This is an award to support research on a comprehensive modeling approach for predicting metal ion sorption over the range of solid to solution ratios found in natural environmental systems. The model must be capable of predicting the distribution of surface complexes as a function of solids concentration and pH and should incorporate the effects of particle interactions on sorption phenomena. X-Ray absorption spectroscopy and atomic force microscopy will be used to determine the structure of surface complexes as a function of solids concentration in batch and recirculating batch reactors. The proposal leading to this award was submitted in response to NSF 88-99 as modified by changes dated 09/19/91 to make the Research Initiation Award announcement consistent with changes in NSF 83-57 and published as NSF 90-77. Many environmental problems associated with energy and raw material production require reliable quantitative prediction of the transport and dispersion of contaminants in surface and groundwater systems. Reaction of contaminant solutes with mineral surfaces in soils, sediments, and rocks typically causes a portion of each solute to partition onto the solids. This sorption decreases solute mobility, which must be accounted for in transport models. Results of this research are expected to be used to formulate surface complexation reactions and the resulting model will be used to simulate the sorption behavior of metal ions in column reactors used in design of environmental pollution abatement processes and systems.
