摘要

污水处理厂（WWTPs）中细胞相关的ARGs一直是关注热点，但是污水处理厂中的游离ARGs的研究却很少。本研究以一个大型市政污水处理厂为研究对象，以sulII，tetC，blaPSE-1和ermB四种ARGs为代表，研究细胞相关的和游离的抗生素耐药基因。未处理废水中细胞相关的ARGs占主要部分。经过生物处理，污泥沉降，膜过滤和消毒后，细胞相关的ARGs大大减少，但ARG / 16S rRNA的比值在消毒后上升。污水处理过程除去游离ARG的比例为0.36 log-2.68 log，远远低于细胞相关ARG（3.21 log-4.14 log）的去除率。因此，游离ARGs与细胞相关ARGs的丰度比从0.04-1.59％上升到2.00-1895.08％。经过25天的存放，生物处理后的废水和消毒处理后的废水中的游离ARG分别增加0.14log-1.99 log和0.12 log-1.77 log，反映出排出废水中游离ARG的持续性和低衰减率。因此，游离ARGs可能是污水处理厂的一种被忽视但重要的污染物，会给污水接收环境带来了潜在的风险。

Cell-associated ARGs in wastewater treatment plants (WWTPs) has been concerned, however, cell-free ARGs in WWTPs was rarely studied. In this study, the abundances of four representative ARGs, sulII, tetC, blaPSE-1, and ermB, in a large municipal WWTP were investigated in both cell-associated and cell-free fractions. Cell-associated ARGs was the dominant ARGs fraction in the raw wastewater. After biological treatment, sludge settling, membrane filtration, and disinfection, cell-associated ARGs were substantially reduced, though the ratios of ARG/16S rRNA gene were increased with disinfection. Cell-free ARGs persisted in the WWTP with a removal of 0.36 log to 2.68 logs, which was much lower than the removal of cell-associated ARGs (3.21 logs to 4.14 logs). Therefore, the abundance ratio of cell-free ARGs to cell-associated ARGs increased from 0.04–1.59% to 2.00–1895.08% along the treatment processes. After 25-day-storage, cell-free ARGs in both biological effluent and disinfection effluent increased by 0.14 log to 1.99 logs and 0.12 log to 1.77 logs respectively, reflecting the persistence and low decay rate of cell-free ARGs in the discharge water. Therefore, cell-free ARGs might be a kind of important but previously neglected pollutant from WWTPs, which added potential risks to the effluent receiving environments.

来源http://pubs.acs.org/doi/abs/10.1021/acs.est.7b04283