Effect of Phytoremediation on PAHs Levels of Agricultural Soil around Mechanic Village Wukari, Nigeria

This study evaluates the PAHs composition in agricultural soils around Mechanic village, Wukari using standard procedures by means of GC-MS. The possible source of the PAHs in the soil was deduced, using the diagnostic ratio analysis for PAH origin. Risk assessment was based on the incremental life cancer risk of PAHs proposed by Provisional Guidance for Quantitative Risk Assessment of the United States Environmental Protection Agency. Effect of phyto-remediation using Zea mays inter-planted with Striga hermonthica (SMV-MS), Zea mays alone (SMV-M), Zea mays inter-planted with Striga hermonthica alongside the application of fertilizer (SMV-MSF) and Zea mays alone alongside fertilizer application (SMV-MF). The result reveals that the PAHs composition based on ring prevalence in agricultural soils around Mechanic village Wukari was in the order Σ5 >Σ6 >Σ4 >Σ3 >Σ2 ring. Dibenz [a,h] anthracene 4.52 μg/kg (39.09%) has the highest percentage abundance but was less than the 100 μg/kg and 700 μg/kg Canadian soil quality guideline for agricultural and commercial layout while acenaphthene 0.111 μg/kg (0.90%) was the least abundant. The source of the PAHs in the soil was basically pyrogenic based on the diagnostic ratio analysis while phytoremediation of the soil using Zea mays inter-planted with Striga hermonthica significantly reduce the PAHs content of the soil.