Arsenic adsorption and desorption processes downstream of a Fijian gold mine

摘要

Long-term discharge of treated tailings water from the Vatukoula/Tavua mining region of Fiji has dispersed arsenic (As) to the downstream NasiviRiver. Assessment of sediment contamination requires knowledge of As binding, particularly with iron oxides, as there may be a downstream health risk. Hydrous ferric oxides (HFO), e.g. ferrihydrite converting to goethite over time, are the most reactive sediment components for sorption or bonding as either as As~(3+) or As~(5+) (Goldberg, 2002). This study examines the adsorption and desorption characteristics of As in synthetic and Nasivi river sediments.