丰水期渤海湾水体中DOM的分布特征及来源

为了解丰水期渤海湾水体中污染物的来源，采用三维荧光光谱和紫外光谱，结合平行分子模型和相关性分析研究了渤海湾水体中DOM（溶解性有机质）的分布特征和来源，以期间接了解其他污染物的来源.结果表明：渤海湾水体DOM对荧光强度贡献率表现为近岸海域高，而远离海岸的海域低.DOM荧光光谱主要有高激发光色氨酸（S峰）、低激发光色氨酸（T峰）、类腐殖酸（A峰）和类富里酸（C峰）这四类荧光峰，类蛋白类荧光峰（S峰和T峰）在研究海域北部荧光强度贡献率较高，类腐殖质类（A峰和C峰）呈现近海岸高、远离海岸低的特征；渤海湾和入海河流荧光指数（FI）均在1.4左右，说明类腐殖质主要受到外源影响，大部分显示出强腐殖质化特征（HIX >3.0），只有子研究区北部区域由于藻类暴发显示出强自生源特征（BIX >1.0）.紫外特征吸收波长结果显示渤海湾近岸海域类富里酸和类腐殖酸对紫外吸收系数的贡献率（20.18±4.04）%显著低于入海河流中的类富里酸和类腐殖酸贡献率（26.43±3.85）%，可能是由于入海河流输入DOM受到了海水盐度作用，高盐度海水会使DOM产生絮凝作用，随着悬浮物汇入海底沉积物中，使DOM中类富里酸和类腐殖酸对紫外吸收系数的贡献率降低.整体上渤海湾水体中DOM在丰水期受到外源河流输入影响较为显著，应加强对外源输入河流污染物的控制和管理.

Distribution characteristics and sources of DOM in Bohai Bay seawater during wet season

The distribution characteristics and sources of dissolved organic matter (DOM) in Bohai Bay water were studied by using three-dimensional fluorescence and ultraviolet spectrum, combined with the parallel molecular model and correlation analysis in order to indirectly understand the sources of other pollutants. The results showed that the DOM content in Bohai Bay water was high in the offshore water, but low away from the coast. The main components were high excitation tryptophan (S peak), low excitation tryptophan (T peak), humic acid (A peak) and fulvic acid (C peak). The protein-like fluorescence peak has a high intensity in the northern part of the study area, and the humus-like peak had a low intensity far away from the coast. Fluorescence indices (FI) of the Bohai Bay and the river into the sea were all about 1.4, indicating that the humus were mainly affected by exogenous sources, and most of them showed strong humic characteristics (HIX >3.0), only the northern part of the study area showed strong autogenetic characteristics due to algae outbreaks (BIX >1.0). Because of the influence of salinity, the UV characteristic absorption wavelength showed that the percentages of fulvic and humic acids (20.18±4.04)% in the coastal water of Bohai Bay were significantly lower than those of the exogenous river (26.43±3.85)%. Seawater with high salinity will cause flocculation of DOM, and the proportion of Fulicid-like acids and Humicid-like acids in DOM will decrease as the suspended solids are absorbed into the seabed sediments. As a whole, DOM in Bohai Bay was significantly affected by exogenous river input in wet season, so it is necessary to strengthen the control and management of exogenous river input pollutants.