摘要
为精准识别富营养化湖泊中重金属(Ni、Cu、Zn、Cd及Pb)的动态分布及其对环境变化的响应机制,在分析太湖梅梁湾夏季与冬季上覆水、表层沉积物中重金属分布水平的基础上,借助薄膜扩散梯度技术(DGT)与高分辨率透析技术(HR-Peeper)重点观测了沉积物-水界面的重金属动态变化特征.结果表明,5种重金属在上覆水及表层沉积物中浓度平均值顺序大体表现为:Zn>Ni>Cu>Pb>Cd;上覆水重金属浓度、沉积物-水界面生物有效态重金属浓度(c_(DGT))及溶解态重金属浓度(cPeeper)普遍表现为夏季高于冬季.Mantel检验结果显示界面c_(DGT)与上覆水重金属浓度有较显著相关性,证实沉积物重金属迁移直接影响着上覆水重金属水平.利用冗余分析(RDA)进一步识别出调控界面重金属动态变化的关键环境因素为溶解氧(DO)、叶绿素a(Chla)、pH、沉积物pH(S_pH)和沉积物氧化还原电位(S_Eh),其中c_(DGT)-Ni、c_(DGT)-Cu、c_(DGT)-Cd和c_(DGT)-Pb与Chla和pH呈正相关,与S_pH、S_Eh和DO呈负相关,反映出夏季藻华暴发对沉积物重金属向水体迁移的显著促进.
To accurately identify the dynamic distribution of heavy metals(Ni,Cu,Zn,Cd,and Pb)in eutrophic lakes and their response mechanism to environmental changes,the distribution levels of heavy metals in the overlying water and surface sediments of Meiliang Bay in Taihu Lake were analyzed during summer and winter.Additionally,the change characteristics of heavy metals at the sediment-water interface in particular were observed using film diffusion gradient technology(DGT)and high-resolution dialysis technology(HR-Peeper).The results showed that the average concentrations of five heavy metals both in overlying water and surface sediments generally decreased in the order of Zn>Ni>Cu>Pb>Cd.The concentrations of heavy metals in the overlying water,as well as the bioavailable and dissolved concentrations of heavy metals(c_(DGT) and cPeeper)at the sediment-water interface,were generally higher in summer than in winter.The Mantel test showed significant correlations between c_(DGT) at the sediment-water interface and heavy metal concentrations in overlying water,confirming that heavy metal migration from sediment directly affected the levels of heavy metals in overlying water.Redundancy analysis(RDA)was further used to identify the key environmental factors regulating the dynamic changes of heavy metals at the sediment-water interface,including dissolved oxygen(DO),chlorophyll-a(Chla),pH,sediment pH(S_pH),and sediment redox potential(S_Eh).Among them,c_(DGT)-Ni,c_(DGT)-Cu,c_(DGT)-Cd,and c_(DGT)-Pb were mainly positively correlated with Chla and pH,and negatively correlated with S_Eh,S_pH,and DO.This reflects that algal blooms during summer significantly promoted the heavy metal migration from sediment to water.
作者
石东
王书航
姜霞
车霏霏
刘云
陈俊伊
沈东波
邢健宇
SHI Dong;WANG Shu-hang;JIANG Xia;CHE Fei-fei;LIU Yun;CHEN Jun-yi;SHEN Dong-bo;XING Jian-yu(National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,State Environment Protection Key Laboratory for Lake Pollution Control,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs,Beijing University of Agriculture,Beijing 102206,China)
出处
《环境科学》
北大核心
2025年第12期7658-7667,共10页
Environmental Science
基金
国家自然科学基金项目(41907335)。
