Molecular composition and chemodiversity of dissolved organic matter in wastewater sludge via Fourier transform ion cyclotron resonance mass spectrometry: Effects of extraction methods and electrospray ionization modes. (1st April 2023)

• Record Type: Journal Article
• Authors: Zhao, Peipei; Du, Zhengliang; Fu, Qinglong; Ai, Jing; Hu, Aibin; Wang, Dongsheng; Zhang, Weijun
• Is Part Of: Water research. Volume 232(2023)
• Publication Date: 2023-04-01
• Subjects: Dissolved organic matter -- Wastewater sludge -- Electrodialysis -- High-resolution mass spectrometry -- Molecular characteristics; WAS waste activated sludge -- ADS anaerobic digestion sludge -- DOC dissolved organic carbon -- DOM dissolved organic matter -- ED electrodialysis -- ESI electrospray ionization -- SPE solid phase extraction -- FT-ICR MS Fourier transform ion cyclotron resonance mass spectrometry -- 3D-EEM three-dimensional excitation-emission matrix -- EC electrical conductivity -- ESI(+) positive ESI -- ESI(−) negative ESI -- MW molecular weight -- H/C hydrogen-to-carbon molar ratio -- O/C oxygen-to-carbon molar ratio -- (DBE−O)/C double bond equivalent minus oxygen per carbon -- PCA principal component analysis -- HCA hierarchal cluster analysis -- KMD Kendrick mass defect -- ECs emerging containments -- NxO organic compounds containing x nitrogen atoms -- NOSC nominal oxidation state of carbon -- DKPs diketopiperazines -- DBP dibutyl phthalate -- DOP dioctyl terephthalate; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2023.119687
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Electrodialysis pretreatment showed high recovery efficiency for sludge-derived DOM. Molecular number in DOM identified with dual ESI modes was increased by 200%. DOMWAS mainly contained proteins/aliphatic and lipid-like compounds. DOMADS was composed of lipids, proteins/aliphatic, and lignins/CRAM-like compounds. Two ESI analysis modes can recognize different emerging contaminants. Abstract: High-resolution mass spectrometry was extensively applied in molecular composition and transformation pathways of dissolved organic matter (DOM) in wastewater sludge treatments. Sample pretreatment methods and electrospray ionization (ESI) modes significant affect the accuracy of molecular characterization for DOM. This study investigated the effects of pretreatment methods (styrene divinyl benzene polymer (PPL), octadecyl (C18), and electrodialysis (ED)) on molecular characteristics of DOM in two typical wastewater sludges (waste activated sludge (WAS) and anaerobic digestion sludge (ADS)) analyzed by FT-ICR MS in both positive ESI (ESI (+)) and negative ESI (ESI (−)) modes. The results indicated that ED pretreatment exhibited the highest recovery rate of 70% ‒ 95% for sludge-derived DOM. ED and PPL performed well in recovering the different sludge-derived DOM with a high similarity of molecular characteristics (e.g., lipids, proteins/aliphatic, and lignins/CRAM-like), and the C18 method was ineffective in extracting carbohydrates, unsaturated hydrocarbons, and amino sugars. In addition, compared with single ESI (−) analysis mode, the molecular number identified by ESI (+) analysis mode was increased by 200%, especially, more unsaturated hydrocarbons and N-containing compounds were detected. Except for biogenic DOM, plenty of emerging containments (ECs) in sludge-derived DOM were identified; ESI (−) mode was more effectively in recognizing the alkyl benzene sulfonic acids (e.g., anionic surfactants); and ESI (+) mode was more effectively for plasticizers identification, for example, dioctyl terephthalate and dibutyl phthalate. This study illustrated that ED pretreatment coupled with FT-ICR MS in dual ESI modes could give more insights in complexed molecular information for DOM in wastewater sludge, and provides a theoretical basis for subsequent sludge treatments and disposals. Graphical abstract: Image, graphical abstract