Effects of antibiotics on enhanced biological phosphorus removal and its mechanisms

• Published in: The Science of the total environment Vol. 774; p. 145571
• Main Authors: Wu, Ligui, Wei, Quantao, Zhang, Yingying, Fan, Yuxing, Li, Mi, Rong, Lingling, Xiao, Xiaoyu, Huang, Xiangfeng, Zou, Xiaoming
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20-06-2021
• Subjects: Anti-Bacterial Agents - toxicity; Antibiotics; Bioreactors; Enhanced biological phosphorus removal; Mechanisms; Molecular docking; Molecular Docking Simulation; Phosphorus; Sewage; Toxicity; Waste Disposal, Fluid; SBR; Mechanisms; ESP; WWTPs; Toxicity; PHA; ADK; PPK; DO; Ep; Molecular docking; PAOs; SRT; Antibiotics; SOP; PPX; Enhanced biological phosphorus removal; EBPR
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.145571

Many kinds of antibiotics are continuously discharged into wastewater and typically cause a great decrease in sewage treatment performance, whereas mechanisms of differences in the impacts of commonly used antibiotics on phosphate removal are still elusive. Thus, an enhanced biological phosphorus removal (EBPR) system, as an effective method of phosphate removal, was developed, and its performance in the treatment of artificial wastewater containing antibiotics at short- (8 h) and long-term (15 days) exposure was investigated. The results show that phosphorus removal was consistently inhibited by the addition of antibiotics with a significant difference (P < 0.05). To interpret the phenomena, mechanistic equations were developed, and the results indicate that for short-term tests, the difference was mainly caused by the suppression of polyhydroxyalkanoate (PHA) degradation and the activity of polyphosphate kinase (PPK), resulting in the different inhibition of the soluble orthophosphorus (SOP) uptake process. For long-term tests, the difference in SOP uptake was principally caused by the inhibition of PHA degradation and the activity of PPK, whereas the difference in SOP release resulted from the inhibition of activities of exopolyphosphatase (PPX) and adenylate kinase (ADK). Moreover, micro-mechanisms of such inhibition were identified from molecular docking and electrostatic potential.
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•Ten antibiotics on SOP removal through an EBPR system significantly differ.•The difference in short-term tests was caused by inhibition of SOP uptake.•The difference in long-term tests was caused by SOP release and uptake inhibition.•The inhibition of PHA degradation and enzymes caused the SOP removal decreased.•Inhibition of enzymes was related to interaction between antibiotic and receptor.