Effect of pH control on electrokinetic remdiation of a fine textured soil contaminated with crude oil

These days, one of the most important environmental problems is soil pollution due to the contamination by petroleum hydrocarbons. One of the methods for reducing of soil contamination is the use of the electrokinetic process for remediation of hydrocarbons contaminated soils. Electrokinetic process causes the movement of water, ions and charged particles in the soil by electric field voltage. In this study, the effect of pH control in catholyte and anolyte on electrokinetic for removal of petroleum hydrocarbons from a clay soil, was evaluated. For this purpose, two experiments; one without pH control and second with pH control (in the range of 6-9) in electrolytes were carried out. Initial concentration of petroleum hydrocarbons in soil was 5%. The amount and type of petroleum hydrocarbons in the soil samples were measured by GC-MS. The results of both experiments showed that after 30 days, and 1 Vcm-1 electric field voltage, the highest percentage hydrocarbons was near anodes with little movement in the middle column. The average of petroleum hydrocarbons removal of two experiments was 16.67% and 31.5%, respectively. In addition, in the second experiment, about 26% of paraffin hydrocarbon and 37% of naphthalene hydrocarbons were removed from the soil column.