to take cognisance of diverse interests. This paper discusses one of the few frameworks designed for emerging contaminants, the Minnesota Department of Health (MDH) Drinking Water Contaminants of Emerging Concern (CEC) program. Further review of mechanisms for CECs in other jurisdictions reveals that there is only a small number of regulatory and guidance regimes globally. There is also merit in a formal mechanism for the global exchange of knowledge and outcomes associated with CECs of global interest. [ABSTRACT FROM AUTHOR]

The security of drinking water is increasingly being recognized as a major challenge for municipalities and water utilities. In the event of a contamination, water spreads rapidly before the problem is detected. Contaminated drinking water can induce major epidemics, disrupt economic life and create mass panics. SAFEWATER is an EU-funded project that aims at developing a comprehensive event detection and event management solution for drinking water security management. The implemented solution will rely on new and currently existing sensors. A number of innovative software components will capture and analyze the data collected by the sensors, trigger alerts when anomalies are detected, and enable prediction of the contamination spread and its source. A web-based decision support tool will facilitate situation awareness and support the execution of mitigation measures. This paper focuses on the software architecture that enables coordinated operation of the event detection, simulation modules and the decision support application. [ABSTRACT FROM AUTHOR]

Inconsistent use of household water treatment and safe storage (HWTS) systems reduces their potential health benefits. Ultraviolet (UV) disinfection is more convenient than some existing HWTS systems, but it does not provide post-treatment residual disinfectant, which could leave drinking water vulnerable to recontamination. In this paper, using as-treated analyses, we report on the field efficacy of a UV disinfection system at improving household drinking water quality in rural Mexico. We further assess the risk of post-treatment contamination from the UV system, and develop a process-based model to better understand household risk factors for recontamination. This study was part of a larger cluster-randomized stepped wedge trial, and the results complement previously published population-level results of the intervention on diarrheal prevalence and water quality. Based on the presence of Escherichia coli (proportion of households with ≥1 E. coli /100 mL), we estimated a risk difference of −28.0% (95% confidence interval (CI): −33.9%, −22.1%) when comparing intervention to control households; −38.6% (CI: −48.9%, −28.2%) when comparing post- and pre-intervention results; and −37.1% (CI: −45.2%, −28.9%) when comparing UV disinfected water to alternatives within the household. We found substantial increases in post-treatment E. coli contamination when comparing samples from the UV system effluent (5.0%) to samples taken from the storage container (21.1%) and drinking glasses (26.0%). We found that improved household infrastructure, additional extractions from the storage container, additional time from when the storage container was filled, and increased experience of the UV system operator were associated with reductions in post-treatment contamination. Our results suggest that the UV system is efficacious at improving household water quality when used as intended. Promoting safe storage habits is essential for an effective UV system dissemination. The drinking glass appears to represent a small but significant source of recontamination that is likely to impact all HWTS systems. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are persistent, mobile, and toxic chemicals that are hazardous to human health and the environment. Several countries, including the United States, plan to set an enforceable maximum contamination level for certain PFAS compounds in drinking water sources. Among the available treatment options, photocatalytic treatment is promising for PFAS degradation and mineralization in the aqueous solution. In this review, recent advances in the abatement of PFAS from water using photo-oxidation and photo-reduction are systematically reviewed. Degradation mechanisms of PFAS by photo-oxidation involving the holes (h vb + ) and oxidative radicals and photo-reduction using the electrons (e cb - ) and hydrated electrons (e aq - ) are integrated. The recent development of innovative heterogeneous photocatalysts and photolysis systems for enhanced degradation of PFAS is highlighted. Photodegradation mechanisms of alternative compounds, such as hexafluoropropylene oxide dimer acid (GenX) and chlorinated polyfluorinated ether sulfonate (F-53B), are also critically evaluated. This paper concludes by identifying major knowledge gaps and some of the challenges that lie ahead in the scalability and adaptability issues of photocatalysis for natural water treatment. Development made in photocatalysts design and system optimization forges a path toward sustainable treatment of PFAS-contaminated water through photodegradation technologies. [Display omitted] • Degradation mechanisms of PFAS by photo-oxidation and photo-reduction processes are discussed in detail. • Innovative heterogeneous photocatalysts and photolysis systems for enhanced degradation of PFAS are highlighted. • Advancements on the photodegradation of PFAS alternatives are emphasized. • Major knowledge gaps in the PFAS photodegradation are identified. [ABSTRACT FROM AUTHOR]

