Assessing the Effectiveness of Land farming in the Remediation of Hydrocarbon Polluted Soils in the Niger Delta, Nigeria

Hydrocarbons pollution of soils has constituted environmental issues over the years. The biggest concern associated w ith hydrocarbon pollution in the environment is the risk to farmlands, fisheries and potable water supplies contamination. Several remediation techniques exist (Bioremediation and Non-bioremediation), which aim at reducing the hydrocarbon content of the polluted soil and water with their varying degrees of success. Thus land farming, one of the bioremediation remediation techniques is view ed as a more viable remediation options for hydrocarbon polluted soils. The study therefore was instituted to assess the effectiveness of land farming (Enhanced Natural Attenuation) in the remediation of hydrocarbon polluted sites in the Niger Delta. Soil samples from ten (10) sites polluted and remediated sites in the Niger Delta; that is five (5) samples each from the swampy and well drained sites and subjected to Laboratory analysis. The results were further analysed using both descriptive and inferential statistical tools of percentages, regression analysis and student t-test. The results of the soil analysis show 14.54 to 82.24% and 16.01 to 50.54% reductions in the TPH and PAH concentrations after land farming respectively. This shows high level of efficacy in the use of the Land farming as remediation technique. However, the efficacy varied between the swampy and well drained soils; reductions in the hydrocarbon levels of the soils in the water-logged or swamp areas were lower and slower than that of the well drained soils. This shows that the soil microbes were able to degrade the hydrocarbons faster in the well-drained soil probably because of the favourable soil conditions like pH, moisture, and nutrient. To ameliorate this problem, more effective way of bio-remediation for swamp area should be pursued like phyto-remediation; this is the use of higher plants to enhance the remediation of soils contaminated with recalcitrant organic compounds.