Comparative Studies of Biostimulation and Phytoremediation in the Mitigation of Crude Oil Toxicity in Tropical Soil

Abstract

Comparative studies of biostimulation using local materials and phytoremediation in the mitigation of crude toxicity on tropical soil of the Niger-Delta of Nigeria were carried out. 5% pollution level of crude oil were done alongside the control. Remediation treatments were done after one week of pollution using the following materials: Batch A : 20g of NPK 15:15:15; batch B: 50g of poultry dung; batch C: 5 seeds of Vigna unguiculata grown on the polluted soil (phytoremediation); batch D: control (pollution but no remediation); and batch E: double
control (no pollution and no remediation treatment). Soil analyses result indicated that the different remediation treatments have potentials to ameliorate crude oil toxicity at different degrees because of their ability to increase the nutrient content and decrease the total hydrocarbon content of the soil. There was no statistical difference in the soil
pH, Zinc and Copper contents between and within treatments throughout the study period. Highest crude oil biodegradation and improvement in nutrient content of the soil were observed in NPK 15:15:15 and phytoremediation treatments indicating that these are good remedial treatment options in the mitigation of crude oil toxicity