Geochemistry of arsenic in the deltaic environment: Shallow versus deeper aquifer levels
Authors: Chatterjee, D., Biswas, A., Majumder, S., Berner, Z. and Neidhardt, H.
Journal: Water-Rock Interaction - Proceedings of the 13th International Conference on Water-Rock Interaction, WRI-13
This study deals with groundwater quality and As mobilization behavior in the shallow (up to -50 m) and deeper (below -100 m) aquifer levels in Bengal Delta Plain. The groundwaters from shallow aquifer levels are enriched with redox sensitive species, HCO 3-, DOC, PO 4-3 and NH 4+, whereas the deeper aquifer level contains relatively low As, PO 4-3, DOCand NH 4+, low to very low Fe (II), and high HCO 3-. In the shallow aquifer levels, As release to the groundwater is a combination of Fe reduction, local recharge and ion-exchange processes. However, in the deeper aquifer As mobilization is mostly governed by carbonate dissolution and chloride exchange processes. © 2010 Taylor & Francis Group, London.