Removal performance and biodegradation mechanism of sulfonamides antibiotic contained wastewater by IFAS-MBR bioreactor

Sulfonamides (SAs) have been extensively detected in drinking water sources and warrant further studies on the removal of them in water treatment processes. Sulfadiazine (SDZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) were investigated using Fixed-film activated sludge membrane bioreactors (IFAS-MBRs). The research indicates that addition of SAs has obvious inhibit the removal of COD and NH4+-N in three reactors while the average removal efficiencies of SDZ, SMX and STZ were all over 94 %. The degradation mechanism of three SAs were concluded as follows: the fracture of multiple cleavage sites to form new intermediates, breaking of bonds in different R substituents to generate new substances, hydroxylation, amino nitration, and recombination between these cleavage substances. The microbial community results showed that at the phylum level, Proteobacteria was the dominant, followed by Bacteroidetes, Patescibacteria and Acidobacteria. At the genus level, Rhodanobacter may be the characteris-tic bacteria in SAs degradation.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the removal of sulfonamides in water treatment processes using fixed-film activated sludge membrane bioreactors (IFAS-MBRs). The results show that sulfonamides significantly inhibit the removal of COD and NH4+-N, but the average removal efficiencies of the tested sulfonamides are all over 94%. The study also identifies the degradation mechanisms of sulfonamides and characterizes the microbial community involved in their degradation.