废水中抗生素抗性基因（ARGs）的改变在污水处理厂（WWTP）中的研究较少，这使得难以全面评估ARGs的分散风险。因此,这项研究调查了ARGs在主要过程（厌氧-缺氧-氧化膜生物反应器（A2/OMBR）中的分布和还原，带沉降的氧化沟(OD),以及具有沉降功能的循环活性污泥系统（CASS））和全尺寸污水处理厂的消毒过程（紫外线和氯化）。在不同的主工艺和消毒工艺前后对废水进行采样;然后,ARGs和移动遗传基因的多样性和丰度(MGEs，通过实时高通量定量PCR（HT-qPCR）系统确定了不同处理阶段废水中ARGs的水平转移。发现类似的流入物会导致废水样品中类似的ARGs，独立于使用的处理过程。主要过程可以有效降低ARGs和MGE的丰度1.80-2.12和1.46-2.18对数单位，分别。影响ARGs的主要因素主要是废水水质指数,尤其是COD,和MGE如转座酶和插入序列与66和48个ARGs亚型显著相关，分别。此外，消毒在灭活抗生素耐药菌(ARB)方面比主要工艺更有效，消毒对ARB的去除率达到43.53%-100%。然而,污水处理厂废水中仍存在ARB再生(高达4.22个对数单位)的风险。在未来,营养去除和消毒工艺的改进对于去除ARG和ARB是必要的。
The alteration of antibiotic resistance genes (ARGs) in wastewater has been less studied in wastewater treatment plants (WWTPs), making it difficult to assess ARGs\' spreading risk comprehensively. Therefore, this study investigated the distribution and reduction of ARGs in the main process (Anaerobic-Anoxic-Oxic with Membrane Bio-Reactor (A2/O + MBR), Oxidation Ditch with sedimentation (OD), and Cyclic Activated Sludge System (CASS) with sedimentation) and disinfection process (Ultra-violet and Chlorination) of full-scale WWTPs. The wastewater was sampled before and after the different main process and disinfection process; then, the diversity and abundance of ARGs and mobile genetic genes (MGEs, helping the horizontal transfer of ARGs) in wastewater of different treatment stages were determined by a real-time high-throughput quantitative PCR (HT-qPCR) system. It was found that similar influents would result in similar ARGs in wastewater samples, independent of the treatment processes used. The main process could effectively reduce the abundance of ARGs and MGEs by 1.80-2.12 and 1.46-2.18 logarithm units, respectively. The main factors affecting ARGs were mainly wastewater quality index, especially COD, and MGEs like transposase and insertion sequences which were significantly associated with 66 and 48 subtypes of ARGs, respectively. Moreover, disinfection was more effective than the main process in inactivating antibiotic resistance bacteria (ARB), and the removal rate of ARB by disinfection reached 43.53 %-100 %. However, there are still risks of ARB regeneration (up to 4.22 log units) in the effluent of WWTPs. In the future, nutrient removal and disinfection process improvement is necessary to benefit ARG and ARB removal.
