Impact of ultrasonication time on elution of super heavy oil and its biomarkers from aging soils using a Triton X-100 micellar solution

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 (0–1800 s) on the elution of super heavy oil and its three characteristic biomarkers (C 26–34 17α 25-norhopanes, C 26–28 triaromatic steroid [TAS], and C 27–29 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 C 26–34 17α 25-norhopanes, the smaller molecules were more readily eluted during 0–360 s ultrasound. This trend was reversed upon application of ultrasound during 1080–1800 s, with improved elution of larger molecules and elution followed a similar second-order function. For C 26–28 TAS, smaller molecules were more readily eluted but the elution of larger molecules followed a similar second-order function. For C 27–29 MTAS, elution of larger molecules was close to that of C 26–34 17α 25-norhopanes. Results of SEM and XRD indicated that the mineral and chemical compositions of soils eluted at ultrasonication times of 1080–1800 s closely resembled clean soils.