Galvanic corrosion is one of the main reasons for pipe degradation and lead contamination in drinking water systems. The electrical connection of dissimilar metals in corrosive tap water accelerates the dissolution rate of lead from leaded materials. This paper reports an electrochemistry based model to predict lead leaching from a copper pipe fitted with leaded connections. The corrosion of lead at the metal-electrolyte interface depends on the charge transfer and the electric field across the interface. The electric potential field and the mass transport process are dynamically coupled for corrosion propagation in stagnant water; they are respectively governed by the conservation of charge and reactant mass. Using polarization parameters for the electrodes as a function of concentration of oxidizing agents, a dynamic electrochemical model is developed to predict lead leaching from galvanic corrosion. The predicted lead and copper leaching curves are in good agreement with the experimental data for a lead-soldered coupled copper pipe, a brass valve coupled copper pipe, and a pure copper pipe. The findings offer a quantitative understanding on galvanic corrosion in drinking water supply systems and a practical modeling framework for prediction of lead leaching in tap water as a function of stagnation time. [Display omitted] • Time evolution of 3d (axisymmetric) electric potential and reactant concentration fields. • Prediction of lead leaching curve in drinking water pipe from basic electrochemical principles. • Determination of polarization parameters of galvanic pairs. [ABSTRACT FROM AUTHOR]

Addressing the issue of agricultural pollution in water protection areas (WPA) requires assessing the impact of agricultural activities at regional scales. However, current water quality modeling studies often neglect the agronomic concept of a cropping system and interactions with soils. This paper presents a participatory assessment framework involving local experts in building a shared diagnosis of nitrate losses from cropping systems in a WPA. It includes a co-designed typology of landscape units and participatory assessment of nitrate losses with the modeling software Syst'N. Results show that characteristics of cropping systems depended on soils and that nitrate losses were highest in shallow soils. Intercrop periods were identified as critical periods for nitrate leaching, which demonstrates the importance of considering pluri-annual crop rotations rather than individual crops. The framework is generic for a modeling approach based on the involvement of local experts, who define their functional system in an agronomically sound way. [ABSTRACT FROM AUTHOR]

Arsenic contamination of drinking water is a major problem for many people worldwide, especially the inhabitants of Bangladesh and Nepal. Through Dartmouth Humanitarian Engineering (DHE) at Dartmouth College, we are working to create a home-based arsenic filtration system. The ultimate goal of this project is to provide highly effective, reliable and affordable filters for the people affected by this problem in Nepal and other countries. This paper illustrates the purpose of the project, reports results obtained while creating various components of the filer, and discusses future plans to create a fully assembled, deployable prototype. Our current working prototype can get arsenic concentration below the WHO safe drinking limit of 10ppb – specifically to 2.58ppb starting from 260 ppb. [ABSTRACT FROM AUTHOR]

Abstract: The impact on water resources caused by municipal wastewater discharges has become a critical and ever-growing environmental and public health problem. In order to be able to efficiently address this problem, it is important to adopt an integrated approach that includes a decrease in and control of contamination at its source. These principles have been successfully applied in the industrial sector and now these concepts are also being applied to integrated water resources management. In this context the conceptual model of the Three Steps Strategic Approach (3-SSA) was developed, consisting of: 1) minimization and prevention, 2) treatment for reuse and 3) stimulated natural self-purification. This paper is focused on the first step. The assessment includes a case study in the expansion area of the city of Cali, Colombia (410,380 new inhabitants). The evaluation of alternatives is done using two different system boundaries: (1) reduction in water supply costs for households, savings associated with the drinking water infrastructure and the avoided costs in the infrastructure of additional sewerage and wastewater treatment facilities; and (2) only taking into account the reduction in water supply costs for households and the savings associated with the drinking water infrastructure. The alternatives of minimization and prevention were hierarchized using an analytic hierarchy process and grey relational analysis. A cost-benefit analysis was carried out to compare the highest ranked alternatives with the conventional approach, which considers a ‘business as usual scenario’ of high water use, end-of-pipe wastewater treatment plant and the conventional water supply system with drinking water quality for all uses. The best minimization and prevention alternatives for Cali's expansion zone were found to be those which consider dual flush toilets and the possibility of using rainwater harvesting for laundry purposes. However, the minimization and prevention alternatives considered are only viable if these are implemented in more than 20% of household units. [Copyright &y& Elsevier]

