Development of an analytical method for the quantification of surfactants and its application to wastewater treatment plant effluents

Surfactants are a major component of many detergents and household cleansers, and therefore, they also reach surface waters to a certain extent. In order to estimate the resulting environmental risk, two surfactant groups (i.e., LAS and AES) were determined by target analysis in 33 wastewater samples from German sewage treatment plants. Additionally, several other surfactants and their degradation products were measured by non-target analysis. Despite a high removal rate in the treatment process (more than 99% for LAS and AES), average concentrations of 14.4 μg/L and 0.6 μg/L, respectively, were measured in the effluent - due to the very large amounts used. Although neither of the two target surfactants nor any of the non-target analytes has exceeded their respective limit values, effects of background level from all surfactants together cannot be excluded. Therefore, the Federal Environment Agency recommends to further monitor the occurrence of this group of compounds and recommends to reduce at least the use of LAS in the future.