Enantioselective degradation of amphetamine-like environmental micropollutants (amphetamine, methamphetamine, MDMA and MDA) in urban water
Environmental Pollution May 13, 2016 Siân E. Evans, John Bagnall, Barbara Kasprzyk‐hordern 50 citations
Amphetamine-like compounds undergo stereoselective degradation during wastewater treatment and in receiving waters, with microbial processes favoring the S-(+)-enantiomer over the R-(-)-enantiomer. In controlled laboratory microcosms simulating activated sludge, all four compounds—amphetamine, methamphetamine, MDMA, and MDA—showed preferential breakdown of the S-(+)-enantiomer, while R-(-)-enantiomers remained largely undegraded, indicating greater persistence. Amphetamine was the most biodegradable, followed by MDMA and methamphetamine. Photochemical processes degraded MDMA and methamphetamine but were not stereoselective. Biodegradation of S-(+)-methamphetamine produced S-(+)-amphetamine, and racemic MDMA degraded stereoselectively in activated sludge, enriching R-(-)-MDMA and forming S-(+)-MDA. Only mild stereoselectivity occurred during MDMA degradation in river water, likely due to different microbial communities. Kinetic studies confirmed MDMA's recalcitrance.