scholarly journals Characteristics on distribution of chemical composition in groundwater along the Mekong and Bassac (Hậu) river, Vietnam

2019 ◽  
Vol 41 (3) ◽  
Author(s):  
Hikaru Sat Hikaru Sato ◽  
Naoaki Shibasaki ◽  
Huynh Mai Ly ◽  
Nguyen Van Lap ◽  
Ta Thi Kim Oanh

Along the Mekong River (MR), arsenic contamination in the groundwater has been recognized since the 2000s. Due to arsenic contamination in shallow aquifers, the drinking water has been prevented from being contaminated with arsenic by installing wells, 200 m to 400 m deep. However, it has been known that groundwater was contaminated by not only arsenic but also other trace elements. The need to reveal characteristics on the distribution of chemical composition by horizontally and vertically is increasing for purposes of appropriate development and management of groundwater. This study summarized the results of surveys for arsenic since 2008 and surveys for dissolved ions and trace elements since 2015, and described characteristics on distribution for chemical composition at the regional areas along the MR and Bassac (Hậu) River (BR). Groundwater samples were collected from existing wells in 8 provinces and 1 city. The authors used Piper and Stiff diagram that reflect the chemical composition of groundwater to respond to varying horizontal and vertical distributions. The Principal Component Analysis (PCA) was also carried out to reveal the correspondences of dissolved ions and trace elements. Variety concentrations and distributions of ions and trace elements show the obvious distinction between upper (<200 m deep) and lower (>200 m deep) aquifers broadly divided by geologic age. A wide variety of ion compositions and trace elements was found in the upper aquifer, and concentration of some trace elements in groundwater was high and exceed the World Health Organization (WHO) drinking water guideline value. On the other hand, groundwater in the lower aquifer is simple and rarely contaminated by trace elements. However, the arsenic concentration ranging from 0.01–0.065 mg/L slightly exceeding the WHO guideline value was found at the lower aquifer in the downstream areas of the Mekong River Delta. These results on the distribution analysis provide the insight that deep groundwater is not necessarily safe by over-pumping from deep aquifer and drilling new wells in the downstream areas.

2013 ◽  
Vol 1 ◽  
pp. 57-62
Author(s):  
Suman Man Shrestha ◽  
S. P. Wagley ◽  
S. Parajuli ◽  
U. KC ◽  
A. KC

A study was conducted at 13 different areas of Kathmandu Valley to know the status of arsenic in deep tube wells in post monsoon and winter in 2009 and 2010. The depth of the deep tube wells ranged from 75 m to 304 m. The study was also carried out to know the correlations between depths of the deep tube wells and arsenic concentration. The collected samples were analyzed as per standard method using spectrophotometer. The correlations of arsenic concentration in different season (post monsoon and winter) were also studied. 92.31% of deep tube wells in post monsoon and winter exceeded permissible values of World Health Organization guideline value 0.01 mg/L for drinking water but 38.46% deep tube wells in post monsoon and 46.15% of deep tube wells in winter exceeded permissible values of Nepal Drinking Water Standard of 0.05 mg/L. There was strong positive correlation in arsenic concentration between post monsoon and winter(r=0.94, p<0.001). There was weak but positive correlation between arsenic concentration and depth of deep tube wells in winter ( r=0.23, p=0.451). There was very weak correlations between arsenic concentration and depth of deep tube wells in post monsoon (r=0.055, p=0.859). The trend distribution maps were generated for arsenic in post monsoon and winter.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Juan D. Paoloni ◽  
Mario E. Sequeira ◽  
Martín E. Espósito ◽  
Carmen E. Fiorentino ◽  
María del C. Blanco

Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahía Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the WHO (Guidelines for Drinking Water Quality, 2004). and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water.