Abstract: Water is vital to humans and each of us needs at least 1.5L of safe water a day to drink. Beginning as long ago as 1958 the World Health Organization (WHO) has published guidelines to help ensure water is safe to drink. Focused from the start on monitoring radionuclides in water, and continually cooperating with WHO, the International Standardization Organization (ISO) has been publishing standards on radioactivity test methods since 1978. As reliable, comparable and ‘fit for purpose’ results are an essential requirement for any public health decision based on radioactivity measurements, international standards of tested and validated radionuclide test methods are an important tool for production of such measurements. This paper presents the ISO standards already published that could be used as normative references by testing laboratories in charge of radioactivity monitoring of drinking water as well as those currently under drafting and the prospect of standardized fast test methods in response to a nuclear accident. [Copyright &y& Elsevier]

Abstract: Cryptosporidium parvum (C. parvum), an organism of increasing importance in drinking water, spreads to the environment through faeces of infected animals and humans. C. parvum produces infective chlorine-resistant oocyst that are removed from contaminated raw waters primarily using physical methods such as entrapment in surface or depth bed filters and coagulation–flocculation. In this paper, the aggregation properties of gamma-irradiated C. parvum oocysts in dilute concentrations, as a function of stirring time in the presence of bivalent and trivalent cations were studied. The size and surface charge of C. parvum oocysts were characterized before they were used for aggregation experiments. The surface charge of the oocysts, measured using a zeta potential analyzer were in the range of −57±2mV, which increased to −31±2mV in presence of bivalent electrolytes. Aggregation of oocyst in dilute suspensions was monitored using confocal laser scanning microscope (CLSM) in presence of bivalent or trivalent electrolytes. Aggregation was not visible in the diluted C. parvum oocyst suspension in Milli Q water system in the time frame of the experiment. Addition of a bivalent or trivalent salt with stirring condition induced aggregation due to the suppression of the surface charge of oocysts, resulting in a decrease in the energy of interaction between oocysts, and a decrease in double layer thickness around the oocysts. Predictive models could be built to understand C. parvum oocyst aggregation in raw waters, which could significantly improve the removal of oocysts from untreated (raw) drinking water. [Copyright &y& Elsevier]

Abstract: This paper presents the results of a cytogenetic study conducted among residents of the Techa Riverside communities (Southern Urals, Russia) exposed in the early 1950s as a result of releases of liquid radioactive wastes from the Mayak plutonium-production facility. The study was performed 50–60 years after the beginning of the exposure for those individuals who were predominantly exposed to strontium radioisotopes (89,90Sr) through drinking contaminated river water and consumption of local foodstuff. Standard cytogenetic methods were used for evaluation of the frequency of unstable chromosome aberrations in exposed persons as well as in persons from the control group who were of similar age and sex, living in similar socio-economic conditions in non-contaminated territories of the Southern Urals. The exposure doses were reconstructed for the studied donors using the Techa River Dosimetry System developed in 2009. The doses of internal exposure from ingested radionuclides were evaluated using individual or family in vivo measurements of 90Sr-body burden. Individual cumulative absorbed doses in red bone marrow (RBM) in the studied persons varied in the range of 0.01–4.4Gy. A significantly higher level of unstable chromosome aberrations (UCA) in T-cells was observed in the group of exposed individuals as compared to control group. The highest UCA level was detected in the individuals who were suspected of having chronic radiation syndrome. [Copyright &y& Elsevier]

Summary: The synoptic mass balance approach is often used to evaluate constituent mass loading in streams affected by mine drainage. Spatial profiles of constituent mass load are used to identify sources of contamination and prioritize sites for remedial action. This paper presents a field scale study in which replicate synoptic sampling campaigns are used to quantify the aggregate uncertainty in constituent load that arises from (1) laboratory analyses of constituent and tracer concentrations, (2) field sampling error, and (3) temporal variation in concentration from diel constituent cycles and/or source variation. Consideration of these factors represents an advance in the application of the synoptic mass balance approach by placing error bars on estimates of constituent load and by allowing all sources of uncertainty to be quantified in aggregate; previous applications of the approach have provided only point estimates of constituent load and considered only a subset of the possible errors. Given estimates of aggregate uncertainty, site specific data and expert judgement may be used to qualitatively assess the contributions of individual factors to uncertainty. This assessment can be used to guide the collection of additional data to reduce uncertainty. Further, error bars provided by the replicate approach can aid the investigator in the interpretation of spatial loading profiles and the subsequent identification of constituent source areas within the watershed. The replicate sampling approach is applied to Peru Creek, a stream receiving acidic, metal-rich effluent from the Pennsylvania Mine. Other sources of acidity and metals within the study reach include a wetland area adjacent to the mine and tributary inflow from Cinnamon Gulch. Analysis of data collected under low-flow conditions indicates that concentrations of Al, Cd, Cu, Fe, Mn, Pb, and Zn in Peru Creek exceed aquatic life standards. Constituent loading within the study reach is dominated by effluent from the Pennsylvania Mine, with over 50% of the Cd, Cu, Fe, Mn, and Zn loads attributable to a collapsed adit near the top of the study reach. These estimates of mass load may underestimate the effect of the Pennsylvania Mine as leakage from underground mine workings may contribute to metal loads that are currently attributed to the wetland area. This potential leakage confounds the evaluation of remedial options and additional research is needed to determine the magnitude and location of the leakage. [Copyright &y& Elsevier]

