生物电化学系统强化抗生素去除过程中抗药基因的产生、分布与控制机制

Due to the poor biodegradability and high toxicity of antibiotics, antibiotics-producing wastewater cannot be effectively treated by traditional bioremediation techniques. At the same time, antibiotic resistance genes (ARGs), which has been extensively concerned as an emerging environment pollutant, should been removed before being discharged from the biological systems for antibiotics wastewater treatment. Thus, a bioelectrochemical system equipped with an electrocatalytic membrane filter will be employed for chlorinated nitroaromatic antibiotic, chloramphenicol (CAP) production wastewater treatment in this project. Firstly, the electron transfer mechanisms during the sequential reductive/oxidative bioelectrochemical degradation of CAP will be determined. Secondly, the occurrence and abundance of ARGs under various electrode potentials and antibiotic pressures will be systematically investigated. The distribution mechanism of ARGs from the aspects of horizontal gene transfer and microbial community structure will be determined. At last, an electrochemical membrane bioreactor with electrocatalytic membrane filter will be developed for enhanced treatment of CAP and CAP-resistant genes. The results will benefit more efficient removal of antibiotics and ARGs in bioelectrochemical system.

针对抗生素生产废水生化降解困难及废水处理过程中存在抗药基因污染的问题，本课题拟以生物电化学系统中氯霉素类污染物的氧化还原去除过程为研究对象，考察电势调控下，污染物与电极间的电子转移方式，分析氯霉素还原脱毒及氧化降解的协同作用机制。探索不同氧化还原条件和抗生素存在压力下微生物群落结构特征和抗药基因的类型及丰度变化，揭示抗药基因产生及分布机制。在研发新型电催化过滤膜的基础上，构建电化学膜生物反应器系统，实现抗生素、抗药基因污染物的强化去除。该课题的研究对于优化抗生素废水生物电化学处理工艺的运行及控制抗药基因的排放具有理论意义和实际价值。

抗生素的大量及其向环境的持续排放，促进了抗性细菌(ARB)和抗性基因(ARGs)的大量传播，给人类健康带来潜在危害。在污水处理系统中，抗生素仅部分被去除，并且在生化降解抗生素过程中产生的ARGs会进一步释放到环境中。本课题首先针对抗生素污染物的强化降解去除，构建了生物电化学系统来处理氯霉素废水，考察了生物电化学强化氯霉素去除的能力，同时确定了生物电化学系统中ARGs的归趋。然后基于微生物群落、整合子的丰度和ARGs的相关性分析结果确定了宿主菌变化和水平转移对ARGs变化的贡献，揭示了ARGs转移机制。最后，通过在超滤膜上修饰二氧化钛光催化材料构建光催化膜过滤系统，研究膜截留及光催化降解过程对于抗性细菌及抗性基因的去除性能和机制，并对城市污水处理工艺二级出水进行深度处理，最终实现了对抗性细菌及抗性基因的有效截留及去除。