Biochemical and physicochemical assessment of the efficacy of some wild-type legumes in the remediation of crude-oil contaminated soils

摘要

The efficacy of three wild-type legumes in the remediation of agricultural soils contaminated with 1% (lightly impacted), 3% (moderately impacted), and 5% (heavily impacted) crude-oil was assessed, using soil physicochemical and biochemical properties (soil quality indicators) as evaluation criteria. Results after a 15-month remediation period showed that only L. leucocephala failed to germinate. The level of MC (87%) as well as the activities of Lipases (103%) and ALPs (90%) in the P. pterocarpum-remediated soil samples were significantly (p0.05) elevated, relative to their respective contaminated samples, while the TPH (60%), was significantly (p0.05) reduced. The C. retusa-remediated soils had the level of MC (48%) and the activities of Lipases (59%) and ALPs (73%) significantly (p0.05) elevated, relative to the respective contaminated samples, while the level of TPH (65%) was significantly (p0.05) reduced. The levels of pH, and TOC as well as the activities of the dehydrogenases and ACPs were not significantly (p0.05) different from their corresponding contaminated samples remediated by both legumes. These results indicate that Leucaena leucocephala ‘may’ not be a good crude-oil remediating leguminous plant, while both Peltophorum pterocarpum and Crotalaria retusa are good crude-oil remediating leguminous plants.