Abstract: The concern on the presence of pesticides in Italian water resources historically broke out around 1980 after severe episodes of ambient, raw water and drinking water contamination due to some herbicides, atrazine (ATR), its metabolites desethylatrazine (DEA) and deisopropylatrazine (DIA), simazine, cyanazine, bentazone, molinate, which affected mainly the maize, grain and rice producing floodplains and karst areas of the northern Regions. Due to the risks of human exposure, in the early 1990 the use of atrazine was banned in Italy and was replaced by terbuthylazine (TERB). In a few years, TERB became a chemical of concern, together with its main metabolite desethylterbuthylazine (DET), because of alerting detections in surface and groundwater resources. Up to now, the risk of contamination of water resources by TERB, DET, DEA and, in some extent ATR, is of relevance in Italy due to their present and past wide employment in agriculture, the discharges or seepages in particularly vulnerable areas, their unfavorable intrinsic properties, e.g. poor sorption and high persistence, their mobility by drift, leaching and runoff in vadose zones, aquifers and surface water. So, unsurprisingly, results from national monitoring of ambient water and raw water indicate that TERB, DET, DEA and residual ATR, despite its withdrawal, are detected at remarkable frequencies and, sometimes, at levels higher than pesticide quality standards under the Italian Decrees for the protection of surface water (specifically, raw waters doomed at the drinking water abstraction), groundwater and drinking water (tap water), that is 0.1–0.5μg/l for individual pesticides and for total pesticides, respectively, including relevant metabolites. On the other hand, in these last years, the control measures in drinking water production adopted by the waterworks Companies and the regional and central health Authorities, also in the view of the recent WHO approaches under the Water Safety Plans, ensure that levels of any pesticide residue (also involving TERB, DET, DEA, ATR) in finished tap water meet parametric values for pesticides. Therefore, in these last years, no derogation to the parametric values for drinking water has been required. The aim of this paper is to contribute to widen the knowledge on the water impact of these important water pollutants giving sound details on present usages, levels and frequencies of detection in water bodies in Italy, on their key chemiodynamic properties, e.g. soil half-lives (DT50) and soil to organic carbon partition (Koc) available in the open literature, particularly for TERB metabolites, and some details on legal provision adopted at the national level. In fact, a more effective protection of water supplies, particularly against TERB and DET, has been pursued in the late 2000s by the Italian Health Ministry through the adoption of consistent provisions aimed at mitigating emissions of TERB in routine agricultural activities, and by the Italian Ministry of the Environment through the adoption of specific Environmental Quality Standards for TERB and its metabolite DET, ATR, SIM for the protection of surface waters. [Copyright &y& Elsevier]

Abstract: This paper presents the concentrations of naturally occurring radionuclides (226Ra, 228Ra and 40K) measured in hand dug wells, boreholes and river waters collected from three oil mineral leases (OML) 30, 58 & 61 oil and gas fields onshore of the Niger delta, using gamma spectroscopy. Fifty-four water samples from the three sources of drinking water supply were collected within the oil fields and host communities and three water samples from a control site. The results showed average activity concentrations of 226Ra, 228Ra and 40K as 8.9 ± 1.0, 8.1 ± 0.9 and 39.8 ± 3.3 respectively for hand dug wells, 4.4 ± 0.8, 4.6 ± 0.5 and 28.5 ± 3.0 for borehole water and 8.2 ± 1.0, 6.7 ± 0.7 and 32.1 ± 3.5 for river water respectively. These 226Ra, 228Ra and 40K average are well above the WHO permissible levels of 1.0, 0.1 and 10 BqL−1 respectively and also above the control values. Although the hazard indices calculated are still within their tolerable levels, the estimated committed effective dose due to intake of the sampled water for all the four age groups considered are far above the ICPR 0.1 mSvyr−1 maximum permissible limit. The result indicates some level of water pollution in the studied area. [Copyright &y& Elsevier]

