Evaluation of advanced treatment technologies for the elimination of pharmaceutical compounds

Pharmaceuticals and their metabolites have developed as ecotoxicologically relevant micropollutants in the aquatic environment. During conventional biological wastewater treatment they are eliminated insufficiently and therefore reach surface waters via discharges. They are either partially or completely non-biodegradable and/or hardly eliminable by activated sludge adsorption because they often have polar structures. Membrane bioreactor treatment (MBR) was applied to pre-treat wastewater containing pharmaceutical compounds, e.g., antibiotics like floxacins and their synthetic precursor compounds. Our objectives were to eliminate these persistent target compounds from wastewater prior to discharge into receiving waters. Therefore an advanced treatment applying MBR combined with different chemical and physicochemical processes was performed. The addition of powdered activated carbon (PAC), nano filtration (NF), reverse osmosis (UO) or ozone (O₃) and O₃/UV were applied to MBR permeate spiked with the selected target compounds. Treatment efficiency was assessed using conventional inorganic and organic chemical analyses besides advanced physicochemical methods like liquid chromatography coupled with mass and tandem mass spectrometry (LC-MS and –MS-MS).