[2M12-17] Bentonite

4:05 PM - 4:20 PM JST(7:05 AM - 7:20 AM UTC)

[2M14] Numerical Simulation of Ion Exchange Behavior in Buffer Materials Considering the Chemical Effects of Saltwater(2) Numerical Simulation of Infiltration Experiments

*Kazuya Ono¹, Tsuneyuki Maemura¹, Ryo Itoh¹, Ryo Yasuda², Shingo Tanaka², Daisuke Hayashi² (1. Dia Nippon Engineering Consultants, 2. RWMC)

Keywords:

geological disposal,coastal area,bentonite,solute transport,ion exchange analysis

To develop a numerical analysis method capable of predicting the adsorbed cation composition of buffer materials infiltrated with saline groundwater, we conducted numerical reproduction of infiltration tests in which compacted bentonite was infiltrated with coastal groundwater or artificial seawater. The coupled analysis of saturated-unsaturated seepage flow, advection-dispersion, and cation exchange equilibrium was used, and the Ca, K, and Mg cation exchange selectivity coefficients for Na used in the analyses were obtained from the compacted bentonite experiments.The analytical results showed good reproducibility with the test results, both in terms of effluent concentration and adsorbed cation composition. These results suggest that this method can be used to predict cation exchange in buffer materials infiltrated by saline groundwater.