1999 ◽  
Vol 34 (2) ◽  
pp. 305-316 ◽  
Author(s):  
E.H. Bakraji ◽  
J. Karajo

Abstract Total reflection X-ray fluorescence spectrometry and chemical preconcentration have been applied for multi-elemental analysis of Damascus drinking water. Water was taken directly from taps of several city sectors and analyzed for the following trace elements: Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Se and Pb. The detection limits were found to be in the range of 0.1 to 0.4 µg/L. The mean levels of trace elements in the Damascus drinking water were below the World Health Organization drinking water quality guidelines.


2006 ◽  
Vol 5 (1) ◽  
pp. 171-178 ◽  
Author(s):  
Tim Wrigley

Low technology water supply, treatment and sanitation techniques were reviewed in a Vietnamese village in the Mekong River Delta as part of an AusAID Project to reduce poverty and to improve the overall living standards and health in the Cuu Long (Mekong) delta for 500,000 rural poor. It was found that dosing of canal water in 200-l ceramic jars with alum, PAC or PAC followed by hypochlorite provides a high level of treatment for drinking water at the household level in a rural village setting in the Mekong River delta. Seventy per cent (7 in total) of the 24 samples collected showed that Escherichia coli levels per 100 ml in the jars after treatment showed a ‘no risk’ profile (0 E. coli 100 ml-1) i.e. the water would be considered to be of very good quality for drinking according to World Health Organization Guidelines for Rural Drinking Water Supply. This included the eight samples that were dosed with hypochlorite. The remaining 30% of samples (seven in total) ranged from 14 to 47 E. coli 100 ml-1 which is considered an intermediate risk (10‒100 E. coli 100 ml-1) according to WHO guidelines. All control water samples (eight in total) were high or very high risk (&gt;100 E. coli 100 ml-1). Pesticide concentrations generally were low and met Vietnamese drinking water quality criteria.


Inner Asia ◽  
2014 ◽  
Vol 16 (2) ◽  
pp. 427-441 ◽  
Author(s):  
Osamu Nagafuchi ◽  
Koyomi Nakazawa ◽  
Kanji Okano ◽  
Ken’ichi Osaka ◽  
Yuki Nishida ◽  
...  

Increasing large-scale and rampant small-scale mining activity in Mongolia is raising fears about the possibility of regional environmental pollution. To characterise the level of groundwater pollution related to large- and small-scale underground resource development in the Mongolian plateau, we analysed 10 groundwater and 3 surface water samples collected from three areas: the Oyu Tolgoi mining area (n = 3), the Tavan Tolgoi mining area (n = 9) and an abandoned small-scale gold-mining site in the suburban of Ulaanbaatar (n = 1). The samples were collected between 29 August and 5 September 2012. Measurement parameters included pH; electrical conductivity; dissolved organic carbon; dissolved nitrogen; and the concentrations of major ions and trace elements. Principal component analyses, Piper diagrams and enrichment factor analyses were applied to a set of hydrochemical data. Water samples were analysed to identify components that may adversely affect the regional environment and human health. Analytical measurements showed that the studied sites were highly affected by fossil salt water and trace elements derived from anthropogenic activity. We found that groundwater samples from the Oyu Tolgoi area were more polluted than those from the Tavan Tolgoi area. Because wells in the pasture area adjacent to the mining sites supply drinking water for livestock and nomads, it is especially important to monitor these wells for NO3−, As and Se, for which the World Health Organisation has established drinking-water guidelines. The concentrations of NO3−, As and Se in wells may be used as indicators to evaluate the human and livestock health risks related to mining activity in this area.


2021 ◽  
Vol 13 (1) ◽  
pp. 146-152
Author(s):  
Rishabh Tiwari ◽  
Satwik Satwik ◽  
Prateek Khare ◽  
Satyam Rai

Herein the present study focuses on arsenic (As) contamination in groundwater, which plagues a vast section of the population of the world. Even the conservative estimates by the World Health Organization (WHO) estimate the number of people plagued by arsenic contaminated drinking water to be around 140-200 million. The Ganga- Brahmaputra fluvial plains in India and Padma-Meghna fluvial plains in Bangladesh are said to be one of the worst groundwater calamities to the humans. The Arsenic levels in drinking water in some of the most populated states in India are disproportionately higher than those defined by WHO guidelines. The paper, thus, delves into the anomaly in permissible limits defined by WHO and regional governments and its consequential effects. It briefly analyses the major sources of Arsenic contamination and its health effects in India. The study also looks closely into the states and districts plagued by the As contamination and explores the prominent treatment methods employed in as removal from the drinking water. Keywords: Arsenic, Adsorption, Geogenic, Arsenopyrite, Oxidation treatment


