Surfactants: toxicity, remediation and green surfactants

Surfactants toxicity has induced a worldwide alert followed by various regulations. There are still concerns about the biodegradability and ecofriendliness of surfactants. Reviews on surfactants are available, but a concise manuscript covering surfactant types, primary and secondary toxicity of surfactants, evaluating the level of surfactant pollution worldwide, is needed. We review here the safety of surfactants in the aquatic system, in terrestrial ecosystems and for humans. We discuss strategies to solve surfactant contamination. Remediation methods include ozonation, UV radiation and catalyst-coupled auto-oxidation. We focus on the biodegradation of the anionic detergents sodium dodecyl sulfate and linear alkyl benzene sulfonate. Finally, the relevance and role of biosurfactants as alternatives to synthetic detergents are also described.