Sorption of natural dissolved organic matter on soil

Abstract

Experiments in batch soil/aqueous systems were conducted to evaluate the important physical-chemical factors determining the sorption of dissolved organic matter (DOM) onto natural soil. This information is critical to understanding the fate and transport of contaminants in subsurface. Results obtained from this study indicate that DOM sorption on soil is largely due to ligand exchange between DOM and hydroxyl groups on the soil mineral surface. Soil organic matter tended to impend the sorption of DOM, presumably due to blocking of active sites on the mineral surface. The soil sorption capacity of DOM appears to be positively correlated to the soil clay content as well as the soil water solution ionic strength and pH.