Abstract:

The aquifer sediment samples collected from the test site of high arsenic level groundwater in Datong Basin were used to investigate the content of bioavailable arsenic and interaction with environmental conditions. The results showed that the contents of Al and Fe were high in these alkaline sediments. Amorphous and poorly crystalline of As with Fe and Al oxides were dominant and followed by residual phase in these sediments. It was 53.54% of all arsenic speciation for Fe and Al oxides containing arsenic, only 14.33% for adsorbed arsenic. Therefore, content of bioavailable arsenic was low in the sediment samples, which was consistent with the result of vitro simulative assay. We also found from vitro simulative assay that the content of bioavailable arsenic was lower in intestine phase than in the stomach phase. The concentration difference of bioavailable arsenic is low between physiologically based extraction test (PBET) and vitro gastrointestinal method (IVG).

Key words: As speciation, bioavailability, shallow aquifer, sediment, Datong Basin