Rapid Assessment of Petroleum Hydrocarbon Contamination in Soils: Spectroscopy Approach

Soil contamination with total petroleum hydrocarbons (TPH) as a result of crude oil exploration and exploitation activities is currently a major environmental challenge. This study proposed diffuse reflectance spectroscopy as a viable technique for rapid assessment of hydrocarbon contamination on oil spill sites in the Niger Delta, Nigeria. Spectroscopy approach was carried out in the laboratory for the prediction of TPH concentrations (mg kg-1) in genuine petroleum contaminated soils (fresh wet), as compared with analytically measured TPH concentrations. Very strong positive correlation (r = 0.9686) was achieved between analytically and spectroscopically-predicted TPH (mg kg-1). Actual and predicted absorbance (ABSact and ABSpred, respectively) values were determined and appear not to be consistent. However, very strong positive correlation appears when each of parameter was plotted against measured TPH concentration. Diffuse reflectance spectroscopy methodology was found to be as good as the labour-intensive and expensive traditional laboratory analysis of soil PHCs and could be an alternative for laboratory methods and as a viable field-screening tool to enhance risk decision making on-site.