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Abstract: An ultrasound-enhanced elution system with Triton X-100 solution was used to remediate aging soils contaminated with super heavy oil. We used GC/MS, SEM, and X-ray diffraction (XRD) to analyze the effect of ultrasonic time (0–1800s) on the elution of super heavy oil and its three characteristic biomarkers (C26–34 17α 25-norhopanes, C26–28 triaromatic steroid [TAS], and C27–29 methyl triaromatic steroid [MTAS]). The oil and biomarkers remaining in the treated soils followed similar second-order functions with increasing ultrasonication times. Biomarker elution was closely related to carbon numbers in the marker. For C26–34 17α 25-norhopanes, the smaller molecules were more readily eluted during 0–360s ultrasound. This trend was reversed upon application of ultrasound during 1080–1800s, with improved elution of larger molecules and elution followed a similar second-order function. For C26–28 TAS, smaller molecules were more readily eluted but the elution of larger molecules followed a similar second-order function. For C27–29 MTAS, elution of larger molecules was close to that of C26–34 17α 25-norhopanes. Results of SEM and XRD indicated that the mineral and chemical compositions of soils eluted at ultrasonication times of 1080–1800s closely resembled clean soils. [Copyright &y& Elsevier]

Abstract: An ultrasound-enhanced elution system employing water at a temperature of 70°C was used to remedy weathered soils contaminated with severely biodegraded heavy oil (SBHO). The effect of varying the ultrasonic irradiation time from 0 to 1800s on the elution of SBHO and three characteristic biomarkers (C26–34 17α 25-norhopanes, C26–28 TAS, and C27–29 MTAS) was analyzed using GC/MS, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Elution of the three biomarkers was closely related to the carbon number of the marker. C26–34 17α 25-norhopanes and C26–28 TAS species with higher carbon numbers and C27–29 MTAS species with lower carbon numbers were more readily eluted using sonication times of 1080–1800s, while smaller TAS homologs were more readily eluted after sonication times of 0–360s. SEM images of samples treated for longer periods revealed larger “bare patches” on the soil surface. The results of XRD and energy spectroscopy experiments indicated that ultrasound irradiation for 1080s negatively affected the deposition of CaCO3, but overall improved the mineral and chemical compositions of treated soils and removal of SBHO. [Copyright &y& Elsevier]