Experimental Setup and Preliminary Results for Electron Beam Remediation of Heavy Hydrocarbon Contaminated Soils

Abstract

Electron beam soil remediation has been shown to be an effective method for reducing total petroleum hydrocarbon (TPH) of polluted soils. This is done through a combination of reaction mechanisms, including thermal effects, radiation induced chemistry, and physical effects. Based on preliminary experiments, electron beam (e-beam) reactors and reactor supports were designed for soil treatment. Initial screening experiments with manufactured soils indicated a dose-dependent TPH reduction to below 1% in some cases. Further experiments and commercial analysis of treated real soils for C5-C38 alkanes showed reductions to below 1% for Benchmark soils 1 & 2 and GSC1AOS soil. Maximum TPH reductions for real soils are 9.1% to 0.15% for GSC1AOS with an 1100kGy dosage, 2.9% to 1.2% for GSI14RD with a 720kGy dosage, 1.6% to 0.17% for BM1 with a 960 kGy dosage, 2.1% to 0.5% for BM2 with an 820kGy dosage, and 31.9% to 28% for BT Sludge with an 1100kGy dosage. Three additives, ethanol, potassium chloride (KCl), and citrus oil were tested in 5wt% amounts with BM1. 720kGy treated soils with additives showed a TPH reduction to less than 0.5%, lower than the predicted value of 0.69% from BM1 experiments without additives. TPH reduction due to e-beam treatment was shown to increase with dosage and treatment temperature but decrease with increasing moisture. Additionally, changes in the carbon number distribution indicate non-thermal effects from e-beam treatment and the production of hydrocarbon fractions available for removal by environmental exposure. Adding a condenser to the setup was shown to improve collection of separated liquids.