ABSTRACT
XRF results for sediment profile below the jute decomposing pond clearly show 3 zones, i) Zone 1 (0-2.6 m), which has As and Fe concentrations less than their background concentrations in Bengal Delta sediments; ii) Zone 2 (2.6-6.1 m), in which the concentrations of the same elements are higher than their respective background values, and
1 INTRODUCTION
Arsenic (As) contamination in groundwater is posing a major threat to drinking water resources worldwide. West Bengal and Bangladesh are the worst affected areas in the world where more than 36 million people are at risk due to drinking of As contaminated water. Many theories were put forward to explain the mechanism of release of As from sediments to groundwater. The most accepted reduction mechanism (Bhattacharya et al., 1997) considers an internal organic matter source (peat layer) responsible for driving a sequence of reactions which mobilizes As. The effect of different surface derived organic compounds [more often represented in form of a composite parameter as dissolved organic carbon (DOC)] on the mobilization of As is not yet sufficiently investigated. The widely used technique for obtaining jute fiber in West Bengal, that implies the retting of the plant in ponds for several weeks, produces significant amounts of DOC. The possible effect of this traditional procedure on the mobilization of As from the sediments immediately below the ponds was not investigated until now. This gap in knowledge forms the motivation for this work.
