Arsenic removal from natural groundwater using 'green rust': Solid phase stability and contaminant fate.

Arsenic (As) contamination in groundwater remains a pressing global challenge. In this study, we evaluated the potential of green rust (GR), a redox-active iron phase frequently occurring in anoxic environments, to treat As contamination at a former wood preservation site. We performed long-term batch experiments by exposing synthetic GR sulfate (GR) to As-free and As-spiked (6 mg L) natural groundwater at both 25 and 4 °C.