Category Archives: Drinking Water Quality

USGS study confirms the good-quality of US tap waters

Bradley PM, et al. Reconnaissance of Mixed Organic and Inorganic Chemicals in Private and Public Supply Tapwaters at Selected Residential and Workplace Sites in the United States. Environmental science & technology. 2018 Nov 21. doi: 10.1021/acs.est.8b04622

Safe drinking water at the point-of-use (tapwater, TW) is a United States public health priority. Multiple lines of evidence were used to evaluate potential human health concerns of 482 organics and 19 inorganics in TW from 13 (7 public supply, 6 private well self-supply) home and 12 (public supply) workplace locations in 11 states. Only uranium (61.9 μg L-1, private well) exceeded a National Primary Drinking Water Regulation maximum contaminant level (MCL: 30 μg L-1). Lead was detected in 23 samples (MCL goal: zero). Seventy-five organics were detected at least once, with median detections of 5 and 17 compounds in self-supply and public supply samples, respectively (corresponding maxima: 12 and 29). Disinfection byproducts predominated in public supply samples, comprising 21% of all detected and 6 of the 10 most frequently detected. Chemicals designed to be bioactive (26 pesticides, 10 pharmaceuticals) comprised 48% of detected organics. Site-specific cumulative exposure-activity ratios (∑EAR) were calculated for the 36 detected organics with ToxCast data. Because these detections are fractional indicators of a largely uncharacterized contaminant space, ∑EAR in excess of 0.001 and 0.01 in 74 and 26% of public supply samples, respectively, provide an argument for prioritized assessment of cumulative effects to vulnerable populations from trace-level TW exposures.

Contaminants in drinking water stored in plastic cisterns, Brazil

de Oliveira Moura T, Oliveira Santana F, Palmeira Campos V, de Oliveira IB, Medeiros YDP. Inorganic and organic contaminants in drinking water stored in polyethylene cisterns. Food chemistry. 2019 Feb 1;273:45-51. doi: 10.1016/j.foodchem.2018.03.104.

This work evaluated the presence of contaminants in stored rainwater in 36 polyethylene tanks installed in two rural communities of the semiarid of Bahia, Brazil. Carbonyl compounds were analyzed by High Performance Liquid Chromatography (HPLC-UV), BTEX (Benzene, Toluene, Ethylbenzene and Xylenes) by gas chromatoghaphy (GC-FID), and trace elements by inductively coupled plasma optical emission spectrometry (ICP-OES). Seven carbonyl compounds were quantified including acrolein (<3-115 µg L-1), which is considered a potent mutagenic agent, above the potability limit in 75% of the cases. Trace elements such as copper, zinc, barium, aluminum and lead, more frequently found, were also quantified, and lead (<0,56-99 µg L-1) was above the tolerable limit for drinking water of 10 μg L-1 in 73% of the cases. The results show that the stored water in polyethylene cisterns in the Brazilian semiarid region does not present satisfactory conditions for human consumption.

Drinking water quality in Pakistan

Daud MK, Nafees M, Ali S, Rizwan M, Bajwa RA, Shakoor MB, Arshad MU, Chatha SAS, Deeba F, Murad W, Malook I, Zhu SJ. Drinking Water Quality Status and Contamination in Pakistan. Biomed Res Int. 2017;2017:7908183. doi: 10.1155/2017/7908183.

Due to alarming increase in population and rapid industrialization, drinking water quality is being deteriorated day by day in Pakistan. This review sums up the outcomes of various research studies conducted for drinking water quality status of different areas of Pakistan by taking into account the physicochemical properties of drinking water as well as the presence of various pathogenic microorganisms. About 20% of the whole population of Pakistan has access to safe drinking water. The remaining 80% of population is forced to use unsafe drinking water due to the scarcity of safe and healthy drinking water sources. The primary source of contamination is sewerage (fecal) which is extensively discharged into drinking water system supplies. Secondary source of pollution is the disposal of toxic chemicals from industrial effluents, pesticides, and fertilizers from agriculture sources into the water bodies. Anthropogenic activities cause waterborne diseases that constitute about 80% of all diseases and are responsible for 33% of deaths. This review highlights the drinking water quality, contamination sources, sanitation situation, and effects of unsafe drinking water on humans. There is immediate need to take protective measures and treatment technologies to overcome unhygienic condition of drinking water supplies in different areas of Pakistan.

Water quality in the Tibetan Plateau

Qu B, Zhang Y, Kang S, Sillanpää M. Water quality in the Tibetan Plateau: Major ions and trace elements in rivers of the “Water Tower of Asia”. Sci Total Environ. 2018 Aug 25;649:571-581. doi: 10.1016/j.scitotenv.2018.08.316.

