HR: 09:00h
AN: B31A-03    [Abstracts]
TI: Competitive Adsorption-Desorption Kinetics of Arsenate and Phosphate in Soils
AU: * Zhang, H
EM: hzhang@agctr.lsu.edu
AF: Hua Zhang, Department of Agronomy and Environmental Management, LSU, Baton Rouge, LA 70803
AU: Selim, H M
EM: mselim@agctr.lsu.edu
AF: Dr. H.M. Selim, Department of Agronomy and Environmental Management, LSU, Baton Rouge, LA 70803
AB: Phosphate competition on arsenate sorption can increase the mobility of toxic arsenic in soils and aquifers, leading to possible contamination of groundwater. Rate-limited adsorption-desorption of arsenate [As(V)] and phosphate (P) as well as their complex interaction makes the prediction of the fate and transport of arsenic in soil and water environment rather complex. In this study, kinetics of competitive adsorption-desorption of arsenate and phosphate was investigated in batch systems by introducing mixed As(V) and P solution at different concentration ratios to three soils having different properties, sampling at different reaction times, following by successive desorptions. Our results indicated that As(V) and P adsorption on soils were highly time-dependent, with decreased sorption rate with increasing reaction time. Rates and amounts of As(V) adsorption on soils were significantly reduced as increasing P concentrations presented. The three soils tested in our experiments exhibited different sorption affinity to As(V) and P, suggesting that specific sorption for As(V) or P by soils might play a significant role in their interaction.
DE: 1806 Chemistry of fresh water
DE: 4807 Chemical speciation and complexation
DE: 4857 Pollution
DE: 4866 Sorptive scavenging
SC: Biogeosciences [B]
MN: 2005 Joint Assembly