Removal of alcohol ethoxylates, alkyl ethoxylate sulphates, and linear alkylbenzene sulphonates in wastewater treatment

Samples obtained from 6 trickling filter (TF) and 4 activated sludge (AS) treatment plants located in midwest United States, were assessed for the removal of alkyl ethoxylate sulphates (AES), alcohol ethoxylates (AE) and linear alkylbenzene sulphonates (LAS) during wastewater treatment. Samples for AE and AES analysis were collected from the influent, primary effluent and final effluent at each treatment plant hourly for 3 d. The average removal rates for AES, AE and LAS in AS treatment plants were 98, 97 and greater than 99 per cent, respectively. Lower and more variable rates were observed in TF treatment plants with average values of 83, 90 and 82 per cent, respectively. Using GRIDS modelling techniques the predicted exposure concentrations of AES, AE and LAS were below the corresponding biological predicted no-effect concentrations in greater than 98 per cent of the locations under low-flow conditions.