The governing geochemical processes responsible for mobilisation of arsenic in sedimentary aquifer of Bengal Delta Plain

摘要

In Bengal Delta Plain (Bangladesh and West Bengal) the high occurrence of arsenic in groundwater has been noticed during groundwater development. Oxidation and reduction model has been suggested to understand the release of arsenic in ground-water. Examination of ground-water quality reveals that the water is anoxic with high dissolved iron (Ⅱ), phosphate, bicarbonate and low nitrate and sulphate. Arsenic is derived as a consequence of desorption and reductive dissolution of Fe oxyhydroxide occurring as coatings on sedimentary grains.