Sulfamethazine (SMZ) affects fermentative short-chain fatty acids production from waste activated sludge

In this study, the impact of sulfamethazine (SMZ), a typical Pharmaceuticals and Personal Care Products (PPCPs) existed in waste activated sludge (WAS), on the production of short-chain fatty acids (SCFA) during sludge anaerobic fermentation was investigated for the first time. Experimental results showed that the production of SCFA was positively affected by SMZ, which increased from 571 mg COD/L in the blank to 989 mg COD/L in the 24 mg/kg VSS SMZ reactor, causing 1.73-fold of increase. Mechanism exploration revealed that SMZ enhanced the disruption of both extracellular polymeric substances (EPS) and cell envelop, thereby benefiting the solubilization of sludge. It was also found that SMZ benefited the acidogenesis and acetogenesis processes but inhibited methonogenesis process, which was another reason for the enhanced SCFA production. Microbial analysis revealed that the abundance of anaerobic functional microorganisms in the SMZ reactor was more advantageous to acetic acid production. (C) 2018 Elsevier B.V. All rights reserved.