Keywords: soil contamination, petroleum hydrocarbons, terrestrial oil spills, ex situ technologies, environmental damage, in situ processes, nanoparticles, targeted delivery

Soil contamination by petroleum hydrocarbons is a global issue with deep environmental consequences. While ocean­ based oil spills receive the most news coverage, land oil spills actually make up the majority of oil spills worldwide. They result in the distribution of chemicals with potentially severe or chronic health effects to plants, animals and humans. It is necessary to treat soil impacted by spilled oil; however the process is often slow and costly because it is difficult to access the contaminants in the soil which are trapped below the surface. Most commonly, ex situ technologies are used which dig up the contaminated soil before treatment, though this results in environmental damage and has no long­ term sustainability.

Nanoparticle­ based in situ processes have the potential to deliver effective treatments while enabling sustainability by limiting environmental damage. By modifying the surface properties of nanoparticles, they can be designed to avoid interactions with clean soil and favour interactions with target contaminants. Therefore, the nanoparticles will move through clean soil and stick only to contaminated soil. This targeted delivery approach that we are developing in our lab promises to improve the efficiency, effectiveness, and economics of in situ soil remediation to offer practical alternatives to conventional ex situ technologies.