title: Modeling kinetics of Cu and Zn release from soils.
abstract: Kinetics of Cu and Zn release from soil particles was studied using two surface soils with a stirred-flow method. Different solution pH, dissolved organic matter (DOM) concentrations, and flow rates were tested in this study. A model for kinetics controlled sorption/desorption reactions between soils and solutions was globally fit to all experimental data simultaneously. Results were compared to a model that assumes local instantaneous equilibrium. We obtained one unique set of model parameters applicable to different pH, dissolved organic carbon (DOC), and flow conditions. We included DOM complexation of copper ions, which decreased their sorption. The effect of pH was included by assuming proton competition with metal ions for binding sites on soil particles. These results provide the basis for developing predictive models for metal release from soil particles to surface waters and soil solution.
authors.affiliation: Center for the Study of Metals in the Environment, Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: Zhenqing
authors.initials: Z
authors.lastname: Shi
authors.forename: Dominic M
authors.initials: DM
authors.lastname: Di Toro
authors.forename: Herbert E
authors.initials: HE
authors.lastname: Allen
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Ponizovsky
mesh_terms: D002244:Carbon / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D012987:Soil / Q000032:analysis*; D015032:Zinc / Q000737:chemistry*
chemical_list: D012987:Soil; D002244:Carbon; D003300:Copper; D015032:Zinc