An investigation into solvent extraction of PCBs from weathered soils

Laboratory investigations were conducted to study the efficiency of extraction of polychlorinated biphenyls (PCBs) from weathered soils by polar organic solvents i.e. acetone, isopropanol (IPA) and methanol that were chosen for lower hazard and for penetration in wet soil. The impacts of hydrogen peroxide pretreatment, soil-solvent ratio and number of extraction cycles on PCBs extraction efficiency were investigated. The pretreatment of soil with hydrogen peroxide (H2O2) prior to extraction improved PCB extraction efficiency. An enhancement in extraction efficiencies was also observed with an increasing number of extraction cycles and at lower soil-solvent ratio. All three solvents could recover Aroclor 1254 (> 73%) from the weathered soils with muiticycle extractions.