Evaluation of the Phytoremediation of Robinia pseudoacacia L. in Petroleum- contaminated Soils with Emphasis on the Some Heavy Metals

Petroleum is a complex mixture of thousands of hydrocarbon and non-hydrocarbon compounds, including heavy metals which potentially are carcinogenic and mutagenic. Phytoremediation has been shown to be effective for degradation or removing petroleum contaminants. Selection of plant species for phytoremediation, however, is complicated. The effects of petroleum pollution of soil (0%, 1%, 2%, 3% and 4% V/W) on the proline, total protein, lead, cadmium and zinc contents in Acacia leaves were investigated using methods of Bathes, Bradford and Atomic Absorption, respectively. The data were statistically analyzed using SPSS v11 and Duncan’s test. The results showed that the total protein and proline contents increased significantly (p≤0.05) as the level of pollution increased. The highest proline content was measured at 4% treated plants. Proline accumulation is a common physiological response in many plants against a wide range of biotic and abiotic stresses. The results showed that lead and zinc accumulated by leaves. The leaf lead values were markedly, 20.8-fold, enhanced in 1%. There was not significant differences among cadmium levels in treatments and the control plants. Based upon these results, Robinia pseudoacacia L. can be used as bioaccumulator in petroleum pollution and were selected for the further investigation of the phytoremediation of pb-contaminated soil.