我国富营养化湖泊小分子有机酸环境地球化学特征与环境效应

Low-molecular weight organic acids (LMWOAs) represent the intermediate degradation products of macromolecular weight organic matter, serve important functions in ecological environment of lake. In this research proposal, three eutrophic shallow lakes situated in Yunan-Guizhou Plateau and Middle-Lower Yangtze Plain are selected, e.g. Dianchi, Taihu and Chaohu Lake. According to their different elevations and geographic features, ion chromatography is used to detect contents and identify variety of LMWOAs, revealing their seasonal and profile distribution patterns. Combining with analysis of DOC, it is expounded that LMWOAs play an important role during organic matter transformation and early diagenesis in sediments. Through detection of basic hydrochemical parameters, the function of LMWOAs as indicators to water quality evolution is also interpreted. The composition, distribution and humification of organic matter are characterized and biological parameters are analyzed, suggesting the source/ sink transformation mechanisms and main influencing factors of LMWOAs. Gas chromatography is used to detect the desorption amount of pollutants adherent to sediments (e.g. phenanthrene and pyrene), revealing the influencing extent of LMWOAs on allocation of pollutants in different phases and their adsorption-release process. This research will systematically clarify how environmental effects are caused by LMWOAs behaviors and related mechanisms, also deepen our understanding on decomposition and transformation of organic matter, construct theoretical basis for ecological risk assessment of lakes, conducive to more control over polluted lakes and their proper management.

小分子有机酸是大分子有机质降解的中间产物，在湖泊生态环境中起到了重要作用。本申请主要选取云贵高原及平原几个富营养化浅水湖泊滇池、太湖、巢湖，针对它们不同海拔及地理特征，运用离子色谱技术辨识有机酸的种类及含量，揭示有机酸的季节、剖面变化规律，结合DOC的检测分析，阐明有机酸在有机质转化及沉积物早期成岩过程中的作用；基本水化学参数的检测，阐述有机酸在湖泊水质演化历程中的指示作用；通过有机质组成、分布及腐殖化程度的表征及生物学分析，揭示有机酸的源/汇机制及其主要影响因素；利用气相色谱技术检测沉积物污染物(菲、芘)的解吸量，揭示有机酸对污染物在不同相态间分配及其吸附-释放过程的影响程度。系统阐明有机酸行为过程中的环境效应机制，加深对有机质分解转化过程的认识，为湖泊生态风险评估提供理论基础，有利于加强对湖泊环境污染的控制及妥善管理。

小分子有机酸是大分子有机质降解的中间产物，在湖泊生态环境中起到了重要作用。本研究主要选择云南浅水湖泊滇池作为研究对象，根据其海拔及地理特征，运用离子色谱技术辨识有机酸的种类及含量，揭示有机酸的季节、剖面变化规律，结合DOC的检测分析，阐明有机酸在有机质转化及沉积物早期成岩过程中的作用；基本水化学参数的检测，阐述有机酸在湖泊水质演化历程中的指示作用；通过有机质组成、分布及腐殖化程度的表征及生物学分析，揭示有机酸的源/汇机制及其主要影响因素；利用电感耦合等离子质谱仪检测微量金属元素如Cu、Cd、Zn、Fe、Al等，揭示有机质在迁移转化过程中对金属元素的影响。系统阐明有机酸行为过程中的环境效应机制，加深对有机质分解转化过程的认识，为湖泊生态风险评估提供理论基础，有利于加强对湖泊环境污染的控制及妥善管理。