牛栏江(昆明段)表层沉积物重金属时空分布特征与潜在生态风险评价  

Spatial and Temporal Distribution Characteristics of Heavy Metals in Surface Sediments of Niulan River(Kunming Section)and Potential Ecological Risk Assessment

作　　者：李昕悦 杨艳 洪昌海 支国强 杨健 韩镇阳 万正芬[3] 卢少勇[3] LI Xin-yue;YANG Yan;HONG Chang-hai;ZHI Guo-qiang;YANG Jian;HAN Zhen-yang;WAN Zheng-fen;LU Shao-yong(Kunming Research Academy of Eco-Environmental Sciences,Kunming 650032,China;Yunnan Water Resources and Hydropower Vocational College,Kunming 650400,China;Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]昆明市生态环境科学研究院,昆明650032 [2]云南水利水电职业学院,昆明650400 [3]中国环境科学研究院,北京100012

出　　处：《长江科学院院报》2024年第11期32-40,48,共10页Journal of Changjiang River Scientific Research Institute

摘　　要：为探明牛栏江(昆明段)表层沉积物重金属污染特征,于3个水期(丰水期、枯水期、平水期)分别采集了流域内20个点位表层沉积物并测定了8种金属(Cu、Zn、Cr、Cd、Ni、Pb、Hg、As)含量,进行了水期和区域差异分析、潜在风险评价以及重金属来源解析。结果发现牛栏江(昆明段)沉积物重金属中Cd含量1.45 mg/kg和Hg含量0.23 mg/kg,分别是云南省土壤背景值(0.218 mg/kg和0.058 mg/kg)的6.7倍和4.0倍,表明Cd和Hg污染相对严重。地累积指数表明牛栏江(昆明段)3个水期均为Cd污染程度最高,Hg次之,平均污染等级分别达到了中度污染和偏中度污染。因此Cd和Hg是牛栏江(昆明段)表层沉积物重金属污染最主要的生态风险贡献因子,应予以重视。同时,潜在生态风险指数表明,丰水期和平水期潜在生态风险程度分布具有干流高于支流、下游高于上游和北部高于南部的空间特征。In order to explore the characteristics of heavy metal pollution in surface sediments of Niulan River(Kunming Section),the surface sediments of 20 points in the basin were collected;and the contents of 8 metals(Cu,Zn,Cr,Cd,Ni,Pb,Hg and As)were determined in three water periods(wet period,dry period and normal period).Water stage and regional difference analysis,potential risk assessment and heavy metal source analysis were also carried out.The results showed that the content of Cd(1.45 mg/kg)and Hg(0.23 mg/kg)of heavy metals in sediments of Niulan River(Kunming Section)was 6.7 times and 4.0 times that of the background values 0.218 mg/kg and 0.058 mg/kg in Yunnan Province,respectively.It indicates that Cd and Hg pollution are relatively serious.The soil accumulation index showed that Cd had the highest pollution level in the three water periods of Niulan River(Kunming Section),followed by Hg.The average pollution levels reached moderate pollution and moderately moderate pollution,respectively.Therefore,Cd and Hg are the main ecological risk contributing factors of heavy metal pollution in surface sediments of Niulan River(Kunming Section).At the same time,the potential ecological risk coefficient showed that the distribution of potential ecological risk was higher in the main stream than in the tributaries,higher in the lower stream than in the upper stream and higher in the north than in the south.

关 键 词：表层沉积物 重金属 地累积指数 潜在生态风险 牛栏江(昆明段) 

分 类 号：X522[环境科学与工程—环境工程]