季节变化下黄河沉积物DOM特征及其与重金属的关系OA

[Objective]This study aims to reveal the spectral characteristics,total heavy metal concentration characteristics,and spatiotemporal distribution of dissolved organic matter(DOM)in sediments of the Henan reach of the Yellow River,and to explore the correlation between DOM and heavy metals,so as to provide a scientific basis for water resource management and ecological protection strategy formulation in the river basin.[Methods]Surface sediments collected from the Henan reach of the Yellow River in different seasons were taken as the research objects,and ultraviolet-visible absorption spectrosco-py and three-dimensional excitation-emission matrix fluorescence spectroscopy were adopted to analyze the spectral characteris-tics of DOM.Inductively coupled plasma mass spectrometry was used to determine the contents of heavy metals.Parallel fac-tor analysis and correlation analysis were applied to investigate the relationships between DOM and heavy metals across differ-ent seasons.[Results](1)The concentration of chromophoric dissolved organic matter(CDOM)was highest in autumn af-ter the water and sediment regulation project.Meanwhile,the relative contents of aromatic and hydrophobic compounds,as well as the relative molecular weight of CDOM in river sediments,increased,with an elevated proportion of allochthonous in-put.(2)Three-dimensional excitation-emission matrix fluorescence spectroscopy combined with parallel factor analysis(EEM-PARAFAC)identified two fluorescent components in summer and autumn,namely protein-like component C1 and hu-mic-like component C2.A third component,low-excitation tryptophan-like component C3,was additionally identified in win-ter.(3)CDOM in surface sediments of the Henan reach was predominantly terrigenous.The sources of CDOM in different river segments remained similar across seasons,which were mainly derived from terrestrial and soil inputs with weak autoch-thonous contribution.(4)Obvious correlations were observed for Co,Ni,Cu,and Zn and their correlation patterns varied seasonally.This indicated that anthropogenic disturbances in surrounding areas altered the characteristics and composition of CDOM in the Henan reach of the Yellow River in different seasons,leading to complex interactions between CDOM and heavy metals.[Conclusions]The findings help further clarify the migration and transformation patterns of sediment DOM and its coupling mechanism with various pollutants.This study can provide scientific data reference and theoretical support for water environment regulation and ecological restoration in the Henan reach of the Yellow River.