摘要

        合流污水溢流（CSO）通过释放CSO出水中的微生物污染物来降低水质。更好地理解微生物污染物在可沉降颗粒物上的分配，可以洞察它们在管道末端处理系统中或在CSO事件期间释放后的命运。在三次风暴事件的过程线中，以及在基流和潮湿天气期间，对受CSO影响的三个地表水进行采样。采用qPCR技术筛选抗生素耐药基因（ARG）和人类粪便指示生物（BacHum）标记基因，研究了微生物污染物在可沉降颗粒物上的分配和悬浮液中的分配。对风暴样本的两部分进行扩增子测序，以进一步确定CSO事件期间释放的微生物污染物的时间和分配。在CSO排水口采集的样本在风暴事件的早期或晚期的特定时间点显示废水的微生物群落特征。cso被发现是ARG的来源。在周围的地表水中，与基流相比，在潮湿天气期间从选定地点采集的样品中sul1含量更高。否则，ARG浓度在基流和潮湿天气条件下是可变的。CSO排水口的大部分精氨酸是在所附的样品部分上观察到的：64-79%的sul1和59-88%的tet（G）。然而，ARG和人类粪便指示剂标记基因BacHum的峰值出现时间并不一定与CSO废水中微生物特征的观察一致。因此，通过去除被测基因的附加部分，去除在整个CSO事件中运行的可沉降颗粒（例如，流体动力分离器）的单元过程将实现高达（0.5-0.9）log的ARG和粪便指标去除。如果需要进一步清除这些目标，则需要进行二次治疗。

        Combined sewer overflows (CSOs) degrade water quality through the release of microbial contaminants in CSO effluent. Improved understanding of the partitioning of microbial contaminants onto settleable particles can provide insight into their fate in end-of-pipe treatment systems or following release during CSO events. Sampling was performed across the hydrograph for three storm events as well as during baseflow and wet weather in three surface waters impacted by CSO. qPCR was performed for select antibiotic resistance genes (ARG) and a marker gene for human fecal indicator organisms (BacHum) in samples processed the partitioning of microbial contaminants on settleable particles versus suspended in the aqueous phase. Amplicon sequencing was performed on both fractions of storm samples to further define the timing and partitioning of microbial contaminants released during CSO events. Samples collected at the CSO outfall exhibited microbial community signatures of wastewater at select time points early or late in the storm events. CSOs were found to be a source of ARG. In surrounding surface waters, sul1 was higher in samples from select locations during wet weather compared to baseflow. Otherwise, ARG concentrations were variable with no differences between baseflow and wet weather conditions. The majority of ARG at the CSO outfall were observed on the attached fraction of samples: 64-79% of sul1 and 59-88% of tet(G). However, the timing of peak ARG and human fecal indicator marker gene BacHum did not necessarily coincide with observation of the microbial signature of wastewater in CSO effluent. Therefore, unit processes that remove settleable particles (e.g., hydrodynamic separators) operated throughout a CSO event would achieve up to (0.5-0.9)-log removal of ARG and fecal indicators by removing the attached fraction of measured genes. Secondary treatment would be required if greater removal of these targets is needed.

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5655003/