Sr(II) Removal from Aqueous Solution by Pseudomonas Fluorescens Biomass, Equilibrium and Kinetic Studies

Batch experiments were carried out to determine the capacity of Pseudomonas fluorescens biomass to adsorb Sr(II) ions from aqueous solution with respect to pH, initial Sr(II) concentration, contact time and biomass dose. The FTIR results of Pseudomonas fluorescens biomass showed that biomass has different functional groups and these functional groups are able to react with metal ion in aqueous solution. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Sr(II) was 80.06 mg/g. The pseudo-first order and pseudo-second order models were used to describe the kinetic data and to evaluate rate constants. The best correlation was provided by the second-order kinetic model, implying that chemical sorption was the rate-limiting step. The practical implication of this study is the development of an effective and economic technology for Sr(II) removal from contaminated waters.