Xu Yifeng, Gu Ying, Peng Lai, Wang Ning, Chen Shi, Liang Chuanzhou, Liu Yiwen, Ni Bing-Jie
Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, China; Shenzhen Research Institute of Wuhan University of Technology, Shenzhen, 518000, Guangdong, China.
Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, China.
Chemosphere. 2023 Apr;320:138099. doi: 10.1016/j.chemosphere.2023.138099. Epub 2023 Feb 8.
Although moving bed biofilm reactors (MBBRs) have shown excellent antibiotic removal potentials, the information on underlying mechanisms is yet limited. This work assessed the removal of ciprofloxacin in an enriched nitrifying MBBR by clarifying the contribution of adsorption and microbial-induced biodegradation. Results demonstrated the considerable biomass adsorption (55%) in first 30 min. Limiting nitrite oxidizing bacteria growth or inhibiting nitrification would lead to lower adsorption capacities. The highest ciprofloxacin biodegradation rate constant was 0.082 L g SS h in the presence of ammonium, owing to ammonia oxidizing bacteria (AOB)-induced cometabolism, while heterotrophs played an insignificant role (∼9%) in ciprofloxacin biodegradation. The developed model also suggested the importance of AOB-induced cometabolism and metabolism over heterotrophs-induced biodegradation by analyzing the respective biodegradation coefficients. Cometabolic biodegradation pathways of ciprofloxacin mainly involved the piperazine ring cleavage, probably alleviating antimicrobial activities. It implies the feasibility of nitrifying biofilm systems towards efficient antibiotic removal from wastewater.
尽管移动床生物膜反应器（MBBRs）已显示出卓越的抗生素去除潜力，但关于其潜在机制的信息仍然有限。这项工作通过阐明吸附和微生物诱导的生物降解的贡献，评估了富集硝化MBBR中对环丙沙星的去除情况。结果表明，在前30分钟内存在大量生物质吸附（55%）。限制亚硝酸盐氧化细菌的生长或抑制硝化作用会导致吸附容量降低。在铵存在的情况下，环丙沙星的最高生物降解速率常数为0.082 L g SS h，这归因于氨氧化细菌（AOB）诱导的共代谢作用，而异养菌在环丙沙星生物降解中起的作用微不足道（约9%）。通过分析各自的生物降解系数，所建立的模型还表明了AOB诱导的共代谢作用和代谢作用相对于异养菌诱导的生物降解的重要性。环丙沙星的共代谢生物降解途径主要涉及哌嗪环的裂解，这可能减轻了抗菌活性。这意味着硝化生物膜系统从废水中高效去除抗生素的可行性。
