摘要
为探明城市湖泊湿地的生态环境现状,采用数理统计、地累积指数和潜在生态风险指数等方法,对武汉市龙阳湖、墨水湖表层沉积物中的氮、磷和重金属的富集程度、空间分布及生态风险进行了评价.结果显示,来自龙阳湖的表层沉积物中TN浓度为265.03~729.68mg/kg、TP浓度为888.64~1694.86mg/kg;来自墨水湖的表层沉积物TN浓度为306.14~857.27mg/kg、TP浓度为671.48~2674.39mg/kg.总的来说,墨水湖沉积物受污染程度比龙阳湖较高.与国内典型城市湖泊相比,本研究的两个湖泊中TN含量较低,TP含量较高.重金属元素As、Cd、Cr、Cu、Pb和Zn在龙阳湖中分别为14.27,0.58,59.20,55.61,33.20,176.94mg/kg,在墨水湖中分别为19.26,0.62,85.53,53.67,41.69,266.64mg/kg.除Cr外,沉积物中其它重金属平均含量均高于武汉市土壤背景值,且龙阳湖、墨水湖Cd含量分别是背景值的4.83和5.17倍.与20年前相比,除Cd以外,墨水湖沉积物重金属含量均有减少,表明淤泥清理对改善湖泊沉积物环境有一定效果,但未从根本上消除污染问题.重金属地累积指数显示,两湖泊中Cd含量均处于偏中度至中度污染状态;Cu、Pb、Zn、As总体上处于轻度污染状态;Cr处于清洁状态.潜在生态风险指数显示,两湖泊Cd含量均处于中度至重度潜在生态风险水平,综合潜在生态风险为低风险至中风险.研究区湖泊中的重金属污染物来源可能为早期工业排放、渔业养殖、动物粪便及人类生活污水的排放等综合因素所致.
In order to assess the current status of the ecological environment of urban lake wetlands,the present study employs various methods,including mathematical statistics,ground accumulation index,and potential ecological risk index.These methods are used to evaluate the enrichment levels,spatial distributions,and ecological risks of nitrogen,phosphorus,and heavy metal elements in the surface sediments of Longyang Lake and Moshui Lake,located in Wuhan,China.The results indicate that the surface sediment samples from Longyang Lake have total nitrogen(TN)and total phosphorus(TP)contents ranging from 265.03to 729.68mg/kg and 888.64 to 1694.86mg/kg,respectively.On the other hand,Moshui Lake samples have TN and TP contents ranging from 306.14 to 857.27mg/kg and 671.48 to 2674.39mg/kg,respectively.Thus,Moshui Lake exhibits higher pollution levels compared to Longyang Lake.Moreover,when compared to typical lakes in other domestic cities,both Longyang Lake and Moshui Lake exhibit low TN and high TP contents in their sediments.The concentrations of As,Cd,Cr,Cu,Pb,and Zn in Longyang Lake are 14.27mg/kg,0.58mg/kg,59.20mg/kg,55.61mg/kg,33.20mg/kg,and 176.94mg/kg,respectively.In Moshui Lake,the concentrations of these elements are 19.26mg/kg,0.62mg/kg,85.53mg/kg,53.67mg/kg,41.69mg/kg,and 266.64mg/kg,respectively.Additionally,the average concentration of heavy metal elements in the surface sediments,except for Cr,exceeds the background levels of soil in Wuhan.Moreover,the Cd content in Longyang Lake and Moshui Lake are significantly higher than the background values,being 4.83 and 5.17times greater,respectively.Comparing the current conditions with those from 20 years ago,it is evident that the content of heavy metal elements(except Cd)in Moshui Lake's sediments has decreased.This suggests that efforts to clean the lake's mud have improved the sediment conditions,although pollution has not been completely eliminated.The accumulated index indicates that the Cd level in both lakes is in a roughly moderate polluted state,while Cu,Pb,Zn,and As are generally in a mildly polluted state,and Cr is in a clean state.The potential ecological risk index suggests that the overall potential ecological risk is at a low to medium level,but the Cd content in both lakes poses a moderate to severe risk.The study area's heavy metal elemental pollutants may be sourced from a combination of fluxes,including early industrial discharge,fishery farming,animal feces,and emissions from human domestic sewage.
作者
周峰
李朋
翁茂芝
邢新丽
刘力
张雅
朱晛亭
罗红
ZHOU Feng;LI Peng;WENG Mao-zhi;XING Xin-li;LIU Li;ZHANG Ya;ZHU Xian-ting;LUO Hong(Hubei Geological Survey,Wuhan 430034,China;Hubei Key Laboratory of Resources and Eco-environment Geology(Hubei Geological Bureau)Wuhan,Hubei 430074;School of Environmental Studies,China University of Geosciences,Wuhan 430074,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第10期5533-5543,共11页
China Environmental Science
基金
武汉市多要素城市地质调查示范项目(WHDYS-2021-007)。
关键词
湖泊沉积物
重金属元素
生态风险评价
龙阳湖
墨水湖
lake sediment
heavy metal elements
ecological risk assessment
Longyang Lake
Moshui Lake
