Humic-like components in dissolved organic matter inhibit cadmium sequestration by sediment  

作　　者：Bolin Li Zhongwu Li Jia Chen Changsheng Jin Weicheng Cao Bo Peng 

机构地区：[1]College of Environmental Science and Engineering,Hunan University,Key Laboratory of Environmental Biology and Pollution Control(Hunan University),Ministry of Education,Changsha 410082,China [2]Hunan Provincial Key Laboratory for Eco-environmental Changes and Carbon Sequestration of the Dongting Lake Basin,School of Geographical Sciences,Institute of Interdisciplinary Studies,Hunan Normal University,Changsha 410081,China

出　　处：《Journal of Environmental Sciences》2025年第4期645-656,共12页环境科学学报(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.42307524,and 51879103).

摘　　要：China’s lakes are plagued by cadmium(Cd)pollution.Dissolved organic matter(DOM)significantly regulates Cd(II)transport properties at the sediment-water interface.Understanding the effects of different DOM components on the transportation properties of Cd(II)at the sediment-water interface is essential.In this study,typical DOM from different sources was selected to study Cd(II)mobility at the sediment-water interface.Results showed that terrestrial-derived DOM(fulvic acids,FA)and autochthonous-derived DOM(α-amylase,B1)inhibit Cd(II)sequestration by sediments(42.5%and 5.8%,respectively),while anthropogenic-derived DOM(sodium dodecyl benzene sulfonate,SDBS)increased the Cd(II)adsorption capacity by sediments by 2.8%.Fluorescence quenching coupling with parallel factor analysis(EEM-PARAFAC)was used to characterize different DOM components.The results showed that FA contains three kinds of components(C1,C3:protein-like components,C2:humic-like components);SDBS contains two kinds of components(C1,C2:protein-like components);B1 contains three kinds of components(C1,C2:protein-like components,C3:humic-like components).Three complex reaction modelswere used to characterize the ability of Cd(II)complex with DOM,and it was found that the humic-like component could hardly be complex with Cd(II).Accordingly,humic-like components compete for Cd(II)adsorption sites on the sediment surface and inhibit Cd(II)adsorption fromsediments.Fourier transform infrared spectroscopy(FTIR)of the sediment surface before and after Cd(II)addition was analyzed and proved the competitive adsorption theory.This study provides a better understanding of the Cd(II)mobilization behavior at the sediment-water interface and indicates that the input of humic-like DOM will increase the bioavailability of Cd.

关 键 词：Dissolved organic matter Cadmium Sediments EEM-PARAFAC Adsorption 

分 类 号：O64[理学—物理化学]