Evaluation of Removal Behavior of Cesium in Contaminated Soil Based on Speciation Analysis

The removal efficiency of Cs from contaminated soil depends on its chemical species bound with the soil components. Therefore, in this study, we observed the elution behavior of Cs based on speciation analysis in a Cs removal experiment conducted on contaminated soils. The treatment method was optimized using simulated contaminated soil and applied to actual contaminated soil on a large scale as well. The elution rate of Cs was approximately 50% or more in both actual and simulated contaminated soil using the optimized treatment method. From the obtained results, a robust treatment method using an eluting reagent and a magnetic adsorbent with low energy costs is proposed. Additionally, the usefulness of speciation analysis in decontamination studies was confirmed.

Enhancement Effect of Humic Acid on Removal of Lead from Soil by Electrokinetic Process

The environmentally friendly electrokinetic process was investigated using model contaminated soil with Pb and humic acid. Although humic acid has a negative charge, it moved toward the cathode side by electroosmotic flow. The removal efficiency of Pb from model contaminated soil was 48.0% under 1 V/cm of the potential gradient after 72 h of operation, while it improved to 72.6% with humic acid. These results indicated that humic acid has high potential for application in the environmentally friendly remediation of soil.