Biodegradation of the atenolol and nitrogen removal using the sequencing batch biofilm reactor

Atenolol, a widely used drug with an aromatic structure and amino groups, is one of the resistant compounds to biological degradation. In this study, the sequencing batch biofilm reactor (SBBR) was used for the biodegradation of atenolol and removing its nitrogenous compounds. Under optimal operating conditions, SBBR removed atenolol and its associated COD and total nitrogen by 93%, 87%, and 92%, respectively. SBBR has a higher ability in biodegradation, mineralization, and simultaneous removal of nitrogen compounds from atenolol than the previously studied processes. For the first time in this study, Hydrogenophaga palleronii, Corynebacterium sp., Staphylococcus hominis strain EFS, and Microbacterium paraoxydans in biofilm and Bacillus aquimaris, Hydrogenophaga palleronii, and Hydrogenophaga palleronii strain MC11 in biomass were identified as atenolol-biodegrading bacteria. Phenol, 5-methyl-2-(1-methylethyl), 2-Hexen-4-ol,5-methyl-, Docosane, Tricosane, Eicosane, (2 -ethylhexyl) phthalate, and Squalene were identified as the main intermediates resulting from the biodegradation of atenolol under optimal operating conditions by GC-MS.