Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, PR China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
Environ Sci Technol. 2023 Oct 24;57(42):16033-16042. doi: 10.1021/acs.est.3c04422. Epub 2023 Oct 12.
Halogenated organic compounds in wastewater are persistent and bioaccumulative contaminants of great concern, but few are known at the molecular level. Herein, we focus on nontarget screening of halogenated dissolved organic matter (DOM) in highly concentrated organic matrices of waste leachates and their concentrates. Solid-phase extraction (SPE) was optimized before capturing halogenated signatures via HaloSeeker 2.0 software on mining full-scan high-resolution mass spectrometry (HRMS) fingerprints. This study identified 438 Cl-/Br-containing DOM formulas in 21 leachates and membrane concentrates. Among them, 334 formulas were achieved via SPE with mixed-sorbent cartridges (mixed-SPE), surpassing the 164 formulas achieved through Bond Elut PPL cartridges (PPL-SPE). Herein, only four samples identified via PPL-SPE exhibited a resolution of >50% for extracted Cl-/Br-containing DOM by either SPE. The halogenated DOM constituted 6.87% of the total DOM mass features. Nevertheless, more abundant adsorbable organic halogens deciphered waste leachates and highly concentrated waste streams as reservoirs for halogenated contaminants. Remarkably, 75.7-98.1% of Cl-/Br-containing DOM in primary membrane concentrates remained stable through the secondary membrane treatment, indicating the persistence of these unknown contaminants even post-treatment.
废水中的卤代有机化合物是持久性和生物累积性的污染物，引起了极大的关注，但在分子水平上知之甚少。在此，我们专注于非靶向筛选废浸出液及其浓缩物中高度浓缩的有机基质中的卤代溶解性有机质（DOM）。在通过 HaloSeeker 2.0 软件对全扫描高分辨率质谱（HRMS）指纹进行挖掘之前，对固相萃取（SPE）进行了优化，以捕获卤代特征。本研究在 21 个浸出液和膜浓缩物中鉴定出 438 个含 Cl-/Br-DOM 公式。其中，通过混合吸附剂小柱（混合 SPE）实现了 334 个公式，超过了通过 Bond Elut PPL 小柱（PPL-SPE）实现的 164 个公式。在此，仅通过 PPL-SPE 鉴定的四个样品通过 SPE 对提取的含 Cl-/Br-DOM 的分辨率>50%。卤代 DOM 占总 DOM 质量特征的 6.87%。然而，更多的可吸附有机卤化物揭示了废浸出液和高浓度废水是卤代污染物的储存库。值得注意的是，在二次膜处理过程中，初级膜浓缩物中 75.7-98.1%的含 Cl-/Br-DOM 保持稳定，表明即使经过处理，这些未知污染物仍具有持久性。
