Water 2011, 3, 1050-1076; doi:10.3390/w3041050 OPEN ACCESS
water ISSN 2073-4441 www.mdpi.com/journal/water Article
Arsenic Contamination in Groundwater of Bangladesh: Perspectives on Geochemical, Microbial and Anthropogenic Issues Hossain M. Anawar 1,2,*, Junji Akai 3, Martin Mihaljevič 4, Arif M. Sikder 5, Golam Ahmed 6, Shafi M. Tareq 6 and Mohammad M. Rahman 6 1 2 3
4
5
6
Instituto Tecnológico e Nuclear Reactor, Apartado 21, E.N. 10, Sacavém 2686-953, Portugal Okavango Research Institute, University of Botswana, Private Bag 285, Maun, Botswana Department of Geology, Niigata University, Ikarashi 2, Niigata 950-2181, Japan; E-Mail:
[email protected] Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University in Prague, Albertov 6, Prague 2 128 43, Czech Republic; E-Mail:
[email protected] Center for Environmental Studies (CES), Virginia Commonwealth University (VCU), 1000 W Cary Street, Richmond, VA 23059, USA; E-Mail:
[email protected] Department of Environmental Science, Jahangirnagar University, Dhaka-1342, Bangladesh; E-Mails:
[email protected] (G.A.);
[email protected] (S.M.T.);
[email protected] (M.M.R.)
* Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +351-219946127; Fax: +351-219941039. Received: 14 October 2011 / Accepted: 19 October 2011 / Published: 11 November 2011
Abstract: A groundwater, sediment and soil chemistry and mineralogical study has been performed to investigate the sources and mobilization process of Arsenic (As) in shallow aquifers of Bangladesh. The groundwater from the shallow aquifers is characterized by high concentrations of Arsenic (47.5–216.8 µg/L), iron (0.85–5.83 mg/L), and phosphate, along with high electrical conductivity (EC). The groundwater has both very low oxidation-reduction potential (Eh) and dissolved oxygen (DO) values indicating reducing conditions. By contrast, the deep aquifers and surface waters (pond, canal) have very low concentrations of Arsenic (