Physical and chemical characteristics and nutrient release risk of sediments in Xiangjiaba Reservoir

摘要：
为了解向家坝水库沉积物碳、氮、磷营养负荷及其释放风险,采集水库不同位点的沉积物检测其理化性状,通过室内静态模拟试验评估营养盐释放风险.结果表明,沉积物以细小颗粒粉沙和黏土等为主,粉砂占比最高;pH呈中性至弱碱性;含水率较高;氧化还原电位表现为较强还原性.总氮(TN),总磷(TP)和总有机碳(TOC)的质量含量分别为(1.03±0.19)g/kg,(0.78±0.13)g/kg,(8.30±2.07)g/kg.沉积物营养盐空间分布特征总体表现为干流高于支流库湾,坝前湖泊区高于库中过渡区;垂向方向变化幅度小,无明显规律.静态模拟释放试验结果表明TN,TP释放通量分别为1.48~5.26 mg/(m·d)和1.46~2.10 mg/(m·d);空间上呈现干流TN释放通量高于支流,支流TP释放通量高于干流的特征;TOC含量处于较低水平和较低的生态风险.TN与TP的来源多样,为水库的潜在污染源.

In order to understand the carbon, nitrogen and phosphorus nutrient load and release risk of sediments in Xiangjiaba Reservoir, the physical and chemical properties of sediments at different sites of the reservoir were collected and tested, and the nutrient release risk was evaluated through static indoor simulation experiment. The results showed as follows: the sediment was mainly fine particles such as fine sand and clay, and the proportion of fine sand was the highest. The pH was neutral to slightly alkaline. The moisture content was high in the sediments. The redox potential showed strong reductibility. The contents of total nitrogen(TN), total phosphorus(TP) and total organic carbon(TOC) were(1.03±0.19) g/kg,(0.78±0.13) g/kg and(8.30±2.07) g/kg, respectively. The spatial distribution characteristics of nutrient salt were as follows: the main stream was higher than the tributary reservoir bay and the lake area in front of the dam was higher than the transition area in the reservoir. The vertical direction change amplitude is small and there is no obvious rule. The static simulated release experiment results showed that TN and TP release fluxes were 1.48-5.26 mg/(m~2·d) and 1.46-2.10 mg/(m~2·d), respectively. The TN release flux of the main stream is higher than that of the tributary, and the TP release flux of the tributary is higher than that of the main stream. The results showed that the TOC content was at a low level with a low ecological risk. The sources of TN and TP are diverse. Nitrogen and phosphorus are potential pollution sources of reservoirs, which deserve attention and attention.

作者：
米武娟 张地继 许元钊 孙志峰 张春光 刘芳枝 毕永红

Mi Wujuan;Zhang Diji;Xu Yuanzhao;Sun Zhifeng;Zhang Chunguang;Liu Fangzhi;Bi Yonghong(State Key Laboratory of Fresh Water Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;River Basin Comples Administration Centre,China Three Gorges Corporation,Yichang 443000,China)

机构地区：
中国科学院淡水生态与生物技术国家重点实验室 中国长江三峡集团有限公司流域枢纽运行管理中心

出处：
《betway官方app 学报：自然科学版》 CAS 北大核心 2022年第5期117-123,I0003,I0004,共9页

Journal of Henan Normal University(Natural Science Edition)

基金：
国家自然科学基金(31971477) 中国长江三峡集团有限公司2019年向家坝水库水华监测项目(SXSN/4495).

关键词：
向家坝水库 沉积物 理化性质 营养盐释放

Xiangjiaba Reservoir sediment physical and chemical properties nutrient release

分类号：
X524 [环境科学与工程—环境工程]

向家坝水库沉积物理化特性及其营养释放风险.pdf