Effect of Urea Application on Soil Properties and Hydrocarbon Reduction in Crude Oil Contaminated Soil

Background and Objective: Soil contamination resulting from crude oil spills poses an environmental threat in the Niger Delta Area of Nigeria and the world at large and the remediation of oil-polluted soil is one of the major problems for environmental research. This study investigated the effect of urea as an amendment (remediating material) on soil properties and hydrocarbon reduction in crude oil-contaminated soil at Botem-Tai in Rivers State, Nigeria. Materials and Methods: A Randomized Complete Block Design (RCBD) was used and the experimental treatment were: B1: Polluted soil without urea, B2: Polluted soil with 20 g urea addition, B3: Polluted soil with 40 g Urea addition, B4: Unpolluted soil. Physical-chemical and microbial analyses were done on soil samples from the different treatment plots. Results: The significant reductions (p = 0.05) in Total Hydrocarbon Content (THC) and Total Petroleum Hydrocarbon (TPH) of polluted soil with urea addition (B2: 193.98 and 135.90 mg kg‾1 and B3: 708.13 and 615.40 mg kg‾1) compared to the polluted without urea (B1: 1963.67 and 1014.37 mg kg‾1) as against the initial of 2926.00 and 1189.96 mg kg‾1 recorded. Conclusion: Hence, the use of urea in in situ remediation of crude oil-polluted soil proved effective.