COMPARATIVE STUDY OF CADMIUM,COPPER AND NICKEL ADSORPTION IN THREE BROWNFIELD SITES, NORTHWEST OHIO

The environmental and health effects of metals depend on the ability of the soil to immobilize them. Soils also influence bioavailability for plant uptake and the fate and transport of heavy metals. For these purposes, competitive adsorption of three metals of local concern: nickel, copper and cadmium in soils from three unlined landfill sites: Tiffin, North Cove and Treasure Island, all within Northwest Ohio, were investigated using laboratory batch equilibrium experiments. The soil was initially hypothesized to sorb nickel preferentially more than copper and cadmium based on previous monometal sorption characteristics. The samples were analyzed to determine the mass of metals adsorbed using Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES) at the laboratory of United States Department of Agriculture (USDA-ARS). The sorption data obtained were fitted into Langmuir and/or Freundlich models to determine the sorption maxima, bonding strengths and distribution coefficients of the soil with respect to the metal pollutants. The results were used to determine competition for vacant sites, affinity for sites, bioavailability together with leaching potential. The results also show a significant interaction between the metals, which invariably depends on the soil physicochemical properties, and clay mineralogy.