Abstract: This paper provides a review of recent scientific research on the removal by activated carbon (AC) in drinking water (DW) treatment of 1) two classes of currently unregulated trace level contaminants with potential chronic toxicity—pharmaceutically activate compounds (PhACs) and endocrine disrupting compounds (EDCs); 2) cyanobacterial toxins (CyBTs), which are a group of highly toxic and regulated compounds (as microcystin-LR); and 3) the above mentioned compounds by the hybrid system powdered AC/membrane filtration. The influence of solute and AC properties, as well as the competitive effect from background natural organic matter on the adsorption of such trace contaminants, are also considered. In addition, a number of adsorption isotherm parameters reported for PhACs, EDCs and CyBTs are presented herein. AC adsorption has proven to be an effective removal process for such trace contaminants without generating transformation products. This process appears to be a crucial step in order to minimize PhACs, EDCs and CyBTs in finished DW, hence calling for further studies on AC adsorption removal of these compounds. Finally, a priority chart of PhACs and EDCs warranting further study for the removal by AC adsorption is proposed based on the compounds'' structural characteristics and their low removal by AC compared to the other compounds. [Copyright &y& Elsevier]

Abstract: Lifetime distribution functions and current network age data can be combined to provide an assessment of the future replacement needs for drinking water distribution networks. Reliable lifetime predictions are limited by a lack of understanding of deterioration processes for different pipe materials under varied conditions. An alternative approach is the use of real historical data for replacement over an extended time series. In this paper, future replacement needs are predicted through historical data representing more than one hundred years of drinking water pipe replacement in Gothenburg, Sweden. The verified data fits well with commonly used lifetime distribution curves. Predictions for the future are discussed in the context of path dependence theory. [Copyright &y& Elsevier]

Abstract: Salmonella is one of the leading causes of intestinal illness all over the world as well as the etiological agent of more severe systemic diseases such as typhoid and paratyphoid fevers. While water is known to be a common vehicle for the transmission of typhoidal Salmonella serovars, non-typhoidal salmonellae are mainly known as foodborne pathogens. This paper provides a brief review of the last ten years of peer reviewed publications on the prevalence of Salmonella in natural freshwaters and drinking waters, and on the relevance of these sources for Salmonella dissemination. In industrialized countries, Salmonella was rarely reported in water-borne outbreaks despite it being frequently detected in surface waters including recreational waters and waters used for irrigation or as a drinking water source. Consistent contamination with irrigation waters has been shown to be a common route of crop contamination in produces related Salmonella outbreaks. Multiple drug resistant (MDR) Salmonella strains, that represent an increased hazard for human health and that may contribute to the dissemination of drug resistances were also detected in surface water in developed countries. Surface runoff was shown to play a main role as driver of Salmonella load in surface waters. Accordingly, analysis of serovars indicated a mixed human and animal origin of Salmonella contribution to surface waters, emphasizing the role of wild life animals in water contamination. Data relating to Salmonella prevalence in surface and drinking water in developing countries are quite rare. Nevertheless, data on water-borne outbreaks as well as case control studies investigating the risk factors for endemic typhoid fever confirmed the relevance of water as source for the transmission of this disease. In addition epidemiological studies and Salmonella surveys, consistently provided an undeniable evidence of the relevance of MDR Salmonella Typhi strains in water-borne typhoid fever in developing countries. [Copyright &y& Elsevier]

Abstract: Accidental or intentional drinking water contamination has long been and remains a major threat to water security throughout the world. An inverse problem can be constructed, given sensor measurements in a water distribution system (WDS), to identify the contaminant source characteristics by integrating a WDS simulation model with an optimization method. However, this approach requires numerous compute-intensive simulation runs to evaluate potential solutions; thus, determining the best source characteristic within a reasonable computational time is challenging. In this paper, we describe the development of a WDS contamination characterization algorithm by coupling a statistical model with a heuristic search method. The statistical model is used to identify potential source locations of contamination and a local search aims at further refining contaminant source characteristics. Application of the proposed approach to two illustrative example water distribution networks demonstrates its capability of adaptively discovering contaminant source characteristics as well as evaluating the degree of non-uniqueness of solutions. The results also showed that the local search as an optimizer has better performance than a standard evolutionary algorithm (EA). [Copyright &y& Elsevier]

