Assay of Aliphatic Hydrocarbons in Soils from Selected Areas in Ughelli and its Environs, Delta State, Nigeria

Abstract

Wisdom Ivwurie, and Oghenetega E. Okorodudu

The distribution pattern of aliphatic hydrocarbons (AHCs) was determined in soils and pure hydrocarbon compounds from selected areas in Ughelli and its environs (Delta State, Nigeria) were investigated in this work. The AHCs were quantified with gas chromatography equipped with a flame ionization detector (GC-FID) after extraction and cleanup with n-hexane. Sample collection for soils was from the surface (0-10cm) at various vicinity suspected to be polluted (i.e mechanic workshop, compound with usage of so much generator, flow-station environment, motor-way and filling station), while a control sample was also collected from virgin farmland. The pure hydrocarbon compounds which included diesel, fuel, carbon soot and spent engine oil were used to compare the concentration of AHCs present in the soil. The evaluated concentration of AHCs (nC_8-nC₄₀₎ ranged from 321,515 to 5,368,702 mg L^-1 and 27.42 to 16733 µg kg^-1 for pure hydrocarbon compounds and soils respectively. The concentration of n-alkanes in the soil samples showed some variations with contamination sources for different locations and consequently defined the trend, mechanic workshop soil > generator compound soil > flow-station soil > motorway soil > filling station soil. The molecular indices for aliphatic hydrocarbons showed that the aliphatic hydrocarbons in the soils might have originated from different anthropogenic sources.