Preliminary Evaluation of the Nature, Extent, and Treatment of Arsenic-Affected Drinking Water in Bangladesh

Seth H. Frisbie, Ph.D., Donald M. Maynard, P.E., and Bilqis A. Hoque, Ph.D.

1. Abstract

     The people of Bangladesh used to rely on surface water for drinking, which was often contaminated with cholera and other life-threatening diseases. To reduce the incidences of these diseases, millions of tubewells were installed in Bangladesh over the last 3 decades. This recent transition from surface water to groundwater has significantly reduced deaths from water-borne pathogens; however, new evidence suggests disease and death from arsenic and potentially other metals in groundwater are impacting large areas of Bangladesh. An estimated 50,000,000 Bangladeshis are currently at risk of disease and death from chronic arsenic poisoning (1 and 2).

     In this preliminary evaluation the areal and vertical distribution of arsenic and other inorganic chemicals in groundwater was mapped throughout Bangladesh. The study suggests that a major source of this arsenic may be one or more phosphate minerals containing arsenate as an impurity. Evidence for other potentially toxic heavy metals in groundwater was also discovered. Several appropriate treatment technologies were evaluated.

• 2. Introduction
• 2.1. Geographic, Demographic, and Economic Overview of Bangladesh
• 2.2. Project Overview
• 3. Materials and Methods
• 3.1. Groundwater Sample Collection, Preservation, Storage, and Analyses
• 3.2. Soil Leaching Study
• 3.3. Bench-Scale Treatability Study for Arsenic Removal from Groundwater
• 4. Results and Discussion
• 4.1. Evaluation of Analytical Chemistry Capability and Evidence that Other Potentially Toxic Metals are Widely Distributed in Groundwater
• 4.2. The Nature and Extent of Arsenic, Chloride, Phosphate, Sulfide, Sulfate, and Total Iron in Groundwater
• 4.3. The Effects of Arsenic and These Other Toxic Metals on Human Health
• 4.4. The Leaching of Arsenic from Surface Soils and its Potential Impact on Food Crops
• 4.5. The Potential of Groundwater Monitoring to Reduce the Need for Arsenic Treatment
• 4.6. The Potential of Drilling Deeper Tubewells to Reduce the Need for Arsenic Treatment
• 4.7. Implications of the Expected Nature of Arsenic in Groundwater on Treatment
• 4.8. The Results of the Bench-Scale Treatability Study for Arsenic Removal from Groundwater
• 4.9. The Conceptual Design of a Pilot-Scale Treatment System for Removing Arsenic and Other Potentially Toxic Metals from Groundwater
• 5. Conclusions and Recommendations
• 6. References
• 7. Acknowledgments
• 8. View Tables
• 9. View Maps and Figures

• Contact Seth H. Frisbie, Ph.D. (shf3@cornell.edu) by e-mail.