Arsenic mobilization in aquifers of the southwest Songnen basin, P.R. China: evidences from chemical and isotopic characteristics.

摘要: Abstract High As groundwater has widely been found in the inland basins of China. Little is known about distribution and mobilization mechanisms high Songnen basin, where major source for drinking irrigation. Eighty-seven samples, three surface water samples sixty-three sediment were taken from southwest order to investigate spatial constrains As. Results showed that was generally Na–Mg/Ca–HCO 3 type, which had relatively low Eh values neutral-weakly alkaline pH. characterized by concentrations NO − SO 4 2 − , Fe, Mn, H 2 S. Around 65.5% sampled shallow 96% deep greater than 10 μg/L. Sediments higher total contents Fe/Mn oxide-bound area area. Distribution dependent upon hydrogeologic settings, redox potential, microbial degradation organic carbon, precipitation pyrite, siderite, calcite. Along flow path, concentration an increasing trend. mainly distributed low-lying areas. Reducing conditions causes aquifers, led more released sediments with 13 C DOC DIC dissimilatory Fe(III) reduction coupled dissolved carbon would be related aquifers. Although both Fe during these processes, siderite calcite sink As, resulted weak correlation between