Assessing the performance of wax-based microsorbents for oil remediation

Abstract

Millions of tons of crude oil are drilled from onshore and offshore locations to satisfy the yearly global fuel demand, increasing the risk for spills and major ecological disasters. Remediation strategies involving chemical surfactants and oil burning are employed, but the toxicity and undesired environmental effects of these treatments raise more concerns and prompt the investigation for alternative approaches. Amongst these novel methods are organic sorbents. In addition to being cost-effective, these materials absorb oil molecules and facilitate oil recovery in an eco-friendly manner. Here, we explore the ability of organic microparticles to improve oil spill clean-up with a focus on interfacial properties and sorption capacities. We investigate the potential of soy, soy-bee and carnauba waxes as secondary oil remediation technology. The waxes are used to design hollow-core microcapsules, which confer them a superoleophilicity ideal for oil recovery. The wax-based microcapsules can remediate oils, including crude oil, mineral oil, and hexadecane, with a sorption capacity up to 5 times their dry mass. Due to low density and high hydrophobicity, the oil-laden microparticles float on top of the water, easing the collection process. Thus, this study lays the foundation for the development of the new class of wax-based microsorbents, exhibiting attractive physical properties in addition of being made of FDA approved plant and animal derivatives. Future studies involving microparticle-assisted bioremediation will provide new insights on how the design of the microparticles could be tailored to fit various ecosystems.