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Within the scope of the study, nine waste waters from the chemical and textile industries were treated in bench-scale (laboratory scale) and small-scale (pilot scale) membrane bioreactors. Depending on wastewater characteristics, the resulting performance varied significantly. It was observed that MBR effectiveness was determined primarily by the degree of biodegradability of the wastewater. In the course of several months of operation, no significant changes associated with the complete retention of the biomass by the membranes were observed. In some cases, it was possible to improve effluent quality by using smaller molecular separation sizes. The flux performance of the membrane modules was dependent on wastewater composition. Occasionally, non-degradable macromolecular substances concentrated in the bioreactor, resulting in strongly reduced filterability and flow performance of the membrane modules, consequently also reducing the economic viability of the process. The results demonstrate that wastewater-specific pilot tests are absolutely necessary, in particular if the technology is to be used for new applications.

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). [ABSTRACT FROM AUTHOR]