大冶水库夏秋季热分层对沉积物氮磷释放的影响  

Effect of Thermal Stratification on Nitrogen and Phosphorus Release from Sediments in Daye Reservoir

作　　者：王兴菊[1] 于文晴 赵华青 赵然杭[1] 赵莹[2] 吕静 WANG Xingju;YU Wenqing;ZHAO Huaqing;ZHAO Ranhang;ZHAO Ying;LYU Jing(Department of Civil Engineering and Water Conservancy,Shandong University,Jinan 250061,China;Water Resources Research Institute of Shandong Province,Jinan 250014,China;Jinan Water Conservancy Project Service Center,Jinan 250000,China)

机构地区：[1]山东大学土建与水利学院,山东济南250061 [2]山东省水利科学研究院,山东济南250014 [3]济南市水利工程服务中心,山东济南250000

出　　处：《环境科学与技术》2023年第10期42-52,共11页Environmental Science & Technology

基　　金：国家自然科学基金项目(51909105);济南市水务科技项目(JNSWKJ202202)。

摘　　要：水库夏秋季节的热分层现象影响水体垂向交换和水-沉积物界面环境。为研究济南市大冶水库夏秋季节热分层现象对沉积物氮磷释放的影响,作者于2022年6-10月对水库进行现场监测及采集水样、沉积物,分析水体水温和溶解氧分层特征及氮磷营养盐分布情况,并结合室内模拟实验,研究热分层导致的缺氧环境对沉积物中氮磷释放速率及迁移转化的影响。结果表明:大冶水库在6-9月热分层现象明显,10月份分层现象消失,水库表层与底层的水温差最高可达15.6℃;水体溶解氧浓度随热分层结构的形成出现垂向分层,6-8月水库底层水体出现缺氧甚至厌氧现象,7月份溶解氧浓度低至0.84 mg/L;底层水体氮磷含量显著高于表层和中层,总氮和总磷含量约为表层水体的1.5倍和4倍;溶解氧是沉积物氮磷释放的重要驱动因子,室内模拟实验表明厌氧状态下总氮和总磷的释放速率约为自然状态的1.5倍,其中沉积物氮的释放以氨氮形式为主,铁铝结合态磷是潜在磷源。大冶水库内源污染引起的水质风险不容忽视。The stratification of water temperature in the reservoir in summer and autumn has an effect on the vertical water exchange and water-sediment interface environments.In order to study the effect of stratification in summer and autumn on the release of nitrogen and phosphorus from sediments in Daye Reservoir,Jinan City,field monitoring of the reservoir was conducted,and water samples and sediments were collected from June to October 2022.The characteristics of water temperature,dissolved oxygen(DO)stratification,and the distribution of nitrogen and phosphorus nutrients were analyzed.The effects of an anoxic environment caused by thermal stratification on the release rate,migration,and transformation of nitrogen and phosphorus in sediments were studied through simulation experiments in the laboratory.The results showed that there was obvious thermal stratification in the Reservoir from June to September.In October,the stratification disappears.And the maximum water temperature difference between the surface and bottom of the reservoir is 15.6℃.The concentration of dissolved oxygen in water appears to be stratified vertically with the formation of a thermal stratification structure.From June to August,there were hypoxic and even anaerobic phenomena in the bottom water of the reservoir.In July,the concentration of dissolved oxygen was as low as 0.84 mg/L.The content of nitrogen and phosphorus in the bottom water is significantly higher than that in the surface and middle water bodies,and the content of total nitrogen(TN)and total phosphorus(TP)in the bottom water is about 1.5 times that in the surface water and 4 times that in the middle water.Dissolved oxygen is an important driver of nitrogen and phosphorus releases from sediments.The results of simulation experiments in the laboratory showed that the release rate of total nitrogen and total phosphorus in an anaerobic environment was about 1.5 times that in an aerobic environment.Nitrogen release in sediments is mainly in the form of ammonia nitrogen(NH4+-N),and F

关 键 词：热分层 溶解氧 氮磷释放 大冶水库 

分 类 号：X524[环境科学与工程—环境工程]