摘要

       污水处理厂 (WWTP) 已被确定为抗生素抗性基因 (ARG) 的潜在来源，但三级污水处理工艺对 ARG 的影响尚未得到很好的表征。因此，本研究的目的是确定整个三级污水处理厂中 ARG 的归宿。两种 ARG，sul1 和 bla，通过定量聚合酶链反应 (qPCR) 在原污水、活性污泥、二级污水和三级污水的固体和溶解部分中量化。使用中试规模的介质过滤器进一步研究了三级介质过滤和氯消毒。结果表明，这两种基因在溶解部分的每个连续处理阶段都减少了。与固体相关的 ARG 在活性污泥阶段增加，并在每个后续阶段减少。总体减少量约为 4 log10，其中三级介质过滤和消毒的减少量最大。除了三级流出物中，大多数 ARG 与固体相关。没有证据表明在治疗期间对 ARG 进行了阳性选择。与未过滤的氯化二次流出物相比，通过过滤改善了氯对 ARG 的去除。这项研究表明，与单独的二级处理相比，带有消毒的三级污水处理厂可以更好地去除 ARG。

       Wastewater treatment plants (WWTPs) have been identified as potential sources of antibiotic resistance genes (ARGs) but the effects of tertiary wastewater treatment processes on ARGs have not been well characterized. Therefore, the objective of this study was to determine the fate of ARGs throughout a tertiary-stage WWTP. Two ARGs, sul1 and bla, were quantified via quantitative polymerase chain reaction (qPCR) in solids and dissolved fractions of raw sewage, activated sludge, secondary effluent and tertiary effluent from a full-scale WWTP. Tertiary media filtration and chlorine disinfection were studied further with the use of a pilot-scale media filter. Results showed that both genes were reduced at each successive stage of treatment in the dissolved fraction. The solids-associated ARGs increased during activated sludge stage and were reduced in each subsequent stage. Overall reductions were approximately four log10 with the tertiary media filtration and disinfection providing the largest decrease. The majority of ARGs were solids-associated except for in the tertiary effluent. There was no evidence for positive selection of ARGs during treatment. The removal of ARGs by chlorine was improved by filtration compared to unfiltered, chlorinated secondary effluent. This study demonstrates that tertiary-stage WWTPs with disinfection can provide superior removal of ARGs compared to secondary treatment alone. 

https://www.mdpi.com/2073-4441/10/1/37