2021 ◽  
Author(s):  
Nevetha Yogarajah ◽  
Scott S. H. Tsai

Arsenic contamination of drinking water is a major global problem, with contamination in Bangladesh deemed most serious. Although the current World Health Organisation (WHO) maximum contamination limit (MCL) for arsenic in drinking water is 10 μg L−1, due to practical and economic constraints, the standard limit in Bangladesh and many other developing nations is 50 μg L−1. We propose that an ideal arsenic sensor, designed for routine monitoring, will have five essential qualities: sensitivity and selectivity for arsenic; speed and reliability; portability and robustness; reduced health and environmental risks; and affordability and ease of use for local technicians. It is our opinion that many of these characteristics can be accentuated by microfluidic systems. We describe candidate colorimetric, electrochemical, biological, electrophoretic, surface-sensing, and spectroscopic methods for arsenic detection; and comment on their potential for portable microfluidic adaptation. We also describe existing developments in the literature towards the ultimate creation of microfluidic total analysis systems (μTASs) for arsenic detection. The fundamental purpose of this review is to highlight the need for better portable arsenic contamination detection, and describe how microfluidic technology may be developed to address this need.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3510
Author(s):  
Ana Moldovan ◽  
Maria-Alexandra Hoaghia ◽  
Eniko Kovacs ◽  
Ionuț Cornel Mirea ◽  
Marius Kenesz ◽  
...  

In rural areas without centralized water supply systems, inhabitants often use groundwater of unknown quality as drinking water, without understanding the possible negative consequences on their health. Karstic spring waters from Dobrogea region in Romania were assessed for their potential to be used as drinking water source, according to their quality and seasonal variation. The physico-chemical parameters of waters were compared with the guideline values for drinking water established by the World Health Organization and the Directive 98/83/EC. The nitrate and Cr concentrations exceeded the guideline value in the springs from Southern Dobrogea, but met the quality criteria in those from Northern Dobrogea, thus, to be used as drinking water, the karstic springs located in Southern Dobrogea require treatment for nitrates removal. Heavy metals pollution indices showed low to medium cumulative heavy metal pollution in all springs, while the human health risk assessment by oral exposure indicated possible noncarcinogenic risks of nitrates, both for adults and children in springs from South Dobrogea. A rigorous monitoring of the water quality before human consumption is recommended for all four studied water sources.


2018 ◽  
Vol 15 (3) ◽  
pp. 270-277
Author(s):  
Baghdad Science Journal

The toxicological risks and lifetime cancer risks associated with exposure to disinfection by-products (DBPs) including Halloacetic acids (HAAs) and trihalomethanes (THMs) compounds by drinking water in several districts in Wassit Province were estimated. The seasonal variation of HAAs and THMs compounds in drinking water have indicated that the mean values for total HAAs (THAAs) and total THMs (TTHMs) ranged from 43.2 to 72.4 mg/l and from 40 to 115.5 mg/l, respectively. The World health organization index for additive toxicity approach was non-compliant with the WHO guideline value in summer and autumn seasons and this means that THMs concentration has adverse toxic health effects. The multi-pathway of lifetime human health risk of cancer credited to THMs and HAAs in drinking water via three exposure routes for THMs and only one exposure route for HAAs was evaluated and found to be 6.13×10-4 and 1.78×10-4 respectively and these values were higher than the US.EPA range of concern limit of 1×10-6. The risk ratio of THAAs to TTHMs was 3.44. Also, the highest cancer risk was recorded for BDCM followed by DBCM, CF, TCAA, DCAA, and BF.


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