title: Toward understanding the role of individual fluorescent components in DOM-metal binding.
abstract: Knowledge on the function of individual fractions in dissolved organic matter (DOM) is essential for understanding the impact of DOM on metal speciation and migration. Herein, fluorescence excitation-emission matrix quenching and parallel factor (PARAFAC) analysis were adopted for bulk DOM and chemically isolated fractions from landfill leachate, i.e., humic acids (HA), fulvic acids and hydrophilic (HyI) fraction, to elucidate the role of individual fluorescent components in metal binding (Cu(II) and Cd(II)). Three components were identified by PARAFAC model, including one humic substance (HS)-like, one protein-like and one component highly correlated with the HyI fraction. Among them, the HS-like and protein-like components were responsible for Cu(II) binding, while the protein-like component was the only fraction involved in Cd(II) complexation. It was further identified that the slight quenching effect of HA fraction by Cd(II) was induced by the presence of proteinaceous materials in HA. Fluorescent substances in the HyI fraction of landfill leachate did not play as important a role as HS did. Therefore, it was suggested that the potential risk of aged leachate (more humified) as a carrier of heavy metal should not be overlooked.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Qi-Sheng
authors.initials: QS
authors.lastname: Yao
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D002104:Cadmium / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D005163:Factor Analysis, Statistical; D005453:Fluorescence; D006812:Humic Substances; D057927:Hydrophobic and Hydrophilic Interactions; D013050:Spectrometry, Fluorescence; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001578:Benzopyrans; D006812:Humic Substances; D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper; C005023:fulvic acid