Fate of limestone dissolution products in acidic metalcontaminated soil mesocosms

Abstract

The impact of liming (10 t ha-1 of calcitic and dolomitic limestone, separately) on the soil solution and soil matrix was investigated in an acidic metal-contaminated soil from Sudbury, ON. A soil mesocosm experiment was performed; columns were leached with simulated rainwater and the soil solution collected at various locations throughout the soil column. The dissolution rate of calcitic limestone used for this experiment was found to be approximately double that of the dolomitic limestone investigated. Calcium and Mg released during limestone dissolution migrated through the soil profile to the Bf-BC interface. The addition of limestone increased the pH and decreases the bioavailability of Ni, Cu, Co, Cd, As, Ba, Mn, and Zn the LFH horizon. Amending acid, contaminated soils with calcitic or dolomitic limestone has profound effects on soil solution chemistry.