Characterization of mercury binding to different molecular weight fractions of dissolved organic matter

• Published in: Journal of hazardous materials Vol. 431; p. 128593
• Main Authors: Cui, Hongyang, Zhao, Yue, Zhao, Li, Wei, Zimin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.06.2022
• Subjects: 2,5-Dimethoxy-4-Methylamphetamine; Contaminate control; Dissolved Organic Matter; Dissolved organic matter (DOM); Humic Substances - analysis; Ligands; Mercury; Molecular Weight; Parallel factor analysis (PARAFAC); Spectrometry, Fluorescence - methods; Ultrafiltration fraction; Dissolved organic matter (DOM); Ultrafiltration fraction; Contaminate control; Mercury; Parallel factor analysis (PARAFAC)
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.128593

Dissolved organic matter (DOM) can strongly complex with various contaminants. Therefore, DOM was deemed as an environmentally friendly substance for controlling the mobility, bioavailability, speciation, toxicity, and fate of metal contaminants in environment. In this study, composting-derived DOM was categorized into three fractions based on different molecular weights (MWs). Furthermore, parallel faction analysis (PARAFAC), two-dimensional correlation spectroscopy (2DCOS), and a complexation model were employed to reveal the contaminate-binding characterization. Two PARAFAC fluorescence components were identified in the MW < 1 kDa and the 1 kDa < MW < 5 kDa fractions, respectively. In the MW > 5 kDa fraction, three PARAFAC components were identified. Protein-like component C5 did not have the Hg2+-binding ability. Moreover, the results showed that not all the DOM ligands could bind with contaminants, but a high humification degree of composting DOM ligands could strongly bind Hg2+. In addition, DOM ligand with a low humification degree DOM ligands presented a higher Hg2+-binding speed. Subsequently, DOM from different MWs DOM could be applied separately to the different pollution forms. With these promising results, the different DOM ligand-Hg2+-binding properties were characterized to provide theoretical support for environmental pollution control. [Display omitted] •PARAFAC-2DCOS can characterize the contaminant-DOM ligands.•The Hg2+-binding properties of different molecular weight DOM ligands were assessed.•High humification degree of DOM ligands presented strong Hg2+-binding capacity.•DOM-Hg2+-binding properties offered theoretical supporting of pollution control.