Electrokinetic Remediation of Soils Contaminated by Cationic Metals: —Influence of Pulse Voltage on Soil Acidification and Remediation Efficiencies@@@―パルス波形電圧が土壌酸性化および浄化効率に及ぼす影響―

Abstract

The objective of this study was to investigate the influence of pulse voltage on acidification and remediation efficiencies of soils contaminated by lead, cadmium, and magnesium. To achieve this objective, a series of bench-scale electrokinetic experiments was performed under the conditions in which the soil pH was gradually decreased from the cathode side. The electrokinetic experimental results demonstrated that the majority of soil pHs were below 4.0 after 36 hours energization and correspondingly, all cationic metals investigated in this study were migrated toward the cathode. Regarding the influence of pulse voltage, the electrokinetic experiments in which a pulse voltage (3 hours ON, 3 hours OFF) was applied demonstrated that applying the pulse voltage did not provide neither positive nor negative influences on the soil acidification and electricity consumption for removing three metals. It was also demonstrated that applying a pulse voltage (2 seconds ON, 2 seconds OFF) negatively affected the remediation performance with respect to the electricity consumption when compared to the case in which constant voltage was applied.