Electrokinetic remediation of chromium-contaminated saline soil coupled with permeable reactive barrier of biochar

This study examines the effects of EDTA, permeable reactive barrier (PRB) and location of PRB on decontamination of a high saline soil using electrokinetic remediation method. The material of PRB was particles of biochar made of barberry branch. The remediation system consisted of a plexiglass cell with cross area of 10 × 10 cm² and length of 12 cm as soil/PRB chamber, which was placed between catholyte and anolyte chambers. The thickness of PRB was 1 cm or 4.8% of the soil chamber. A voltage gradient of 1 V/cm was applied for 48 h. The solutions of electrolytes were distilled water and EDTA, and PRB was located in near catholyte and anolyte, and middle of soil cell. The results showed the removal efficiency of Cr(VI) was higher than 99% in all experiments. Application of EDTA as electrolyte decreased removal efficiency of Cr from the soil. Employment of PRB enhanced removal efficiency of total Cr form the soil, when it was located close to catholyte (65.8%) or anolyte (63%). The findings revealed that electrokinetic remediation coupled with PRB had not high efficiency for eliminating total Cr and Cr(VI) from a high saline soil.