| 引用本文: | 赵政,钱姝羽,白雷雷,王春柳,江和龙.新型通江湖泊滆湖沉积物内源污染物分布及释放特征.湖泊科学,2025,37(3):872-888. DOI:10.18307/2025.0325 |
| Zhao Zheng,Qian Shuyu,Bai Leilei,Wang Chunliu,Jiang Helong.Distribution and release characteristics of endogenous pollutants in sediment of Lake Gehu, a new river-connected lake. J. Lake Sci.2025,37(3):872-888. DOI:10.18307/2025.0325 |
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| 摘要: |
| 滆湖作为新型通江湖泊，是太湖流域湖西地区重要的行蓄洪湖泊和新孟河引江济太的重要通道，滆湖治理是新一轮太湖治理的重要内容。为探究滆湖水体和沉积物中氮、磷污染状况以及沉积物内源污染释放风险，在全湖设置13个采样点位进行调查，并通过静态释放培养法模拟实验分析沉积物氮、磷的释放规律和释放效应。结果表明：（1）滆湖水体的总氮（(1.43±0.27) mg/L）和总磷（(0.12±0.06) mg/L）浓度处于Ⅳ类水范围内，开发利用程度较大的北部湖区污染较重，空间上由北向南污染降低；（2）现阶段沉积物总氮（(1.38±0.44) mg/g）和总磷（(0.34±0.07) mg/g）的综合评价指标显示，全湖沉积物氮、磷整体处于轻度污染水平，污染区域主要集中在北部滆湖旅游点附近、湖心区以及靠近太滆运河、漕桥河和殷村港的出湖河口区域，泥沙在该区域可能有淤积，表层沉积物更疏松、偏软，抗剪切能力小，泥沙输移和内源释放潜力较大；（3）沉积物存在内源氮磷释放的风险，释放效应集中在前48 h，沉积物中的氮主要影响上覆水中硝态氮的浓度，磷存在正磷酸盐的释放和颗粒态有机磷的解吸附，湖心处和南部湖区是内源污染的重要区域。因此，在滆湖未来生态治理和引水工程中，应着重关注湖心及出湖河口处表层沉积物的迁移输运和淤积，这些区域也应是阶段性生态清淤工作的重点。研究结果为深入了解滆湖、改善滆湖生态环境、科学实施新孟河调水和长三角太湖流域环境保护提供参考。 |
| 关键词: 滆湖 沉积物性质 内源污染 氮 磷释放 |
| DOI：10.18307/2025.0325 |
| 分类号: |
| 基金项目:国家自然科学基金长江水科学研究联合项目（U2240208）；江苏省碳达峰碳中和科技创新专项（BK20220043）；中国科学院科研仪器设备研制项目（YJKYYQ20190050）联合资助 |
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| Distribution and release characteristics of endogenous pollutants in sediment of Lake Gehu, a new river-connected lake |
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Zhao Zheng，Qian Shuyu，Bai Leilei，Wang Chunliu，Jiang Helong
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1.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 211135 , P.R.China ；2.University of Chinese Academy of Sciences, Nanjing, Nanjing 211135 , P.R.China ；3.School of Environment Science and Engineering, Naniing University of Information Science and Technology, Naniing 210044 , P.R.China
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| Abstract: |
| As an emerging river-lake connection, Lake Gehu serves as an essential flood detention reservoir and a vital conduit for the Xinmeng River diversion project in the western region of the Taihu Basin. The management of Lake Gehu constitutes an essential component of the latest round of governance efforts for Lake Taihu. Thirteen sampling sites were established to investigate the nitrogen (N) and phosphorus (P) pollution status of both water and sediment in Lake Gehu, as well as the risk of internal pollutant release from the sediment. Cultivation experiments were conducted to analyze nitrogen and phosphorus release patterns and their effects. The findings indicate the following: (1) At present, the concentrations of total nitrogen (TN) ((1.43±0.27) mg/L) and total phosphorus (TP) ((0.12±0.06) mg/L) in the water are within the Class Ⅳ range. The pollution intensity is higher in the heavily developed northern lake region, with pollution decreasing spatially from north to south. (2) Currently, the comprehensive evaluation indices of TN ((1.38±0.44) mg/g) and TP ((0.34±0.07) mg/g) in sediment indicate that the entire lake is mildly polluted. Pollution is mainly concentrated in the northern tourist areas of Lake Gehu, the central region, and the areas near the outlets of Taige Canal, Caoqiao River, and Yincun Port. Sediments in these areas may be prone to siltation, with surface sediments being loose, soft, and having low shear strength. This suggests a higher potential for sediment transport and endogenous release. (3) There is a risk of endogenous nitrogen and phosphorus release from sediments, with the release effects concentrated in the first 48 hours. Nitrogen in the sediments primarily affects the nitrate nitrogen content in the overlying water, while phosphorus is released as PO4 and through the desorption of particulate organic phosphorus. The central and southern regions of the lake are critical areas for endogenous pollution. Therefore, in future ecological management and water diversion projects of Lake Gehu, special attention should be paid to the migration, transport, and deposition of surface sediments in the lake center and outlet area. These areas should also be the focus of phased ecological dredging efforts. Those findings provide a reference for an in-depth understanding of Lake Gehu, improving its ecological environment, protecting the environment of the Taihu Basin in the Yangtze River Delta, and optimizing the implementation of the Xinmeng River water diversion project. |
| Key words: Lake Gehu sediment characteristic internal pollution nitrogen and phosphorus release |
