A literature review of environmental properties of surfactants is given. The fate of surfactants in sewage systems was investigated, i.e. the anaerobe biodegradability, bioaccumulation and toxicity towards aquatic and sediment-living organisms.
An essential output of the project was that for the surfactants investigated the effect concentrations from long-term and short-term toxicity studies were comparable. This indicates that, for easily metabolized surfactants, a potential for bioaccumulation (high log Kow) does not necessarily lead to a higher long-term toxicity as it is usually expected.
Furthermore, it was demonstrated that discharge of the detergents LAS and NP from Norwegian WWTPs with only chemical treatment may lead to risk quotients above 1 both in water phase and in the sediments. For WWTPs with biological treatment, the risk quotients for NP were still above 1 whereas the risk quotients for LAS were well below 1.
Based on the performed investigation, it seems that, as a minimum, biological treatment is needed for removal of detergents as LAS and NP.