Fate of Arsenic during Red River Water Infiltration into Aquifers beneath Hanoi, Vietnam.

ABSTRACT: Recharge of Red River water into arsenic-contaminated aquifers below Hanoi was investigated. The groundwater age at 40 m depth in the aquifer underlying the river was 1.3 ± 0.8 years, determined by tritium-helium dating. This corresponds to a vertical flow rate into the aquifer of 19 m/year. Electrical conductivity and partial pressure of CO₂ (P_CO2) indicate that water recharged from the river is present in both the sandy Holocene and gravelly Pleistocene aquifers and is also abstracted by the pumping station. Infiltrating river water becomes anoxic in the uppermost aquifer due to the oxidation of dissolved organic carbon. Further downward, sedimentary carbon oxidation causes the reduction of As-containing Fe-oxides. Because the release of arsenic by reduct

SUBMITTER: Postma D 

PROVIDER: S-EPMC5290489 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature