School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
Ecotoxicology. 2021 Oct;30(8):1586-1597. doi: 10.1007/s10646-020-02306-0. Epub 2020 Nov 27.
Municipal wastewater treatment plants (mWWTPs), considered reservoirs of antibiotic resistance genes (ARGs), are selected to compare the contributions of technology and process to ARG removal. Fifteen ARGs (tetA, tetB, tetC, tetE, tetG, tetL, tetM, tetO, tetQ, tetS, tetX, MOX, CIT, EBC, and FOX) and two integron genes (intI1, intI2) were tracked and detected in wastewater samples from a large-scale mWWTP with four parallel processes, including three biological technologies of AAO (anaerobic-anoxic-oxic), AB (adsorption-biodegradation), and UNITANK, two different disinfection technologies, and two primary sedimentation steps. The results showed that ARGs were widely detected, among which tetA and tetM had the highest detection rate at 100%. AAO was the most effective process in removing ARGs, followed by the AB and UNITANK processes, where the separation step was critical: 37.5% AmpC β-lactamase genes were reduced by the secondary clarifier. UV disinfection was more efficient than chlorination disinfection by 47.0% in ARG removal. Both disinfection and primary sedimentation processes could effectively remove integrons, and the swirling flow grit chamber was a more effective primary settling facility in total ARG removal than the aerated grit chamber. The tet genes and AmpC β-lactamase genes were significantly correlated with the water quality indexes of BOD, COD, SS, TP, TOC, pH and NH-N (p < 0.05). In addition, the correlation between efflux pump genes and AmpC β-lactamase genes was strongly significant (r = 0.717, p < 0.01). This study provides a more powerful guide for selecting and designing treatment processes in mWWTPs with additional consideration of ARG removal.
城市污水处理厂（mWWTP）被认为是抗生素耐药基因（ARGs）的储存库，选择其来比较技术和工艺对 ARG 去除的贡献。在一个具有四个平行工艺的大型 mWWTP 的废水样本中跟踪和检测了 15 个 ARGs（tetA、tetB、tetC、tetE、tetG、tetL、tetM、tetO、tetQ、tetS、tetX、MOX、CIT、EBC 和 FOX）和两个整合子基因（intI1、intI2）。结果表明，广泛检测到 ARGs，其中 tetA 和 tetM 的检测率最高，达到 100%。AAO 是去除 ARGs 最有效的工艺，其次是 AB 和 UNITANK 工艺，其中分离步骤至关重要：二级澄清池可减少 37.5%的 AmpC β-内酰胺酶基因。UV 消毒比氯化消毒在去除 ARG 方面更有效，效率提高了 47.0%。消毒和初次沉淀过程都能有效地去除整合子，旋流沉砂池在去除总 ARG 方面比曝气沉砂池更有效。tet 基因和 AmpC β-内酰胺酶基因与 BOD、COD、SS、TP、TOC、pH 和 NH-N 等水质指标显著相关（p<0.05）。此外，外排泵基因与 AmpC β-内酰胺酶基因之间存在强显著相关性（r=0.717，p<0.01）。本研究为选择和设计 mWWTP 中的处理工艺提供了更有力的指导，同时还考虑了 ARG 的去除。
