Diversity of organic components in airborne waste discharged from sewer pipe repairs
Diversity of organic components in airborne waste discharged from sewer pipe repairs
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DOI：
10.1039/d3em00084b
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发表时间：
2023-09-01
影响因子：
5.5
通讯作者：
Laskin，Alexander
中科院分区：
文献类型：
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作者：
Morales，Ana C.;West，Christopher P.;Laskin，Alexander
常用的非开挖下水道管道修复技术所排放的废物是一种新兴且特征不明的城市污染源。本研究报告了在四个下水道管道维修现场收集的大气排放水相废物冷凝物样品的分子水平表征。使用反相液相色谱与光电二极管阵列检测器和配备可互换的大气压光电离和电喷雾电离源的高分辨率质谱仪研究了这些样品中有机物质的分子组成。废物冷凝物成分包含有机物质的复杂混合物，当水从空气排放的废物中蒸发时，有机物质可以在气相、水相和固相之间分配。已鉴定的有机物质在分子量、分子结构和碳氧化态方面具有广泛的可变性，废物样品之间的这些也存在差异。所有冷凝物均含有氧化有机物、含氮和含硫有机物、稠合芳烃及其官能化衍生物的复杂混合物，这些混合物在安装过程中直接释放到大气环境中。此外，半挥发性、低挥发性和极低挥发性有机化合物占废弃冷凝物中确定的总化合物的 75-85%。对特定组分粘度的估计表明，在水蒸发时，废料将形成半固相和固相。这些废弃冷凝物中化学成分的低挥发性和高粘度将有助于大气二次有机气溶胶和大气固体纳米塑料颗粒的形成。最后，对冷凝物中预期的选定成分进行了定量，发现它们以高浓度（1-20 mg L−1）存在，可能超出监管限值。
Air-discharged waste from commonly used trenchless technologies of sewer pipe repairs is an emerging and poorly characterized source of urban pollution. This study reports on the molecular-level characterization of the atmospherically discharged aqueous-phase waste condensate samples collected at four field sites of the sewer pipe repairs. The molecular composition of organic species in these samples was investigated using reversed-phase liquid chromatography coupled with a photodiode array detector and a high-resolution mass spectrometer equipped with interchangeable atmospheric pressure photoionization and electrospray ionization sources. The waste condensate components comprise a complex mixture of organic species that can partition between gas-, aqueous-, and solid-phases when water evaporates from the air-discharged waste. Identified organic species have broad variability in molecular weight, molecular structures, and carbon oxidation state, which also varied between the waste samples. All condensates contained complex mixtures of oxidized organics, N- and S-containing organics, condensed aromatics, and their functionalized derivatives that are directly released to the atmospheric environment during installations. Furthermore, semi-volatile, low volatility, and extremely low volatility organic compounds comprise 75–85% of the total compounds identified in the waste condensates. Estimates of the component-specific viscosities suggest that upon evaporation of water waste material would form the semi-solid and solid phases. The low volatilities and high viscosities of chemical components in these waste condensates will contribute to the formation of atmospheric secondary organic aerosols and atmospheric solid nanoplastic particles. Lastly, selected components expected in the condensates were quantified and found to be present at high concentrations (1–20 mg L−1) that may exceed regulatory limits.