Biosorption of uranium(VI) from aqueous solution using phosphate-modified pine wood sawdust

Abstract

The phosphate-modified pine wood sawdust (PA-PWS) was used as a biosorbent for U(VI) adsorption from aqueous solution. FTIR analysis indicated that the carboxyl groups and the phosphate groups might be responsible for the adsorption of U(VI) onto PA-PWS. The equilibrium data were correlated with Langmuir and Freundlich models, and the maximum monolayer adsorption capacity obtained from the Langmuir model was 74.1 mg/g at 293 K. The influence of particle size, sorbent dosage, and U(VI) concentration on the adsorption kinetics was evaluated. In most cases, both the sorbent dosage and the metal concentration had great impact on the kinetic parameters (adsorption capacity and rate constant), while the particle size only had limited effect on these parameters.