Effects of polyvinylchloride microplastics on the toxicity of nanoparticles and antibiotics to aerobic granular sludge: Nitrogen removal, microbial community and resistance genes

• Published in: Environmental research 2023-12, Vol.238, p.117151-117151, Article 117151
• Main Authors: Li, Yu-Qi, Zhao, Bai-Hang, Zhang, Yu-Qing, Zhang, Xin-Yue, Chen, Xiao-Tang, Yang, Hai-Shan
• Format: Article
• Language: English
• Subjects: Aerobic granular sludge (AGS); Antibiotics; Antibiotics resistance genes (ARGs); Microplastics; Nanoparticles
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2023.117151

Copper oxide nanoparticles (CuO NPs) and ciprofloxacin (CIP) have ecological risk to humans and ecosystems. Polyvinylchloride microplastics (PVC MPs), as a representative of microplastics, may often coexist with CuO NPs and CIP in wastewater treatment systems due to their widespread application. However, the co-impact of PVC MPs in wastewater systems contained with CuO NPs and CIP on nitrogen removal and ecological risk is not clear. In this work, PVC MPs co-impacts on the toxicity of CuO NPs and CIP to aerobic granular sludge (AGS) systems and potential mechanisms were investigated. 10 mg/L PVC MPs co-addition did not significantly affect the nitrogen removal, but it definitely changed the microbial community structure and enhanced the propagation and horizontal transfer of antibiotics resistance genes (ARGs). 100 mg/L PVC MPs co-addition resulted in a raise of CuO NP toxicity to the AGS system, but reduced the co-toxicity of CuO NPs and CIP and ARGs expression. The co-impacts with different PVC MPs concentration influenced Cu2+ concentrations, cell membrane integrity, extracellular polymeric substances (EPS) contents and microbial communities in AGS systems, and lead to a change of nitrogen removal. [Display omitted] •10 mg/L PVC MPs had no significant effect on the nitrogen removal.•100 mg/L PVC MPs decreased nitrogen removal efficiency under CuO NPs stress.•100 mg/L PVC MPs mitigated the co-toxicity of CuO NPs and CIP to AGS.•ARGs expression was enhanced by 10 mg/L PVC MPs, but decreased by 100 mg/L PVC MPs.