长江重庆段主城水体沉积物溶解性有机质(DOM)的光谱特性

应用荧光发射光谱、荧光激发 发射光谱矩阵（EEMs）结合紫外 可见光吸收光谱对长江重庆段主城水体沉积物溶解性有机质(DOM)的光谱特性进行了研究。通过应用吸收指数E2/E3、荧光指数〖WTBX〗f450/f〖WTBZ〗500和三维荧光光谱特征指纹等参数，对长江重庆段主城水体沉积物溶解性有机质(DOM) 的来源、组成和空间分布规律进行了探讨。结果表明：沉积物溶解性有机质以类胡敏酸为主，其他的类富里酸、水体微生物代谢物质和类蛋白物质均有检出，陆源输入为水体沉积物溶解性有机质(DOM)主要来源，并且荧光强度在空间分布上呈现先升高后降低再升高的趋势

ASSESSING THE SPECTRA CHARACTERISTICS OF DISSOLVED ORGANIC MATTER FROM THE SEDIMENTS IN THE YANGTZE RIVER OF CHONGQING SECTION

This study used fluorescence emission spectra,fluorescence excitation-emission-matrix spectroscopy(EEMs) and UV-Vis absorbance spectra to access the spectra characteristics of dissolved organic matter(DOM) in the sediments sampled in the Yangtze River around Chongqing urban area.Absorption index E2/E3(absorbance at 250 nm to 365 nm) was observed to ensure the composition of DOM in the sediments.Meanwhile,by determining the fluorescence index f450/f500 at 370 nm with fluorescence emission spectra and analysising the EEM’s fingerprint feature,the source and spatial distribution rule of DOM were further evaluated.From the results,the value of fluorescence index f450/f500(1.42-1.63) indicated that DOM in the sediments might derive from microbial and terrestrial sources with a predominantly terrestrial origins character.The value of E2/E3 ranged from 2.02 to 3.04.Four kinds of fluorescence peaks of DOM in the sediments were identified,including a mayor component humic-like materials,other protein-like materials,fulvic materials and microbial by-products.The higher fluorescence value presented in the chonggang and cuntan sampling station,the lower fluorescence value presented in egongyan and yudong sampling station,and the fluorescence value showed the trends of up-down-up in spatial distribution along the Yangtze River of Chongqing section.