Phosphogypsum chemistry under highly anoxic conditions

摘要

Phosphogypsum (PG), primary byproduct form phosphoric acid production, is accumulated in large stockpiles and occupies vast areas of land. Contaminants emanating for PG stacks can impact the environment including waterbodies. The major constraint for PG use in the environment is the presence of metals in high concentrations. Reduction of sulfate found in PG and significance of sulfide production in reducing aqueous concentrations of toxic metals were studied. Mississippi River alluvial sediment amended with PG was equilibrated under controlled redox (-250 mV) and pH (5.5, 6.5, and 7.5) conditions.