东巢湖沉积物—水界面氮、磷、氧迁移特征及意义  

Characteristics and significance of nitrogen,phosphorus and oxygen transportation at the sediment water interface in east Lake Chaohu

作　　者：李运奔 匡帅 王臻宇 申秋实[2,5] 王亚东 康得军 LI Yunben;KUANG Shuai;WANG Zhenyu;SHEN Qiushi;WANG Yadong;KANG Dejun(College of Civil Engineering,Fuzhou University,Fuzhou 350116,P.R.China;State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,P.R.China;Wuhan Hanyang Municipal Construction Group Co,Ltd.,Wuhan 430050,P.R.China;Institute of Urban and Industrial Water Management,Dresden 01069,Germany;Sino Africa Joint Research Center,Chinese Academy of Sciences,Wuhan 430074,P.R.China;Jinjiang Science and Education Park of Fuzhou University,Jinjiang 362251,P.R.China)

机构地区：[1]福州大学土木工程学院,福州350116 [2]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 [3]武汉市汉阳市政建设集团有限公司,武汉430050 [4]德累斯顿工业大学城市与工业水管理研究院,德累斯顿01069 [5]中国科学院中非联合研究中心,武汉430074 [6]福州大学晋江科教园,晋江362251

出　　处：《湖泊科学》2020年第3期688-700,共13页Journal of Lake Sciences

基　　金：国家重点研发计划项目(2016YFE0123300);国家自然科学基金项目(41877488);中国科学院海外科教基地建设项目(SAJC201609);江苏省科技计划项目(BZ2018057)联合资助。

摘　　要：以东巢湖近城市湖湾沉积物为研究对象,在沉积物氮、磷营养盐分析的基础上,采用沉积物柱状芯样静态释放模拟法定量评估研究区域沉积物—水界面氨氮、溶解性活性磷酸盐营养盐释放潜力,利用微电极非损伤测定技术获得沉积物—水微界面溶解氧(DO)剖面分布及微界面DO消耗和扩散特征.结果表明:东巢湖近城市湖湾沉积物氮、磷污染物蓄积量较高,受TN、TP污染程度较重.沉积物内源氨氮、磷酸盐释放明显,平均释放速率分别达到32.44 mg/(m^2·d)和1.25mg/(m^2·d),区域内沉积物已成为水柱中氮、磷营养盐的污染源.研究区域上覆水体处于好氧状态,沉积物—水微界面平均DO穿透深度(OPD)达到5.3 mm,平均DO扩散通量为4.56 mmol/(m^2·d),表现出良好的DO扩散能力.沉积物内源氨氮和磷酸盐释放能力与表层沉积物TN/TP物质含量及沉积物—水微界面DO穿透深度有关,在沉积物氮、磷污染较重的情况下,DO穿透深度越低越有利于氮、磷污染物从沉积物向上覆水体释放.A comprehensive study of transportation features of nitrogen,phosphorous and dissolve oxygen at the sediment water in terface was carried out in near city areas of east Lake Chaohu.Based on the investigation of sediment nutrients analysis and nutri ents release incubation experiments,the release potential and release rates of ammonia nitrogen(NH3 N)and soluble reactive phosphorous(SRP)of different sediments were estimated.The distribution characteristics,diffusion fluxes,and consumption rates of dissolved oxygen(DO)at the sediment water interface of different sediments were studied by using a non invasive microelectrode analysis system.The results showed the surface sediments in the near city areas of east Lake Chaohu were in severe nitrogen and phosphorous pollution with high total nitrogen(TN)and total phosphorus(TP)loadings.Typical internal releases of NH3 N and SRP were observed from all sediments with the average release rates of 32.44 mg/(m2·d)and 1.25 mg/(m2·d),respectively.The sediments play the role of pollution source rather than the sink for NH3 N and SRP in the study area.Results also showed that all overlying water were at aerobic condition.The average oxygen penetration depth(OPD)and oxygen diffusion flux at sediment water micro interfaces reached 5.3 mm and 4.56 mmol/(m2·d)respectively,indicating good DO diffusion ability from the bounda ry layer to the sediment.The internal release intensity of NH3 N and SRP are influenced by TN/TP contents of the surface sediment as well as the OPD at the sediment water interface.The release of NH3 N and SRP from sediments could be benefited from the high nitrogen and phosphorous loadings and low OPD and contribute to the eutrophication of the lake.

关 键 词：沉积物 沉积物—水界面 营养盐 溶解氧 巢湖 

分 类 号：X524[环境科学与工程—环境工程]