Bioremediation and phytoremediation of oil spill in Niger Delta – A case study of Eriemu in Delta State

Abstract

Bioremediation of oil spill was investigated to determine the degradation of petroleum hydrocarbons released into soil and water.  The impacted area was divided into two blocks, A and B represented heavily and moderately polluted areas respectively, Block C, an unimpacted area represented control block.  The total petroleum hydrocarbon (TPH) and the microbes content at different depth were determined for each block.  The result of initial profile study was used as a guide to divide the soil horizon into four depth intervals.  Excavation was carried out on each block to 2m depth and the excavated materials from each interval were laid on PVC sheets as biopiles 1, 2, 3 and 4.  Seeded microbes were applied according to nutrient formulation needed to degrade the level of TPH in each pile.  Water hyacinth trained and genetically modified was used in aqua cells to treat pumped groundwater before re-injection into the soil.  Continuous monitoring of bioremediation carried out on biopiles and groundwater shows that the TPH reduced to less than 100pmm, and 0ppm respectively within 8 weeks.  The pH of the soil piopiles and groundwater was maintained the natural range (6-8) over the same period.  Heavy metal concentration in the impacted soil blocks showed no significant differences and they existed and concentration levels far below 2500pmm at  which microbial physiological activity can be affected.  The effect of solar energy, though not investigated, but could not be ruled out under this circumstance.