Physical Sciences and Mathematics Commons^™

Iron And Arsenic Cycling In Intertidal Surface Sediments During Wetland Remediation, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan

Associate Professor Edward D Burton

The accumulation and behavior of arsenic at the redox interface of Fe-rich sediments is strongly influenced by Fe(III) precipitate mineralogy, As speciation, and pH. In this study, we examined the behavior of Fe and As during aeration of natural groundwater from the intertidal fringe of a wetland being remediated by tidal inundation. The groundwater was initially rich in Fe2+ (32 mmol L−1) and As (1.81 μmol L−1) with a circum-neutral pH (6.05). We explore changes in the solid/solution partitioning, speciation and mineralogy of Fe and As during long-term continuous groundwater aeration using a combination of chemical extractions, SEM, XRD, and …