A COLUMN STUDY OF SOIL CONTAMINATION BY LEAD: INFLUENCE OF pH AND CARBONATE CONTENT. I. EXPERIMENTAL RESULTS

Abstract

The influence of soil carbonate content on the fate of lead in soil was studied in a lab-scale column under different pH values of the contaminant solution. Results indicated that retention of this toxic heavy metal (up to 38% weight at pH = 5) occurred which was proportional to the total carbonate content. A decrease in the pH of the aqueous solution entering the column resulted in a decrease of the retention of lead in the soil. Furthermore, the concentration of lead in the effluent was increased dramatically. Concentrations of lead about 2.5 times higher than in the contaminant solution were measured at pH = 3. Knowledge of these phenomena is important for risk assessment and remediation feasibility studies.

Keywords:

• Soil contamination
• Lead
• Carbonates
• Column studies

ACKNOWLEDGMENTS

Authors are in debt with D. Pedro Diaz Coca for his help in the setting up of the laboratory experiments.