Leaching Assessment of PAHs from Oil Contaminated Sites

Polycyclic aromatic hydrocarbons are in amongst of the most important environmental pollutants. Their leaching from soil into groundwater is one of the most important environmental concerns. Considering the high volume of activities in oil industry، many sites have been contaminated with oil compounds in Iran. Since soil remediation costs are very high، making a decision about remediation or not remediation of the oil polluted soils needs a careful assessment. Column leaching test was applied in the current research as a modern and effective tool to predict leaching of PAHs from soil. In order to do this procedure، the contaminated soil from south of Tehran city (near the oil refractory) were prepared. Then، dried in the air and sieved from 2 mm. The material of soil was silt and clay; also had a 1. 81 percent organic carbon. The tests were done in glass column with 600 cm3 capacity (6 cm diameter، 21 cm high). Results showed that only a small part of available PAHs in solid phase (soil) leached into water and high concentration of PAHs in the solid phase dose not necessary imply serious groundwater contamination risk and significant amount of PAHs may stay in the soil for a long time.