Performance and responses of aerobic granular sludge at different concentrations of graphene oxide after a single administered dose.

Abstract

To investigate the impact of graphene oxide (GO) under different concentrations (0, 50, 100, 150, 200 mg/L) on aerobic granular sludge (AGS) after a single administered dose, the performance of nitrogen removal, microbial enzymatic activity, extracellular polymeric substances (EPS), and microbial community structure were analysed in batch tests. The results showed that the impact of GO concentrations on AGS was dose and time dependent. Short-term GO exposure could accelerate the nitrification process of AGS, while relatively concentrations (≥100 mg/L) inhibited the process when present for extended periods of time. The microbial enzymatic activity showed similar tendency. The production of lactate dehydrogenase release (LDH) in 200 mg/L group was increased 48.04% and EPS contents decreased 30.06% compared to the control group at 30th day, showed that high concentrations of GO have toxic effects on AGS. The microbial bacteria responded differently to the stimulation of different concentrations of GO.