Enantiomeric profiling of chiral drugs in wastewater and receiving waters

The aim of this paper is to discuss the enantiomer-specific fate of chiral drugs during wastewater treatment and in receiving waters. Several chiral drugs were studied: amphetamine-like drugs of abuse (amphetamine, methamphetamine, MDMA, MDA), ephedrines (ephedrine and pseudoephedrine), antidepressant venlafaxine, and beta-blocker atenolol. A monitoring program was undertaken in 7 WWTPs (utilizing mainly activated sludge and trickling filters technologies) and at 6 sampling points in receiving waters over the period of 9 months. The results revealed the enantiomer-specific fate of all studied drugs during both wastewater treatment and in the aqueous environment. The extent of stereoselectivity depended on several parameters including: type of chiral drug (high stereoselectivity was recorded for atenolol and MDMA), treatment technology used (activated sludge showed higher stereoselectivity than trickling filters), and season (higher stereoselectivity was observed in the aqueous environment over the spring/summer time).