Abstract: The volume of industrial and domestic wastewater is increasing significantly year by year with the change in the lifestyle based on mass consumption and mass disposal brought about by the dramatic development of economies and industries. Therefore, effective advanced wastewater treatment is required because wastewater contains a variety of constituents such as particles, organic materials, and emulsion depending on the resource. However, residual chemicals that remain during the treatment of wastewaters form a variety of known and unknown by-products through reactions between the chemicals and some pollutants. Chronic exposure to these by-products or residual chemicals through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. For example, residual aluminium salts in treated water may cause Alzheimer''s disease (AD). As for carbon nanotubes (CNTs), despite their potential impacts on human health and the environment having been receiving more and more attention in the recent past, existing information on the toxicity of CNTs in drinking water is limited with many open questions. Furthermore, though general topics on the human health impacts of traditional water treatment chemicals have been studied, no comparative analysis has been done. Therefore, a qualitative comparison of the human health effects of both residual CNTs and traditional water treatment chemicals is given in this paper. In addition, it is also important to cover and compare the human health effects of CNTs to those of traditional water treatment chemicals together in one review because they are both used for water treatment and purification. [Copyright &y& Elsevier]

Abstract: Aim: This paper describes the spatio-temporal variation of trihalomethanes in drinking water in New South Wales, Australia from 1997 to 2007 Method: We obtained data on trihalomethanes (THMs) from two metropolitan and 13 rural water utilities and conducted a descriptive analysis of the spatial and temporal trends in THMs and the influence of season and drought. Results: Concetrations of monthly THMs in the two metropolitan water utilities of Sydney/Illawarra (mean 66.8 μg/L) and Hunter (mean 62.7 μg/L) were similar compared to the considerable variation between rural water utilities (range in mean THMs: 14.5–330.7 μg/L). Chloroform was the predominate THM in two-thirds of the rural water utilities. Higher concentrations of THMs were found in chlorinated water distribution systems compared to chloraminated systems, and in distribution systems sourced from surface water compared to ground water or mixed surface and ground water. Ground water sourced supplies had a greater proportion of brominated THMs than surface water sourced supplies. There was substantial variation in concentration of THMs between seasons and between periods of drought or no drought. There was a moderate correlation between heavy rainfall and elevated concentrations of THMs. Conclusion: There is considerable spatial and temporal variation in THMs amongst New South Wales water utilities and these variations are likely related to water source, treatment processes, catchments, drought and seasonal factors. [Copyright &y& Elsevier]

Abstract: In a nuclear accident eventuality, the decontamination of potable water without disturbing the water quality is one of the major challenges. During this work, efforts have been made to reduce the contamination of americium (Am)-241 from potable water effectively by using calcium alginate followed by treatment with activated charcoal. Laboratory simulated experiments were carried out for the removal of low level of Am-241 from the potable water originated from groundwater, rain water and lake water. Water samples after filtering through 0.45μm filter paper were spiked in the range of 10–200Bq L−1 of Am-241 as Am(NO3)3. In the pH range 1–8, 60–98% Am was sorbed in the beads with a maximum observed at pH 4±0.2. It was observed that the variation of carbonate, bicarbonate, does not influence the sorption capacity of calcium alginate whereas the DOC decreased the sorption capacity in the range of 40–93% depending on DOC concentration. Ninety-eight to ninety-nine percent of Am is recovered from sodium alginate beads by using 0.6M HNO3. The mechanism of interaction of Am with calcium alginate is proposed based on attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). [Copyright &y& Elsevier]

Abstract: Adsorption is one of the important techniques in separation including the use of activated carbon to remove organic micropollutants from water in treating of drinking water production. Although the adsorption processes to remove contaminant from water have been used widely, the models to describe in detail the adsorption mechanisms need to be formulated. This paper uses the relation [k L a] f =[k L a] g e −βq to develop the mathematical models to determine the resistance of mass transfer. Parameters in equations are all physically meaningful, experimental data validation shows that the equations remained accurate. The global, external, and internal mass transfer factors are analyzed to contribute to adsorption mechanism investigation. The resistances of mass transfer for adsorption of the different surfactants onto granular activated carbons are verified. [Copyright &y& Elsevier]

Abstract: Fluoride content in groundwater that is greater than the WHO limit of 1.5mg/L, causes dental and skeletal fluorosis. In India, several states are affected with excess fluoride in groundwater. The problem is aggravated due to the lack of appropriate and user friendly defluoridation technology. Several fluoride removal techniques are reported in the literature amongst which the Nalgonda technique and use of activated alumina have been studied extensively. However a simple, efficient and cost effective technology is not available for widespread use in many affected regions. In this paper, we present a novel cost effective defluoridation method that is based on surface modification of rice husk ash (RHA) by coating aluminum hydroxide. RHA is obtained by burning rice/paddy husk which is an abundantly available and is an inexpensive raw material. The results showed excellent fluoride removal efficiency and the adsorption capacity was found to be between 9 and 10mg/g. [ABSTRACT FROM AUTHOR]

