Comparative Study of Heavy Metals and Total Petroleum Hydrocarbon Concentrations in Remediated and Non-Remediated Crude Oil Contaminated Soil

Abstract

Abstract: The discharge of crude oil products to the environment (soil, water and air) has great negative impacts on the ecosystem. Most of these effects are from heavy metals, total petroleum hydrocarbons (TPH), polyaromatic hydrocarbons (PAH) among others. The aim of this research is to assess the effectiveness of the remediation on impacted soil through comparative analysis, and provide a recent data base on the pollution status of the soil. A stratified and random method of sample collection was adopted. From the three locations in Nkelleoken community, the result from the remediated soil showed that the greater amount of almost all the metals are bounded to F4 and F5 which are non-bioavailable to plants. Meanwhile the one from non- remediated soil is the opposite. The total petroleum hydrocarbon (TPH) results from the non-remediated soil samples were comparatively larger than that of the remediated soil (from 418.30±42.13 to 502.68 mg/kg). Whereas the TPH values from remediated site ranged from 193.65±37.20 to 207.0.4±70.14. Compared to the WHO standard (100-300 mg/kg) the TPH in the remediated soil were below the background limit. Microplasma Atomic Emission Spectroscopy and Total Petroleum Hydrocarbon Analyzer were used for the quantification of the inorganic and organic pollutants.