Response surface methodology for the modelling of ⁸⁵Sr adsorption on zeolite 3A and pumice

Abstract

The adsorption of ⁸⁵Sr from aqueous solutions on to zeolite 3A and three types of pumice materials (i.e. Kayseri, Isparta and Nevsehir) was investigated in this study. Experiments with radioactive ⁸⁵Sr were performed to test the sorption ability of the sorbents to remove this radioisotope from liquid radioactive wastes. The influence of sorbent dosage and initial activity of feed solution on the decontamination factor were analysed and optimized by means of response surface methodology. The parameters of the experiments, namely temperature, pH, time, stirring efficiency, were selected in preliminary tests. The experimental results showed that the most efficient pumice sorbent for ⁸⁵Sr is Isparta, for which a maximal decontamination factor of 76.92 was obtained by using the sorbent dosage of 0.5% w/v. However, the commercial zeolite 3A was 2.71-fold more efficient than Isparta pumice for decontamination of strontium radioactive solutions. Isparta pumice is a low-cost natural sorbent, and its ability to effectively bind strontium radioisotope from water solutions suggests that this material has further applications for radioactive waste treatment.

Keywords:

• zeolite
• pumice
• adsorption
• strontium
• response surface methodology

Acknowledgements

This research has been supported by the Marie Curie Transfer of Knowledge scheme of the 6th EU Technological Research and Development Framework Programme, AMERAC project (No: MTKD-CT-2004-509226) and The National Centre for Research and Development (NCBiR) Research Grant No. R05 0058 06/2009.