Temperature Effect on Desorption Kinetics of Benzene on Various Soils

Existing remediation techniques of petroleum contamination often take many years to achieve regulatory levels and require high operating costs with complicated logistics. The possibility exists that increased remediation efficiency of petroleum — contaminated soils can be accomplished at temperatures less than 80 °C, while not significantly increasing cost or complicating remediation operation. To this end, a batch testing program was developed to assess the viability of increased temperatures on the desorption efficiency of benzene on a fine-grained sand, kaolinite, and a natural soil (silty sand). Samples first underwent sorption testing at 20°C, before being subjected to desorption testing at 20, 40, 60, and 80°C respectively. Testing results support the hypothesis that increased temperatures lead to higher desorption efficiency. Results indicated 40°C as the optimum temperature to achieve a balance of increased efficiency with minimal cost increase. The sorption and desorption kinetics are discussed in view of soil type, organic content, and contamination level.