摘要
      表面活性剂可以影响污泥形态，消毒剂与抗生素抗性基因（ARGs）有关。因此，活性污泥和ARGs对长期暴露于季铵化合物（QACs）的反应需要进一步研究，这是一种流行的表面活性剂和消毒剂。在这里，三个序批式反应器中加入5 mg/L最常检测到的QACs（十二烷基三甲基氯化铵（ATMAC C12）、十二烷基苄基二甲基氯化铵）（BAC C12）和二十二烷基二甲基氯化胺（DADMAC C12））180 d。对脱氮的长期抑制作用排名为：DADMAC C11>BAC C12>ATMAC C12。此外，在DADMAC C12系统中，由于α-螺旋/（β-片+随机线圈）的增加，出现了明显的颗粒污泥。此外，当反硝化系统急性遇到QACs时，细胞内ARG增加，但在长期暴露于QACs的系统中减少。尽管ATMAC C12系统中的复制和修复代谢更高，但ATMACC12显著促进了细胞外ARGs的增殖。值得注意的是，在污泥颗粒化过程中，细胞外ARGs在污泥中的传播风险显著增加，并且在DADMAC C12系统中，污泥和水中的细胞内sul2基因都随着颗粒直径的增加而增加。QACs的普遍使用可能会增强污水处理厂细菌的抗生素耐药性，值得更多关注。
Abstract
Surfactants could influence sludge morphology and disinfectants were linked to antibiotic resistance genes (ARGs). Thus, the response of activated sludge and ARGs to long-term quaternary ammonium compounds (QACs) exposure required further investigation, which is a popular surfactant and disinfectant. Here, three sequencing batch reactors were fed with 5 mg/L most frequently detected QACs (dodecyl trimethyl ammonium chloride (ATMAC C12), dodecyl benzyl dimethyl ammonium chloride (BAC C12) and didodecyl dimethyl ammonium chloride (DADMAC C12)) for 180 d. The long-term inhibitory effect on denitrification ranked: DADMAC C12 > BAC C12 > ATMAC C12. Besides, obvious granular sludge promoted by the increase of α-Helix/(β-Sheet + Random coil) appeared in DADMAC C12 system. Moreover, intracellular ARGs increased when denitrification systems encountered QACs acutely but decreased in systems chronically exposed to QACs. Although replication and repair metabolism in ATMAC C12 system was higher, ATMAC C12 significantly promoted proliferation of extracellular ARGs. It was noteworthy that the propagation risk of extracellular ARGs in sludge increased significantly during sludge granulation process, and intracellular sul2 genes in sludge and water both increased with the granular diameter in DADMAC C12 system. The universal utilization of QACs may enhance antibiotic resistance of bacteria in wastewater treatment plants, deserving more attention.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422022580