Author(s)

Mohammad Rajib^1,2*, Taishi Kobayashi³, Chiaki T. Oguchi⁴, Takayuki Sasaki³

¹Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
²Bangladesh Atomic Energy Commission, Dhaka, Bangladesh.
³Department of Nuclear Engineering, Kyoto University, Kyoto, Japan.
⁴Department of Civil and Environmental Engineering, Saitama University, Saitama, Japan.

In-situ oxidation of solid phase was considered to investigate adsorption behavior under different geochemical parameters like pH, initial concentration and ionic strength. Pumice tuff, a potential host rock for low and intermediate radioactive wastes, has been affected by the redox zone. The characterization of the fresh and oxidized tuff was performed by X-ray diffractometer, scanning electron microscope and mercury intrusion porosimetry. In order to compare the difference of distribution coefficient (K_d) in fresh and oxidized pumice tuffs, a batch adsorption study was carried out at the range of pH (4 - 12), ionic strength (0.003, 0.1, 1.0 and 3.0 mol/dm³) and initial cesium concentration (10^-4, 10^-5, 10^-6 and 10^-7 mol/dm³). Based on experimental K_d values, ionic strength was found to be the most influential factor, whereas the effects of pH, initial Cs concentration and weathering condition of pumice tuff were negligible. The recalculated K_d values suggest that the existing surface complexation model is applicable to explain the sorption coefficients through the wide range of solution conditions.

Oxidation, Ionic Strength, Adsorption, Cesium, Batch Experiment, Distribution Coefficient, Pumice Tuff

Rajib, M. , Kobayashi, T. , Oguchi, C. and Sasaki, T. (2016) Oxidation of Solid Phase and Ionic Strength Effect to the Cesium Adsorption on Pumice Tuff. Journal of Geoscience and Environment Protection, 4, 64-73. doi: 10.4236/gep.2016.42008.