Determination of total petroleum hydrocarbons (TPHs) in weathered oil contaminated soil

Abstract

A new measurement method of weathered crude oil in soil was reviewed. There is no standard method for the extraction of crude oil from soil. Hence, a basic initial test was carried out and several methods such as gravimetric and gas chromatography-mass spectrometry (GC-MS) with various parameters such as weight, solvent and time. The gravimetric process was demonstrated to be the most effective for quantifying weathered contamination crude oil in contaminated soil. The dichloromethane DCM, mixture of DCM: hexane (1:1 v/v mix) and the mixture of acetone: hexane (1:1 v/v mix) were used to investigate the ability of solvent extraction technique for removing weathered crude oil from soil under various extraction conditions. The mixture of acetone: hexane (1:1 v/v mix) was demonstrated to be the most effective in removing total petroleum hydrocarbons (TPH) from contaminated soils. 5 g and 1 g weights of oil-contaminated samples were studied to select the best weight depending on contamination level. 1 g of contaminated soil was cleaned in three cycles whilst the 5 g of contaminated soil required six cycles. The selected parameters recovered about 97.20% of the weathered crude oil. These parameters were influenced with character of high efficiency, low cost, low toxicity, and short time.