Investigation the Kinetic Models of Biological Removal of Petroleum Contaminated Soil Around Oil Pipeline Using Ryegrass

The industrial revolution of the past century has resulted in significant damage to environmental resources such as air، water and soil. Petroleum contamination of soil is a serious problem throughout the oil producer countries. Remediation of petroleum contamination of soils is generally a slow and expensive process. Phytoremediation is a potentially less-damaging، cost-effective، but needs longer-term for remediation of contaminated land compared to the alternative methods. In this study the kinetics of petroleum hydrocarbon contaminated soils in Khozestan were investigated. For this paper Ryegrass (Lolium perenne) plant selected and the decline of total petroleum hydrocarbon (TPH) was analyzed after growth stage، every 10 days up to 90 days. The results of TPH concentration was fitted with zero-order kinetic، first-order kinetic and Higuchi model. The result indicated that degradation of TPH with presence of plants as a function of time was well fitted with the first-order kinetic model. The first-order rate constants (K) and half-lives (T1/2) for TPH degradation were 0. 0098 1/day and 71 day; respectively. The results of phytoremediation showed that there were 65% decreases in TPH concentration with Ryegrass during the 17 weeks.