Spatiotemporal analysis of fluorescent dissolved organic matter to identify the impacts of failing sewer infrastructure in urban streams
Spatiotemporal analysis of fluorescent dissolved organic matter to identify the impacts of failing sewer infrastructure in urban streams
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DOI：
10.1016/j.watres.2022.119521
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发表时间：
2022-12
期刊：
影响因子：
12.8
通讯作者：
Jahir A. Batista-Andrade;Erick Diaz;Diego Iglesias Vega;Ethan Hain;Michael R. Rose;Lee Blaney
中科院分区：
文献类型：
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作者：
Jahir A. Batista-Andrade;Erick Diaz;Diego Iglesias Vega;Ethan Hain;Michael R. Rose;Lee Blaney
失败的下水道基础设施将未经处理的废水引入溪流。我们使用荧光激发-发射矩阵(EEM)光谱和平行因子分析(PARAFAC)来跟踪中低级城市溪流中的原始废水热点，这些河流不接收污水流出物，但受到卫生下水道溢出、化粪池系统和下水道渗漏的影响。通过对两个流域27个采样点1年来的2 96个地表水样品的分析，我们提出：(1)可溶微生物产物与类胡敏酸荧光的面积归一化比率(R4/R5≥0.85)和(2)类色氨酸和类黄腐酸荧光的EEM-PARAFAC组分的比率(C4/C3≥1.45)可以区分未经处理的污水何时何地进入城市河流。建议的比率通过共同检测新出现的令人担忧的污染物，如三氯蔗糖、抗生素和紫外线过滤器，浓度分别高达1354、108和212 ng L−1。根据综合数据，我们确定了农村/郊区受化粪池系统影响的三个地点和城市部分受卫生下水道溢出和/或污水渗漏影响的十个地点。此外，比值C4/C3和R4/R5参数不受降雨事件造成的稀释效应的影响。对上游站点的影响大多在春季和初夏确定，但城市热点几乎每个月都会发生。这些发现证实了基于EEM-PARAFAC的废水指示器作为一种快速、简单、成本效益高和可扩展的技术的潜力，用于筛选低级河流中出现故障的下水道基础设施。
Failing sewer infrastructure introduces raw wastewater into streams. We used fluorescence excitation-emission matrix (EEM) spectroscopy and parallel factor analysis (PARAFAC) to track hotspots of raw wastewater in low- and medium-order urban streams that do not receive wastewater effluent but are impacted by sanitary sewer overflows, septic systems, and sewer exfiltration. After analyzing 296 surface water samples from 27 sites in two watersheds over a one-year period, we proposed that the (i) area-normalized ratio of soluble microbial product-like to humic acid-like fluorescence (R4/R5 ≥ 0.85) and (ii) ratio of EEM-PARAFAC components with tryptophan-like and fulvic acid-like fluorescence (C4/C3 ≥ 1.45) could distinguish when and where untreated wastewater is introduced to urban streams. The proposed ratios were validated by co-detection of contaminants of emerging concern, such as sucralose, antibiotics, and UV filters, at concentrations as high as 1354, 108, and 212 ng L−1, respectively. Based on the aggregate data, we identified three sites in rural/suburban areas that were impacted by septic systems and ten sites in urban sections affected by sanitary sewer overflows and/or sewer exfiltration. Moreover, the ratiometric C4/C3 and R4/R5 parameters were immune to dilution effects caused by rain events. Impacts on upstream sites were mostly identified in spring and early summer, but urban hotspots occurred in almost every month. These findings confirmed the potential for EEM-PARAFAC-based wastewater indicators as a quick, easy, cost-effective, and scalable technique to screen for failing sewer infrastructure in low-order streams.