Pore water chemistry of phosphogypsum-treated soil

Phosphogypsum (PG) is a gypsum-based by-product of phosphate fertilizer production and is commonly stored at plant sites. As stockpiles of the material accumulate worldwide, elemental leaching from repositories is of potential environmental concern. In this study, samples of glacial till, PG, and mixtures of the two were incubated with deionized water. Solution extracts were analyzed for chemical constituents. Speciated activities of Al, Cr, and Cu, obtained using GEOCHEM, were related to theoretical levels estimated from solubility constants of potential solubility-controlling solids []