摘要
太湖作为一个大型富营养化湖泊,不同湖区沉积物内源污染及释放特征差异显著。以太湖草型湖区胥湖和藻型湖区竺山湖为研究对象,分析不同水深下草/藻型湖区底泥内源污染和氮磷扩散通量的变化规律。结果表明,胥湖和竺山湖沉积物中总氮含量分别为2.59~3.33 g/kg和2.95~3.63 g/kg,总磷含量分别为0.462~0.652 g/kg和0.749~0.916 g/kg。藻型湖区沉积物中营养盐含量显著高于草型湖区,且均随水深变化呈不规律波动。沉积物磷形态分析表明,胥湖沉积物中以钙结合态磷为主,且钙结合态磷在总磷中的占比随水深增加而明显下降;竺山湖沉积物中磷形态以铁结合态磷为主,且铁结合态磷、铝结合态磷和钙结合态磷在总磷中的占比随水深增加而逐步上升。胥湖浅水区域沉积物-水界面可溶性活性磷(SRP)浓度明显高于深水区域,亚铁离子(Fe^(2+))和氨氮(NH_(3)^(-)N)浓度在不同水深下差别较小;竺山湖浅水区域沉积物-水界面SRP、Fe^(2+)和NH_(3)^(-)N浓度均高于深水区域。胥湖和竺山湖内源释放风险均较小,胥湖NH_(3)^(-)N扩散通量和竺山湖SRP、NH_(3)^(-)N扩散通量均在浅水区域较高。研究结果对于深入理解水深对太湖草/藻型湖区沉积物-水界面氮、磷迁移规律具有重要作用。
Lake Taihu is a large eutrophic lake.Significant variations were observed in the endogenous pollution and release characteristics of sediments between phytoplankton-and macrophyte-dominated areas of the lake.The present study aimed to investigate and analyze the variations in endogenous pollution and nitrogen and phosphorus diffusion fluxes in Lake Xuhu(macrophyte-dominated area)and Zhushan Bay(phytoplankton-dominated area)with different water depths.The results demonstrated that:The total nitrogen content in the sediments of Lake Xuhu and Zhushan Bay was found to be between 2.59 and 3.33 g/kg and between 2.95 and 3.63 g/kg,respectively.The total phosphorus content was found to be between 0.462 and 0.652 g/kg and between 0.749 and 0.916 g/kg,respectively.The nutrient content of the sediments in the phytoplankton-dominated area was found to be significantly higher than that in the macrophyte-dominated area,and the content exhibited fluctuations that were irregular in nature with respect to changes in water depth.Phosphorus speciation analysis of sediments demonstrated that Ca-P constituted the predominant sediments in Lake Xuhu,and the proportion of Ca-P in total phosphorus exhibited a marked decrease with increasing water depth.The phosphorus morphology in the sediments of Zhushan Bay was dominated by Fe-P,and the proportions of Fe-P,Al-P and Ca-P in the total phosphorus gradually increased with the increase of water depth.The soluble active phosphorus(SRP)content at the sediment-water interface in the shallow water area of Lake Xuhu was significantly higher than that in the deep-water area,while the difference in Fe 2+and ammonia nitrogen(NH 3-N)concentrations between different water depths was relatively small.The SRP,Fe 2+and NH 3-N contents at the sediment-water interface in the shallow water area of Zhushan Bay were found to be higher than those in the deep-water area.The endogenous release risk of Lake Xuhu and Zhushan Bay was determined to be minimal,and the diffusion fluxes of NH 3-N in Lake Xuhu and SRP,NH 3-N in Zhushan Bay were found to be higher in shallow water areas.The results obtained are of great significance in understanding the nitrogen and phosphorus migration of water depth at the sediment-water interface in the phytoplankton-and macrophyte-dominated areas of Lake Taihu.
作者
宗玉清
李辉
吴东浩
石亚东
盛慧文
袁林
郭清春
邹乐
Zong Yuqing;Li Hui;Wu Donghao;Shi Yadong;Sheng Huiwen;Yuan Lin;Guo Qingchun;Zou Yue(Taihu Basin Monitoring Center of Hydrology and Water Resources,Wuxi 214024,P.R.China;Taihu Basin Shallow Lake Ecosystem Observation and Research Station,Ministry of Water Resources,Wuxi 214000,P.R.China;Key Laboratory of Taihu Basin Water Resources Management and Protection of the Ministry of Water Resources,Wuxi 214131,P.R.China;Wuxi River and Lake Management and Water Resources Management Center,Wuxi 214031,P.R.China)
出处
《湖泊科学》
北大核心
2026年第1期91-101,共11页
Journal of Lake Sciences
基金
水利部重大科技项目(SKS-2022065)资助。
关键词
藻型湖区
草型湖区
沉积物
水深
内源污染
扩散通量
Phytoplankton-dominated area
macrophyte-dominated area
sediments
water depth
endogenous pollution
diffusion flux
