Sorption of heavy metals and radionuclides on mineral surfaces in the presence of organic co-contaminants. 1998 annual progress report

摘要

This project is designed to determine how organic chelating ligands can influence the partitioning of ionic solutes (heavy metals and radioactive isotopes) between the solution phase and metal-oxide surfaces. Equilibrium states and kinetics of partitioning in these ternary systems will control contaminant transport and bioavailability of the ligands and contaminant metals in groundwater. As a result, this work represents a significant contribution toward efforts to develop predictive modeling for the transport and transformation of groundwater contaminants. Uranium(VI), strontium(II) and lead(II) have been chosen as representative of high priority pollutants at DOE and non-DOE sites. Strontium in particular has received relatively little detailed attention in the literature. Mineral surfaces chosen for this project include goethite, gibbsite, and kaolinite. The organic chelators--EDTA, NTA, and citric acid--are components of both DOE and industrial wastes. In addition, citric acid is found naturally as a product of metabolic processes in soils and groundwater.'