Sorption of natural dissolved organic matter on soil

Experiments in batch soil/aqueous systems were conducted to evaluate the im portant physical-chemical factors determining the sorption of dissolved org anic matter (DOM) onto natural soil. This information is critical to unders tanding the fate and transport of contaminants in subsurface. Results obtai ned from this study indicate that DOM sorption on soil is largely due to li gand 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 capacit y of DOM appears to be positively correlated to the soil clay content as we ll as the soil water solution ionic strength and pH.