Removals of atenolol, gliclazide and prazosin using sequencing batch reactor

Abstract

Emergence of organic micropollutants, specifically pharmaceutical compounds (PhCs) in receiving water bodies possess a great threat towards our ecosystem presently and in future. By that, evaluating and monitoring the removal of PhCs, specifically those highly consumed in a certain area, is considerably critical in attempt to minimize discharge of PhCs in our waters. Therefore, this study assessed the removal mechanisms of three highly consumed PhCs in Malaysia, namely atenolol, gliclazide and prazosin, by considering the hydrolysis, adsorption and biodegradation mechanisms of the selected compounds. Moreover, the removal of these compounds was demonstrated in an aerobic sequencing batch reactor (SBR) system treating actual domestic wastewater added with the selected compounds. The detection of PhCs was conducted using using Ultra-High Performance Liquid Chromatography Quadrupole-Time-Of-Flight Mass Spectrometry (UHPLC/QTOF-MS), followed by investigation of microbial community in the sludge sample by next generation sequencing (NGS). The results highlighted that atenolol was highly biodegradable with 83% efficiency in SBR system. Meanwhile, both gliclazide and prazosin show moderate biodegradation efficiency at 41%. The results also demonstrated that gliclazide and prazosin exhibited recalcitrant behavior towards the biological treatment. In addition, prazosin was presumed to be hydrolyzed and exist as different chemical structure in the aqueous phase during treatment process. The microbial community analysis revealed Mycobacterium as one of the potential microbes in biodegradation of PhCs.