New alternatives for waste water remediation with complexing surfactants

Remediation of waste water from different sources is an important task for environmental processing. Of special technical and economic importance is the non-selective simultaneous separation of seven relevant toxic heavy metals (Hg, Cu, Cd, Cr, Ni, Zn and Pb) from waste water and industrial effluents. Reactive two-phase extraction with oil-soluble complexing surfactants could be a new technical alternative. Commercially available cation complexing surfactants are able to bind not only the six toxic heavy metals mainly present in cationic form but also Hg. Bulk metals such as Ca and Mg remain in the purified water. Waste water remediation from landfill leachates is one of the most complicated cases of application. In spite of high salt, humic acid and other organic material concentrations, the remediation results indicated great effectiveness. This method has also been applied for effluents from a zinc mine and a plating plant. In all cases the application of complexing surfactants for leachate remediation was very successful. This means that reactive liquid–liquid extraction with water-insoluble complexing surfactants may be a promising alternative environmental technology for the future.