摘要

      饮用水源地广泛检测到抗生素耐药性，威胁饮用水源地的安全和人体健康，饮用水系统中抗生素耐药基因（ARGs）的去除值得进一步关注。在这项研究中，我们在一个饮用水处理厂（DWTP）中调查了整合酶基因intI1和41个ARG亚型的发生和减少，这些亚型对6种抗生素（β-内酰胺、氨基糖苷、大环内酯、四环素、磺胺和喹诺酮类）产生了耐药性。在原水中检测到17个ARG亚型，绝对浓度分别为1.4 × 100~7.3 ××105和3.9 ××104个基因/mL（intI1），其中sul1和sul2是两个显性ARG亚型。总体而言，与原水相比，整个DWTPs的ARGs减少了0.03-2.4log。sul1、strA和intI1的还原效率在常规工艺和高级工艺中都是最高的（1.0-2.4log）。然而，成品水中的sul1、sul2和ermC水平仍然很高（1.3×100-1.9×104个基因/mL）。预絮凝/沉降/砂滤、臭氧氧化等处理单元有利于ARGs的还原，其主要原因是生物量的下降和臭氧的强氧化性。然而，还原效果随后被颗粒活性炭和氯化装置抵消。本研究为饮用水系统中的精氨酸污染提供了基础数据，并提出精氨酸在饮用水中持续存在，即使在常规氯化或深度处理工艺之后，这突出了对新型高效净水技术的需求。

       Antibiotic resistance is extensively detected in drinking water sources, threatening its safety and human health, which deserves further attention to the removal of antibiotic resistance genes (ARGs) in the drinking water system. In this study, the occurrence and reduction of integrase gene intI1 and forty-one ARG subtypes, which confers resistance to six antibiotic classes (β-lactam, aminoglycoside, macrolide, tetracycline, sulfonamide, and quinolone), were investigated in a drinking water treatment plant (DWTP). Seventeen ARG subtypes with absolute concentrations ranging from 1.4 × 10⁰ to 7.3 × 10⁵ and 3.9 × 10⁴ genes/mL (intI1) were detected in the raw water; and sul1 and sul2 were the two dominant ARG subtypes. Overall, the whole DWTPs achieved 0.03-2.4 log reduction of ARGs compared with those presented in raw water. The reduction efficiencies of sul1, strA, and intI1 were the highest (1.0-2.4 log) in both conventional and advanced processes. However, the levels of sul1, sul2, and ermC still remained high (1.3 × 10⁰-1.9 × 10⁴ genes/mL) in finished water. The treatment units, including pre-flocculation/sedimentation/sand filtration, and ozonation units, were beneficial for the reduction of ARGs, which was mostly ascribed to the decline in biomass and the strong oxidizing properties of ozone. However, the reduction effect was subsequently counteracted by the granular activated carbon and chlorination units. This study provides basic data for ARG pollution in the drinking water system, and suggests that ARGs persist in drinking water, even after conventional chlorination or advanced treatment processes, highlighting the need for new and efficient water purification technologies.

        https://www.sciencedirect.com/science/article/pii/S0048969719311258?via%3Dihub