Oxidation of Pyrite in Marine Clays and Zinc Adsorption by Clays

摘要

The oxidation of pyrite in marine clays exposed to a subaerial environment was confirmed and was determined to be well correlated with decreased adsorption of zinc by the clays. The production of sulfuric acid and iron oxide by this oxidation and the accompanying decrease in pH was demonstrated based on an investigation of the chemistry of the marine clay profile and laboratory incubation tests for remoulded clay samples. Both pH decrease and the production of iron oxides reduced the zinc adsorption capability of the clays. This suggests that the zinc adsorbed by the marine clays would be released into the pore water due to exposure of the sediment surface to the atmosphere.