Removal of radioactive Cs using aqueous sodium metasilicate with reduced volumes of waste solution

Remediation of materials contaminated with a radioactive material such as Cs-137 is important. Here, we report on the effectiveness of an aqueous sodium metasilicate prepared with a microbubble crushing process (SMC) for the removal of radioactive Cs-137 from granule conglomerates and nonwoven cloth. A Cs-137 removal ratio of 78% was achieved for the nonwoven cloth sample, and multiple washings at low SMC concentrations were effective. In addition, the volume of the waste solution could be reduced by neutralizing the SMC and using gelation to remove the radioactive material. The decontamination is shown to be more efficient than that with sodium hydroxide, even for washing granule conglomerates.