US-Bangladesh Cooperative Research: Geochemistry, Petrology, and Microbiology of As-Contaminated Alluvial Sediments and Groundwater, Bangladesh

Auburn University, Auburn AL

Investigators

Abstract

0352936 Uddin Description: This project supports a collaborative project between Dr. Ashraf Uddin, Department of Geology, Auburn University, Auburn, Alabama and Dr. Kazi M. Ahmed, Department of Geology at the University of Dhaka, Dhaka, Bangladesh. They plan to study arsenic-contaminated alluvial sediments and groundwater in Bangladesh. Natural arsenic contamination of shallow groundwater poses a major human health threat in many parts of the world. Recent research indicates that young (Holocene) river floodplain aquifers are most problematic due to their locally high arsenic levels and because they are exploited for drinking by millions of people in developing nations. There is a theory that As is released by reductive dissolution of the As-bearing hydrous ferric oxides (HFO) in the floodplain aquifers. This As-HFO hypothesis may be part of an arsenic geo-, bio-, hydro- (GBH) cycle. Recent research by the PIs has generated field microbiologic data for the As-groundwater cycling processes and has identified genera of FeRB and SRB involved using culturing and molecular biology (16S rDNA) technique from field sites in the USA very similar to affected areas of Bangladesh, India and Vietnam. The condition that lead to this water chemistry in river floodplains is universal, but only rises to a serious problem in the developing nations where this water is exploited for human consumption. The PIs plan to extend and test the conclusions drawn from field areas in USA to a seriously As-affected region of the world, to seek verification of the hypothesis about the universality of biogeochemical controls on this type of natural arsenic contamination. Past research by the PIs has also demonstrated an important role that SRB play in nature in removing As from groundwater. They will test bioremediation process to remove dissolved metal (including As) contaminants in field experiments in Bangladeshi ground waters. The research team has the needed skills and backgrounds to document the cause of the arsenic problem, as well as a potential remediation tool. Scope: The proposed research includes educational and research activities for graduate students and post-docs. The proposed research has significant technology transfer elements in it, during the progress of the study, the PIs will be cooperating with local scientists and government officials, and in the process, will provide the opportunity to educate them how to implement the bioremediation process in the field should this proof-of-concept research prove successful. Because As-contamination is a pressing problem in the developing world, lessons learned in Bangladesh should be applicable to many other countries.