As the “Water Tower of Asia”, rivers originating from the Tibetan Plateau provide water resources for more than one billion residents in both its local and surrounding areas. With respect to the essential role that this region plays in terms of water resources in Asia, we provide an overview of the mechanisms governing the water quality, including the major ions and trace elements release, in eleven rivers of the Tibetan Plateau. Overall, the rivers running on the Tibetan Plateau reflect an alkaline aquatic environment, with an average pH of 8.5; and the total dissolved solids (TDS, ~339 mg L-1) are much higher than the global average value. Over 80% of the water ionic budget in the rivers of the plateau is comprised of Ca2+, Mg2+, HCO3- and SO42-. The main mechanisms that control the river water chemistry on the Tibetan Plateau are natural processes and present a visible spatial heterogeneity. For instance, in rivers of the southern Tibetan Plateau, the water quality is mainly controlled by the rock-weathering, while rivers of the central and northern Tibetan Plateau are also largely affected by evaporation-crystallization processes. In general, most of the rivers on the Tibetan Plateau are uncontaminated and still in a pristine condition. However, it should be noted that due to the natural process such as rock-weathering and groundwater leaching, and anthropogenic activities such as urbanization and mining operations, the concentrations of several toxic elements (e.g., As, Cd, Pb, Mn, Hg and Tl) in some of the basins are higher than the China national standard (GB) and the World Health Organization (WHO) guidelines for drinking water. With increasing anthropogenic activities on the plateau and changes in the river basins, it is necessary to conduct the long-term monitoring of the river water chemistry of this climate-sensitive and eco-fragile region.

Analysis of polonium, plutonium, americium and uranium in drinking water

Lemons, B.; Khaing, H.; Ward, A.; Thakur, P. A rapid method for the sequential separation of polonium, plutonium, americium and uranium in drinking water. Applied Radiation and Isotopes June 2018 136:10-17

A new sequential separation method for the determination of polonium and actinides (Pu, Am and U) in drinking water samples has been developed that can be used for emergency response or routine water analyses. For the first time, the application of TEVA chromatography column in the sequential separation of polonium and plutonium has been studied. This method utilizes a rapid Fe+3 co-precipitation step to remove matrix interferences, followed by plutonium oxidation state adjustment to Pu4+ and an incubation period of ~ 1 h at 50–60 °C to allow Po2+ to oxidize to Po4+. The polonium and plutonium were then separated on a TEVA column, while separation of americium from uranium was performed on a TRU column. After separation, polonium was micro-precipitated with copper sulfide (CuS), while actinides were micro co-precipitated using neodymium fluoride (NdF3) for counting by the alpha spectrometry. The method is simple, robust and can be performed quickly with excellent removal of interferences, high chemical recovery and very good alpha peak resolution. The efficiency and reliability of the procedures were tested by using spiked samples. The effect of several transition metals (Cu2+, Pb2+, Fe3+, Fe2+, and Ni2+) on the performance of this method were also assessed to evaluate the potential matrix effects. Studies indicate that presence of up to 25 mg of these cations in the samples had no adverse effect on the recovery or the resolution of polonium alpha peaks.

Nationwide drinking water sampling for exposure assessment, Denmark

Voutchkova DD, Hansen B, Ernstsen V, Kristiansen SM.Nationwide Drinking Water Sampling Campaign for Exposure Assessments in Denmark. International journal of environmental research and public health. 2018 Mar 7;15(3). pii: E467. doi: 10.3390/ijerph15030467.

Nationwide sampling campaign of treated drinking water of groundwater origin was designed and implemented in Denmark in 2013. The main purpose of the sampling was to obtain data on the spatial variation of iodine concentration and speciation in treated drinking water, which was supplied to the majority of the Danish population. This data was to be used in future exposure and epidemiologic studies. The water supply sector (83 companies, owning 144 waterworks throughout Denmark) was involved actively in the planning and implementation process, which reduced significantly the cost and duration of data collection. The dataset resulting from this collaboration covers not only iodine species (I, IO₃, TI), but also major elements and parameters (pH, electrical conductivity, DOC, TC, TN, F, Cl, NO₃, SO₄2-, Ca²⁺, Mg²⁺, K⁺, Na⁺) and a long list of trace elements (n = 66). The water samples represent 144 waterworks abstracting about 45% of the annual Danish groundwater abstraction for drinking water purposes, which supply about 2.5 million Danes (45% of all Danish residents). This technical note presents the design, implementation, and limitations of such a sampling design in detail in order (1) to facilitate the future use of this dataset, (2) to inform future replication studies, or (3) to provide an example for other researchers.

House hold electrocoagulation filtration process produces potable water

Dhadge VL, Medhi CR, Changmai M, Purkait MK. House hold unit for the treatment of fluoride, iron, arsenic and microorganism contaminated drinking water. Chemosphere 2018 Feb 16;199:728-736. doi: 10.1016/j.chemosphere.2018.02.087.

A first of its kind hybrid electrocoagulation-filtration prototype unit was fabricated for the removal of fluoride, iron, arsenic and microorganisms contaminated drinking water. The unit comprised of 3 chambers, chamber A consisting of an inlet for the water to be treated and an outlet for the treated water along with one block of aluminum electrodes. Chamber B consisted of ceramic membrane filtration assembly at the bottom over a metallic support which filters the flocs so produced in chamber A and chamber C consisting of space to collect the treated water. Operating parameters were maintained as current density of 625 A m-2 and an electrode distance of 0.005 m. Contaminated drinking water containing mixture of fluoride (10 mg L-1), iron (25 mg L-1), arsenic (200 μg L-1) and microorganisms (35 CFU ml-1) was used for the experiment. A removal of 98.74%, 95.65%, 93.2% and 100% were obtained for iron, arsenic, fluoride and microorganisms, respectively. The apparatus and method made it possible to efficiently treat contaminated drinking water to produce drinkable water as per WHO specification. By-products obtained from the electrocoagulation bath were analyzed using SEM, EDX and XRD and explained.