长荡湖入湖河流底泥污染特征和潜在生态风险评价  

Characteristics of sediment pollution and assessment of potential risk in rivers flowing into Changdang Lake

作　　者：都诚 夏玉林[3] 谢得宝 陈辉 陆海明[4] 杨剑 王凯 唐文忠[2] 张洪[2] DU Cheng;XIA Yulin;XIE Debao;CHEN Hui;LU Haiming;YANG Jian;WANG Kai;TANG Wenzhong;ZHANG Hong(College of Urban and Environmental Sciences,Central China Normal University,Wuhan 430000,China;State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Changzhou Branch of Jiangsu Hydrology and Water Resources Survey Bureau,Changzhou 213022,China;Nanjing Hydraulic Research Institute,Research center on hydrology and water resources of Ministry of water resources,Nanjing 210029,China;Jiangsu Jintan Changdang Lake Tourism Resort Management Office,Changzhou 213022,China)

机构地区：[1]华中师范大学城市与环境科学学院,武汉430000 [2]中国科学院生态环境研究中心,环境水质学国家重点实验室,北京100085 [3]江苏省水文水资源勘测局常州分局,常州213022 [4]南京水利科学研究院,水利部水文水资源工程技术研究中心,南京210029 [5]江苏省金坛长荡湖旅游度假区管理办公室,常州213200

出　　处：《环境工程学报》2023年第12期3849-3858,共10页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(52270202,41877471);江苏省水利科技项目(2021013)。

摘　　要：选择长荡湖入湖河流为研究对象,分析河流底泥营养盐、有机质和重金属的分布特征,采用潜在生态风险指数法评价底泥重金属的潜在污染风险水平。结果表明,长荡湖入湖河流底泥中总氮和总磷均低于流域背景的平均水平,分别为1 134.15和664.81 mg·kg^(-1),氮、磷化学计量比(N/P=1.96)也低于我国不同纬度典型的湖泊底泥平均水平(N/P=3.89~9.57),且所有底泥中总磷都存在较高的污染负荷。有机质的平均质量分数为1.23%,除方洛港外,整体质量分数相对较低,与总磷和总氮强相关。入湖河流底泥中重金属的平均质量分数高于背景值,特别是新河港、方洛港和大浦港,其中Cu、Zn、Cd和Hg的平均质量分数显著高于流域背景值,分别为48.25、163.47、0.37和0.12 mg·kg^(-1)。潜在污染风险主要存在于新河港和方洛港,其风险指数分别为328.8和222.26。方洛港存在潜在污染风险的底泥主要集中在深层底泥的45 cm以下,且赋存了大量的营养盐,人为干扰可能再次释放营养盐,故不建议实施清淤工程。该研究结果可为同类湖泊水质监管与治理提供参考。This study focuses on the rivers flowing into Changdang Lake(CDL),analyzing the distribution characteristics of nutrients,organic matter,and heavy metals in river sediments.The potential ecological risk of heavy metals was also assessed.The results indicated that the mass fraction of total nitrogen and total phosphorus in the sediments of rivers entering CDL was lower than the average levels of the watershed background,standing at 1134.15 and 664.81 mg·kg^(-1),respectively.The stoichiometric ratios of nitrogen and phosphorus(N/P=1.96)were also lower than the average level of sediments in typical lakes at different latitudes in China(N/P=3.89~9.57),and a high pollution load of total phosphorus was observed in all sediments.The average mass fraction of organic matter was 1.23%,and except for Fangluo Port,the overall mass fraction was relatively low,showing a strong correlation with total phosphorus and total nitrogen.The average mass fractions of heavy metals in the sediment of rivers entering the lake were higher than the background value,especially in Xinhe Port,Fangluo Port,and Dapu Port.Among them,the average mass fraction of Cu,Zn,Cd,and Hg significantly exceeded the watershed background values,standing at of 48.25,163.47,0.37,and 0.12 mg·kg^(-1),respectively.Potential pollution risks were mainly present in Xinhe Port and Fangluo Port,with risk indices of 328.8 and 222.26,respectively.In Fangluo Port,sediment posing potential pollution risks was primarily concentrated below 45 cm of the deep sediment layer,which also contained a large number of nutrients.Artificial disturbances may release nutrients again,so dredging is not recommended.

关 键 词：环保清淤 长荡湖 垂直分布 入湖河流 太湖流域 

分 类 号：X524[环境科学与工程—环境工程]