Surfactants and Their Applications for Remediation of Hydrophobic Organic Contaminants in Soils

Abstract

Soil contaminated with ubiquitous hydrophobic organic contaminants (HOCs) is a worldwide recurring concern arising from their indiscriminate disposal, improper management, and accidental spills. A wide range of traditional remedial strategies have been the common practice. However, these treatment methods have become cost prohibitive, not environmental friendly, and less accepted by society. Surfactant-enhanced remediation technology represents a cost-effective and green technology alternative to remediate such contaminated sites. Surfactant remediation technologies are conducted in-situ or ex-situ as two broad categories, or in combination. Among these technologies are soil flushing, washing, phytoremediation, and bioremediation. More applied research continues to quantify the efficiency of surfactant-enhanced mass transfer phase using a single surfactant solution while their binary blends to remove mixed HOCs in soils are also a focus of interest for research. There is a great potential to develop novel synthetic and biosurfactants that will exhibit higher biodegradability, less toxicity, higher removal efficiency, more economical and more recyclable. This work thus provides a review of the applications and importance of surfactant-enhanced remediation of soil contaminated with HOCs. Relevant environmental factors, soil properties, surfactant chemistry, mechanisms, mass transfer phase, and field designs are summarized and discussed with purposes of providing greater context and understanding of surfactant-enhanced remediation systems.