Physical Sciences and Mathematics Commons^™

Seawater-Induced Mobilization Of Trace Metals From Mackinawite-Rich Estuarine Sediments, Vanessa Wong, Scott Johnston, Edward Burton, Richard Bush, Leigh Sullivan, Peter Slavich

Associate Professor Edward D Burton

Benthic sediments in coastal acid sulfate soil (CASS) drains can contain high concentrations (∼1–5%) of acid volatile sulfide (AVS) as nano-particulate mackinawite. These sediments can sequester substantial quantities of trace metals. Because of their low elevation and the connectivity of drains to estuarine channels, these benthic sediments are vulnerable to rapid increases in ionic strength from seawater incursion by floodgate opening, floodgate failure, storm surge and seasonal migration of the estuarine salt wedge. This study examines the effect of increasing seawater concentration on trace metal mobilization from mackinawite-rich drain sediments (210–550 μmol g⁻¹ AVS) collected along an estuarine salinity …