Arsenic-enriched groundwaters of India, Bangladesh and Taiwan-Comparison of hydrochemical characteristics and mobility constraints
2011 (English)In: Journal of Environmental Science and Health. Part A: Toxic/Hazardous Substances and Environmental Engineering, ISSN 1093-4529, E-ISSN 1532-4117, Vol. 46, no 11, 1163-1176 p.Article in journal (Refereed) Published
Arsenic (As) enrichment in groundwater has become a major global environmental disaster. Groundwater samples were collected from 64 sites located in the districts of 24-Parganas (S), and Nadia in West Bengal, India (Bhagirathi sub-basin), and 51 sites located in the districts of Comilla, Noakhali, Magura, Brahman baria, Laxmipur, Munshiganj, Faridpur and Jhenaida in Bangladesh (Padma-Meghna sub-basin). Groundwater samples were also collected from two As-affected areas (Chianan and Lanyang plains) of Taiwan (n = 26). The concentrations of major solutes in groundwater of the Padma-Meghna sub-basin are more variable than the Bhagirathi sub-basin, suggesting variations in the depositional and hydrological settings. Arsenic concentrations in groundwaters of the studied areas showed large variations, with mean As concentrations of 125 mu g/L (range: 0.20 to 1,301 mu g/L) in Bhagirathi sub-basin, 145 mu g/L (range: 0.20 to 891 mu g/L) in Padma-Meghna sub-basin, 209 mu g/L (range: 1.3 to 575 mu g/L) in Chianan plain, and 102 mu g/L (range: 2.5 to 348 mu g/L) in Lanyang plain groundwater. The concentrations of Fe, and Mn are also highly variable, and are mostly above the WHO-recommended guideline values and local (Indian and Bangladeshi) drinking water standard. Piper plot shows that groundwaters of both Bhagirathi and Padma-Meghna sub-basins are of Ca-HCO(3) type. The Chianan plain groundwaters are of Na-Cl type, suggesting seawater intrusion, whereas Lanyang plain groundwaters are mostly of Na-HCO(3) type. The study shows that reductive dissolution of Fe(III)-oxyhydroxides is the dominant geochemical process releasing As from sediment to groundwater in all studied areas.
Place, publisher, year, edition, pages
2011. Vol. 46, no 11, 1163-1176 p.
Arsenic, Bengal Basin, Chianan plain, Fe-reduction, geochemistry, trace elements
IdentifiersURN: urn:nbn:se:kth:diva-46871DOI: 10.1080/10934529.2012.598711ISI: 000295716900002ScopusID: 2-s2.0-80052486966OAI: oai:DiVA.org:kth-46871DiVA: diva2:454291
QC 201111072011-11-072011-11-072012-02-13Bibliographically approved