Removal of anionic and nonionic surfactants in a wastewater treatment plant with anaerobic digestion. A comparative study

This paper presents a comparative study of the elimination of anionic surfactants (linear alkylbenzene sulphonates, LAS) and nonionic surfactants in a conventional municipal activated sludge plant. The LAS were analysed by high performance liquid chromatography, after extraction and purification. The nonionic surfactants was analysed by the Wickbold method. The elimination of the surfactants in water, suspended solids and sludges were determined in the different stages of the purification process. The results obtained show that over 90% of the surfactants were eliminated. The maximum degradation took place in the aeration tank.