Authors
Sara Beth Denison
Publication date
2022/8/12
Description
Terrestrial oil spills significantly outnumber marine oil spills every year. Exposure to crude oil spills is detrimental to human and environmental health and needs fast remediation. Pyrolytic treatment of crude-oil contaminated soils offers great potential for rapid remediation without destroying soil fertility, with lower energy requirements and costs than other thermal treatments (ie incineration). This study incorporated clays impregnated with non-toxic transition metals (iron or copper) as an amendment to decrease the required pyrolytic treatment time and temperature. We found that amending a weathered crude-oil contaminated soil with 10%(by weight) of bentonite, which had been modified via ion-exchange with either Fe or Cu, achieved significant TPH removal at pyrolysis temperature of 370 C and, unprecedentedly, at 300 C with 15-min contact time. The catalytic role of the metal ion-exchanged clays was validated using thermogravimetric analysis coupled with mass spectrometry, which revealed markers of pyrolytic degradation products of crude oil at lower temperatures than those observed for unamended soil. This work shows proof of concept that metal-impregnated clays can enhance rapid pyro-catalytic treatment of crude-oil contaminated soils, and encourages further work to understand the detailed reaction mechanisms to inform process design.