Tag Archives: drinking water quality

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.

Tap Water Quality within a New Residential Green Building

Salehi M, Abouali M, Wang M, Zhou Z, Nejadhashemi AP, Mitchell J, Caskey S, Whelton AJ. Case study: Fixture water use and drinking water quality in a new residential green building. Chemosphere. 2017 Nov 30;195:80-89. doi: 10.1016/j.chemosphere.2017.11.070.

Residential plumbing is critical for the health and safety of populations worldwide. A case study was conducted to understand fixture water use, drinking water quality and their possible link, in a newly plumbed residential green building. Water use and water quality were monitored at four in-building locations from September 2015 through December 2015. Once the home was fully inhabited average water stagnation periods were shortest at the 2nd floor hot fixture (90 percentile of 0.6-1.2 h). The maximum water stagnation time was 72.0 h. Bacteria and organic carbon levels increased inside the plumbing system compared to the municipal tap water entering the building. A greater amount of bacteria was detected in hot water samples (6-74,002 gene copy number/mL) compared to cold water (2-597 gene copy number/mL). This suggested that hot water plumbing promoted greater microbial growth. The basement fixture brass needle valve may have caused maximum Zn (5.9 mg/L), Fe (4.1 mg/L), and Pb (23 μg/L) levels compared to other fixture water samples (Zn ≤ 2.1 mg/L, Fe ≤ 0.5 mg/L and Pb ≤ 8 μg/L). At the basement fixture, where the least amount of water use events occurred (cold: 60-105, hot: 21-69 event/month) compared to the other fixtures in the building (cold: 145-856, hot: 326-2230 event/month), greater organic carbon, bacteria, and heavy metal levels were detected. Different fixture use patterns resulted in disparate water quality within a single-family home. The greatest drinking water quality changes were detected at the least frequently used fixture.

Drinking Water Quality in Rural Oaxaca, Mexico

Rowles LS 3rd, Alcalde R, Bogolasky F, Kum S, Diaz-Arriaga FA, Ayres C, Mikelonis AM, Toledo-Flores LJ, Alonso-Gutiérrez MG, Pérez-Flores ME, Lawler DF, Ward PM, Lopez-Cruz JY, Saleh NB. Perceived versus actual water quality: Community studies in rural Oaxaca, Mexico. Sci Total Environ. 2017 Dec 6;622-623:626-634. doi: 10.1016/j.scitotenv.2017.11.309.

Compromised water quality risks public health, which becomes particularly acute in economically marginalized communities. Although the majority of the clean-water-deprived population resides in Sub-Saharan Africa and Asia, a significant portion (32 million) lives in Meso- and Latin-America. Oaxaca is one of the marginalized southern states of Mexico, which has experienced high morbidity from infectious diseases and also has suffered from a high rate of infant mortality. However, there has been a paucity of reports on the status of water quality of culturally diverse rural Oaxaca. This study follows community-based participatory research methods to address the data gap by reporting on water quality (chemical and microbiological) and by exploring social realities and water use practices within and among communities. Surveys and water quality analyses were conducted on 73 households in three rural communities, which were selected based on the choice of water sources (i.e., river water, groundwater, and spring water). Statistically significant variations among communities were observed including the sanitation infrastructure (p-value 0.001), public perception on water quality (p-value 0.007), and actual microbiological quality of water (p-value 0.001). Results indicate a high prevalence of diarrheal diseases, a desire to improve water quality and reduce the cost of water, and a need for education on water quality and health in all the surveyed communities. The complexities among the three studied communities highlight the need for undertaking appropriate policies and water treatment solutions.

Is Trace Lithium in Tap Water Beneficial?

Small associations from ecological studies are questionable whether the effect is negative or as in this case positive.

Fajardo VA, LeBlanc PJ, Fajardo VA. Trace lithium in Texas tap water is negatively associated with all-cause mortality and premature death. Applied physiology, nutrition, and metabolism 2017 Dec 5. doi: 10.1139/apnm-2017-0653.

Lithium in tap water was previously found to have life-extending effects across 18 Japanese municipalities. Using a larger dataset with several Texas counties, our study shows that lithium concentrations in tap water are negatively associated with all-cause mortality (r = -0.18, p = 0.006, 232 counties) and years of potential life lost (r = -0.22, p = 0.001, 214 counties). Thus, our present findings extend and reinforce lithium’s purported life-prolonging effect in humans.