• 关键词：网湖  沉积物  内源释放  静态释放  再悬浮

• 基金项目：中央级公益性科研院所基本科研业务专项（No.PM-zx703-202002-025）；国家自然科学基金项目（No.21707040）

• 荣楠
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 周道坤
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 郭灿斌
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 王文静
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 朱家亮
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 陈中颖
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 卢文洲
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 刘晓伟
• 生态环境部华南环境科学研究所，广州 510530;国家水环境模拟与污染控制重点实验室，广州 510530;广东省水与大气重点实验室，广州 510530

• 摘要：网湖位于长江中游，富营养化问题突出，然而目前缺少对网湖内源氮、磷污染负荷的系统研究.通过采集原位柱状沉积物样品，分析了网湖沉积物氮、磷赋存量及空间分布特征.以野外再悬浮观测和室内静态培养相结合的方式，分析了底泥氮磷静态释放通量和再悬浮释放通量.结果表明：底泥TN、TP含量分别为1580~4530 mg·kg^-1（平均值3122 mg·kg^-1）和45~2106 mg·kg^-1（平均值913 mg·kg^-1），氮、磷累积污染量大.西北部湖湾I区表层沉积物TN含量最高，与该区接纳的来自于赛桥湖的污染物入湖通量最大有关.TP含量最高点位于湖心IV区，主要受历史投肥养殖造成的底泥磷累积污染影响.PO₄^3-的静态释放通量为7.4~50.9 mg·m^-2·d^-1，平均值为18.7 mg·m^-2·d^-1，沉积物能持续向上覆水释放PO₄^3-.静态释放模式下，沉积物既表现为TN和TP的“源”，又表现为二者的“汇”.仅考虑底泥的静态释放模式，网湖TN、TP、PO₄^3-的总释放量分别为584、11.4和167.2 t·a^-1.综合考虑静态释放和动力扰动，估算网湖内源年释放量分别为TN 1195.8 t、TP 253.5 t、PO₄^3- 216.1 t.西北部湖区接纳的氮、磷污染通量最大，湖心区是主要的投肥养殖区域，这两个区域的沉积物氮、磷污染负荷尤为突出，应成为网湖内源污染整治的关键区域.

• Abstract：The Wanghu Lake is located in the middle reaches of the Yangtze River， and the problem of eutrophication is prominent. However， detailed research on the internal loadings of nitrogen and phosphorus is still limited. In this study， a series of in situ sediment core samples were collected to analyze loads and spatial distribution characteristics of nitrogen and phosphorus in the sediment. Field observation of sediment re-suspension and laboratory incubation were carried out to investigate the static and suspended release fluxes of nitrogen and phosphorus in the sediment. Results showed that the contents of total nitrogen and total phosphorus in sediments were in the range of 1580~4530 mg·kg^-1 （mean： 3122 mg·kg^-1） and 45~2106 mg·kg^-1 （mean： 913 mg·kg^-1）， respectively. This indicated that a large quantity of nitrogen and phosphorus were accumulated in the sediment. The content of total nitrogen in surface sediments from area I in the northwest of the lake was the highest due to the largest pollutant flux from the Saiqiao Lake to the Wanghu Lake. The highest total phosphorus content was located in area IV in the middle of the lake， which was mainly affected by phosphorus accumulation pollution caused by fertilization of aquaculture. The static release fluxes of PO₄^3- were in the range of 7.4~50.9 mg·m^-2·d^-1， with mean value of 18.7 mg·m^-2·d^-1. The result indicated that PO₄^3- can be continuously released from the sediment to the overlying water. In the static release process， the sediment acted as both ‘source’ and ‘sink’ of total nitrogen and total phosphorus. The total static release amount of total nitrogen， total phosphorus and PO₄^3- were 584， 11.4 t·a^-1 and 167.2 t·a^-1， respectively. Considering static release and dynamic disturbance， the annual endogenous release of total nitrogen， total phosphorus and PO₄^3- were estimated to be 1195.8 ， 253.5 and 216.1 t. The largest input fluxes of nitrogen and phosphorus were found in the northwest of the Wanghu Lake. The central area of the Wanghu Lake was the main area of fertilization for aquaculture. The nitrogen and phosphorus loads in sediments from these two areas were particularly high ， which could be the key areas to control the internal pollution of the Wanghu Lake.

• Key words：the Wanghu Lake  sediment  endogenous release  static release  resuspension

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