Biodegradation of the anionic surfactant dialkyl sulphosuccinate

A range of Organisation for Economic Cooperation and Development (OECD) guideline test systems was used to determine the extent and possible mechanisms of biodegradation of dialkyl sulphosuccinate (DASS, C₆/C₈). Primary biodegradation of DASS was virtually complete in OECD guideline tests and in simulations of activated sludge sewage treatment systems under both optimal and adverse conditions, and of an anaerobic digester. Ultimate biodegradation increased from about 50% in ready tests to 94% in more powerful inherent tests. [¹⁴C]DASS was used to determine the fate of the surfactant in activated sludge and in surface waters. Mechanistic studies were performed to ascertain the biodegradative pathway of [¹⁴C]DASS. A putative degradation pathway for DASS is proposed.