Abstract: Endemic occurrence of chronic kidney disease with unknown etiology is reported in certain parts of the north central dry zone of Sri Lanka and has become a new and emerging health issue. The disease exclusively occurs in settlements where groundwater is the main source of drinking water and is more common among low socio-economic groups, particularly among the farming community. Due to its remarkable geographic distribution and histopathological evidence, the disease is believed to be an environmentally induced problem. This paper describes a detailed hydrogeochemical study that has been carried out covering endemic and non-endemic regions. Higher fluoride levels are common in drinking water from both affected and non-affected regions, whereas Ca-bicarbonate type water is more common in the affected regions. In terms of the geochemical composition of drinking water, affected households were rather similar to control regions, but there is a large variation in the Na/Ca ratio within each of the two groups. Fluoride as shown in this study causes renal tubular damage. However it does not act alone and in certain instances it is even cytoprotective. The fine dividing line between cytotoxicity and cytoprotectivity of fluoride appears to be the effect of Ca2+ and Na+ of the ingested water on the F− metabolism. This study illustrates a third major cause (the other two being hypertension and diabetes) of chronic kidney diseases notably in tropical arid regions such as the dry zone of Sri Lanka. [ABSTRACT FROM AUTHOR]

Abstract: Many countries have to monitor and control the radioactivity in drinking waters in order to ensure compliance with the requirements of their respective regulations. Among radionuclides responsible for this radioactivity there are 210Po and 210Pb, which are usually not in radioactive equilibrium in waters. This paper deals with the analysis of this disequilibrium and the way that the water treatment plants affect it. To do this, 210Po and 210Pb activity concentrations were measured in raw and drinking water. The measurements were performed by alpha-particle spectrometry and gas flow proportional counting and the corresponding formulae for uncertainties and detection limits are presented. The values obtained show that the Po/Pb ratio is lower in surface than in ground waters. Regarding water treatment, this ratio adopts values lower in drinking water than in raw waters. In any case, for the waters analysed in this work the committed effective doses due to these radionuclides, are negligible. [Copyright &y& Elsevier]

Abstract: Contamination of drinking water by arsenic is a serious public health issue in many parts of the world. One recent approach to this problem has been to filter out arsenic by use of granular ferric hydroxide (GFH), an adsorbent developed specifically for the selective removal of arsenic from water. Previous studies have documented the efficiency and high treatment capacity of this approach. We present a novel X-ray fluorescence method to monitor the accumulation of arsenic within a specially designed GFH column, as both a function of time (or water volume) and location along the column. Using a miniature X-ray tube and silicon PiN diode detector, X-ray fluorescence is used to detect characteristic X-rays of arsenic excited from within the GFH. Trials were performed using a water flow rate of approximately 1.5L per hour, with an added arsenic concentration of approximately 1000μg per litre. In this paper, trial results are presented and potential applications described. [Copyright &y& Elsevier]

Abstract: A bibliometric analysis based on Science Citation Index (SCI) published by Institute of Scientific Information (ISI) was carried out to identify the global research related to lead in drinking water field from 1991 to 2007 and to improve the understanding of research trends in the same period. The results from this analysis indicate that there have been an increasing number of annual publications mainly during two periods: from 1992 to 1997 and from 2004 to 2007. United States produced 37% of all pertinent articles followed by India with 8.0% and Canada with 4.8%. Science of the Total Environment published the most articles followed by Journal American Water Works Association and Toxicology. Summary of the most frequently used keywords are also provided. “Cadmium” was the most popular author keyword in the 17years. Furthermore based on bibliometric results four research aspects were summarized in this paper and the historical research review was also presented. [Copyright &y& Elsevier]

Abstract: Carbon nanotube (CNT) adsorption technology has the potential to support point of use (POU) based treatment approach for removal of bacterial pathogens, natural organic matter (NOM), and cyanobacterial toxins from water systems. Unlike many microporous adsorbents, CNTs possess fibrous shape with high aspect ratio, large accessible external surface area, and well developed mesopores, all contribute to the superior removal capacities of these macromolecular biomolecules and microorganisms. This article provides a comprehensive review on application of CNTs as adsorbent media to concentrate and remove pathogens, NOM, and cyanobacterial (microcystin derivatives) toxins from water systems. The paper also surveys on consideration of CNT based adsorption filters for removal of these contaminants from cost, operational and safety standpoint. Based on the studied literature it appears that POU based CNT technology looks promising, that can possibly avoid difficulties of treating biological contaminants in conventional water treatment plants, and thereby remove the burden of maintaining the biostability of treated water in the distribution systems. [Copyright &y& Elsevier]

