Study On Spectral Fingerprint Characteristics And Migration And Transformation Mechanism Of Organic Matter Of Sediments In Moguhu Reservoir

Dissolved Organic Matter(DOM)refers to the heterogeneous mixture that can pass 0.45 m pore size filter membrane,widely existing in various water bodies.DOM contains a variety of active functional groups,such as phenol hydroxyl,alcoholic hydroxyl,carbonyl,ketone,carboxyl,etc.,is the important carrier adsorption in water environment and the ligand,in the form of "DOM-pollutants" effect of heavy metal elements such as occurrence forms,migration,biological effectiveness and the final home to return to,heavy metal elements such as will directly or indirectly affect the composition,structure characteristics and spatial distribution of the DOM.Using ultraviolet-visible spectra(UV Vis)and three dimensional fluorescence spectr?m(EEMs),Fourier transform infrared spectroscopy(FTIR)to characterize upper-middle overlying water and interstitial water and sediment in the DOM of Moguhu Reservoir,identify the composition,structure,characteristics of DOM in water and the corrosion degree of qualitative,and combined with the physical and chemical properties of multivariate statistics and sediment(such as heavy metals,TN,TP)tried to expound the sediments migration into the DOM.The results showed that :(1)the DOM in the overlying water was mainly composed of fulvic acid and protein-like substances with relatively small molecules,and the degree of h ?mification was relatively low.The source was mainly endogenous,and the degree of h?mification and condensation tended to decrease gradually from the lakeside area to the deep lake area.(2)the DOM in the interstitial water mainly contains protein-like proteins with relatively small molecules,followed by fulvic acid,indicating that the microbial activity in the sediment interstitial water is strong.The source of DOM is mainly endogenous.The relative molecular weight and degree of decomposition of the DOM in the lakeside area and deep lake area are smaller than that in the shallow lake area.(3)DOM in sediments and the relative molecular mass of the h?mification degree,molecular condensation degree in the vertical distribution is: transition layer pollution > pollution layer > normal sediment layer,and the DOM in sediments are mainly composed of fulvic acid,h?mic acid,kind of protein content,functional group in the polar functional groups such as hydroxyl,carbonyl,and with the trend of nonpolar groups to polar group.(4)the relative molecular weight and degree of h?mus of DOM in sediments are affected by TN,TP and heavy metals in sediments,and DOM has homology with TN,TP and heavy metals,which affects the migration and transformation of DOM.According to the content,composition and structural characteristics of DOM in sediments,interstitial water and overlying water,as well as the correlation analysis with chemical indexes such as heavy metals,the DOM in the contaminated layer may migrate upward through interstitial water,while the DOM in the transition layer may deposit downward.