湿地演替带氧化还原电位变化特征与氮素迁移转化机理

项目名称： 湿地演替带氧化还原电位变化特征与氮素迁移转化机理

项目编号： No.41272249

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 周念清

作者单位： 同济大学

项目金额： 80万元

中文摘要： 湿地在世界上广泛分布，湿地演替过程中氧化还原环境随之发生改变，而氧化还原电位（Eh）是反映氧化还原环境变化的重要指标。氮作为一种化学性质比较活跃的多价态元素，对Eh变化反映非常敏感，其存在状态、迁移和转化规律都与Eh密切相关。针对目前湖泊普遍存在的氮污染和富营养化问题，本课题拟以南洞庭湖湿地演替带为试验现场，监测Eh随土壤深度、水文要素、温度和pH的变化规律，并在Eh监测点采集水样，测定和分析氮的存在形态及特征，构建湿地演替带Eh剖面，研究Eh变化对氮赋存状态及转化的机理。同时进行室内模拟试验，测定湿地演替带土壤的渗透性，采用CT扫描研究不同土质类型中氮的迁移规律。通过对湿地演替带Eh和氮迁移转化机理的研究，探讨Eh与土壤、水文要素、氮迁移转化的关系，揭示湿地土壤和地下水中氮污染物迁移转化规律。在此基础上建立氮迁移转化数学模型，预测湿地环境时空变化趋势，对污染防治和水环境保护具有重要意义。

中文关键词： 湿地演替带；氧化还原电位；氮素；迁移转化机理；水环境

英文摘要： Wetlands are widely distributed in the world. The redox potential (Eh) is an important indicator of redox environment, which changes in the process of wetland succession. Nitrogen, as a relatively active chemical element, is sensitive to the changes of Eh, and its occurrence, migration and transformation are closely relevant to Eh. Promoted by the fact that lakes are commonly polluted by nitrogen, and lake eutrophication is very serious nowadays, we select South Dongling Lake as the test field in this subject research. The changing patterns of Eh versus soil depth, hydrological elements, temperature and pH are monitored in the field. Water samples are collected in Eh monitoring point; the occurrence and features of nitrogen are also determined and analyzed. Eh profile is constructed in wetland succession to study Eh variation with nitrogen occurrence and transformation mechanism. Simultaneously, laboratory experiments are conducted to determine the soil permeability of wetland succession. Computerized tomography (CT) is incorporated to explore the nitrogen migration law in different types of soil. By studying Eh of wetland succession and nitrogen migration and transformation mechanisms, the relationship of Eh versus soil, hydrological features, and nitrogen migration and transformation are discussed. Based on th

英文关键词： Wetland succession zone；Oxidation-reduction potential (Eh)；Nitrogen；Transport-transformation mechanism；Water environment