Effects of sulfamethoxazole on aerobic sludge granulation process.

Abstract

Our purpose was to clarify the effect of sulfamethoxazole (SMX) on the start-up period, particle formation, and treatment efficiency of an aerobic granular sludge system. We compared an R1granular sequencing batch reactor (GSBR) started with 5μgL-1 SMX and an R2 GSBR started without SMX, as a control, to investigate the impact of a trace amount of SMX (5μgL-1 ) on aerobic granular sludge (AGS) characteristics and the removal of conventional contaminants. AGS granulation in the R1system was not inhibited by SMX, but the granule particle size was smaller than that in the R2system. Both systems had good performance removing conventional pollutants. Extracellular polymeric substance secretion in the R1system was lower than that in the R2system. After stabilizing reactor operations, the SMX removal efficiency in the R1system (~73.93%) was higher than that in the R2system (~70.66%). The start-up modes also determined the differences in the microbial community structure of the AGS systems. SMX-activated AGS performed better than AGS without SMX. The study can help engineers determine start-up modes with varieties of antibiotics in AGS processes and provide references for the optimization of water treatment processes.