Abstract: Disinfection by-products (DBPs) have caused a great threat to drinking water security. Nitrosoamines that are potent carcinogenic, mutagenic, and teratogenic have been discovered in disinfection process as a new kind of DBPs. Accordingly, nitrosoamines elimination from water should be of particular concern. In this paper, UV irradiation was used to degrade the model DBPs: N-nitrosopyrrolidine (NPyr) and N-nitrosopiperidine (NPip). The results showed that UV irradiation was an effective method for the removal of both NPyr and NPip from water. NPip was easier to be degraded compared with NPyr. Water pH had little effect on NPyr photodegradation, but had great influence on NPip photodegradation. The characteristic of the natural water influenced the removal efficiency of NPyr and NPip slightly, suggesting that UV irradiation was effectual to eliminate NPyr and NPip in practice. Due to N–N bond fission, pyrrolidine and piperidine were generated as the primary products of NPyr and NPip photodegradation, respectively. Then aliphatic amines with low molecular weight were formed as further degradation products of NPyr, including methylamine, dimethylamine, ethylamine, diethylamine, n-propylamine and n-methylethylamine. Methylamine, dimethylamine, n-propylamine, n-methylethylamine, diethylamine, n-butylamine and n-amylamine were formed as the further degradation products of NPip. [Copyright &y& Elsevier]

Abstract: This paper specifically discusses a water quality modeling and health risk assessment for cesium-137 to assess the potential and actual effects on human health from drinking water contaminated by a radiological terrorist attack in the Seoul metropolitan area, Korea. With respect to the source term caused by a terrorist attack, it was assumed that 50TBq of cesium-137 was introduced into the Paldang Lake which is a single water resource for the Seoul metropolitan area. EFDC (Environmental Fluid Dynamics Code) model was used to calculate the hydrodynamic and water quality for the model domain, Paldang Lake. Mortality risk and morbid risk coefficients caused by the ingestion of tap water were used to assess a human health risk due to cesium-137. The transport of cesium-137 in the Paldang water system was mainly dependent on the flow streamlines and the effect of the dilution from the other branches. The mortality and morbidity risks due to the drinking water contamination by cesium-137 were 4.77×10−7 and 6.92×10−7, respectively. Accordingly, it is very important to take appropriate countermeasures when radiological terrorist attacks have occurred at water resources to prevent radiological risks by radionuclides. [Copyright &y& Elsevier]

Abstract: The present paper presents results of the study in removal of iron, arsenic and total coliform from drinking water using single-pass constructed soil filter (CSF). Results indicated that arsenic levels ranged from 0.5 to less than 10μgl−1 levels; iron from 5 to less than 0.3mgl−1 and coliform from 10−5 to less than 5CFU/100ml. The results revealed very high removal efficiency, i.e., over 99% and water quality as per WHO standard. [Copyright &y& Elsevier]

Besides trihalomethanes (THMs) and haloacetic acids (HAAs), chloral hydrate (CH) is the next most prevalent disinfection by-product (DBP) in drinking water, formed as a result of the reaction between chlorine and natural organic matter (NOM). Chloral hydrate (trichloroacetaldehyde) should be limited in drinking water because of its adverse health effect. The controversies concerning the appearance of CH in disinfected water found in literature are discussed in the present paper. According to some authors the CH yield during chlorination of water depends only on TOC. However, there are other data available that do not confirm this relationship. Another fact requiring clarification is the dependence of CH formation on pH. In the present study, CH formation is analysed in different types of water disinfected with different doses of chlorine. Formation of CH is correlated with the dose of Cl2 and the contact time. The formation of chloral hydrate takes place as long as chlorine is available in the water. Total organic carbon (TOC) is not considered the main factor influencing the production of chloral hydrate in water treated with Cl2 as the production depends also on the nature of NOM. Higher levels of CH are observed at alkaline conditions (pH>7). A significant correlation (R 2 >0.9) between the concentrations of chloral hydrate and chloroform has been observed. The preozonation increases significantly the chloral hydrate formation potential in the water treated. Biofiltration process does not remove all of CH precursors and its efficiency depends strongly on the contact time. Chloral hydrate was analyzed by gas chromatography with electron capture detector with the detection limit 0.1μgL−1. [Copyright &y& Elsevier]