Arsenic in groundwater and sediment in the Mekong River delta, Vietnam.
A study of groundwater and sediment during 2007-2008 in the Mekong River delta in Vietnam (MDVN) revealed that 26%, 74%, and 50% of groundwater samples were above the US EPA drinking water guidelines for As (10 microg/L), Mn (0.05 mg/L), and Fe (0.3 mg/L). The range of As, Fe, and Mn concentrations in the MDVN were <0.1-1351 microg/L, <0.01-38 mg/L, and <0.01-14 mg/L, respectively. Elevated levels of As were found in groundwater at sampling sites close to the Mekong River and in wells less than 60-70 m deep. An inverse relationship was found between As and Mn concentrations in groundwater. Sediment samples from An Giang and Dong Thap had the highest As concentrations (18 mg/kg and 38 mg/kg, respectively). Arsenic sediment occurred mainly in the poorly crystalline Fe oxide phases. Reductive dissolution of the Fe oxide phase is not necessarily the dominant mechanism of As release to groundwater.
Hoang
Thi Hanh
TH
Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Republic of Korea.
Bang
Sunbaek
S
Kim
Kyoung-Woong
KW
Nguyen
My Hoa
MH
Dang
Duy Minh
DM
D001151:Arsenic / Q000032:analysis*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D014744:Vietnam; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis
D014874:Water Pollutants, Chemical; D001151:Arsenic