洞庭湖及其入湖口沉积物中重金属的污染特征、来源与生态风险

发布时间：2019-02-19 10:33

【摘要】：选择洞庭湖及9个入湖口为研究区,分析了沉积物中Tl、Sb、Hg、Cd、As、Pb、Cu、Ni和Cr等9种重金属的空间分布、来源、污染特征与潜在生态风险.结果表明,入湖口沉积物中各重金属含量在0.08—100 mg·kg~(-1)之间,洞庭湖全湖沉积物中Tl、Sb、Hg、Cd、As、Pb、Cu、Ni和Cr的平均含量分别为背景值的1.47、2.33、5.55、8.30、2.32、2.17、1.98、1.60和1.58倍,其中Cd、Hg、Sb和As的富集程度相对较高.湖体沉积物中Tl、Sb、As、Cu和Cr空间分布表现为南洞庭湖东洞庭湖西洞庭湖;Hg、Cd和Ni空间分布表现为南洞庭湖西洞庭湖东洞庭湖;Pb的空间分布为东洞庭湖南洞庭湖西洞庭湖.来源分析得出东洞庭湖沉积物中重金属主要受湘江来水的影响;南洞庭湖沉积物中重金属受湘江和资江的共同影响;西洞庭湖沉积物中重金属来源较复杂.污染负荷指数法得出:入湖口污染程度(PLI值)大小为S1S2S3S4S8S5S9S6S7;湖体污染程度(PLI_((area))值)大小为南洞庭湖东洞庭湖西洞庭湖.洞庭湖全湖受到强污染(PLI_((area))值2.22),各重金属的污染程度(CF值)大小为CdHgSbAsPbCuNiCrTl.入湖口生态风险大小为S1S2S3S8S4S9S6S5S7;湖体生态风险大小为南洞庭湖东洞庭湖西洞庭湖.洞庭湖全湖生态风险指数为689.3,属"严重"生态风险.各重金属的生态风险大小为CdHgSbTlAsPbCuNiCr,主要风险污染物是Cd和Hg,其次为Sb和Tl.综合研究表明,S1、S2、S13、S14、S15、S19、S20、S22、S24和S25采样区污染严重,已成为"严重"生态风险区域.
[Abstract]:The spatial distribution, source, pollution characteristics and potential ecological risk of nine heavy metals, such as Tl,Sb,Hg,Cd,As,Pb,Cu,Ni and Cr in sediments, were analyzed in Dongting Lake and 9 estuaries of Dongting Lake. The results showed that the contents of heavy metals in the sediments of the estuary of Dongting Lake ranged from 0.08-100 mg kg~ (-1), and Tl,Sb,Hg,Cd,As,Pb,Cu, in the sediments of Dongting Lake were found to be in the range of 0.08-100 mg kg~ (-1). The average contents of Ni and Cr were 1.47 ~ 2.33 ~ 5.55 ~ 8.30 ~ 2.32 ~ 1.98 ~ 1.60 and 1.58 times of background value, respectively. The enrichment degree of Cd,Hg,Sb and As was relatively high. The spatial distribution of Tl,Sb,As,Cu and Cr in lake sediments is as follows: East Dongting Lake, West Dongting Lake, and Hg,Cd and Ni spatial distribution in South Dongting Lake, West Dongting Lake and East Dongting Lake. The spatial distribution of Pb is East Dongting Lake South Dongting Lake West Dongting Lake. The source analysis shows that the heavy metals in the sediments of the East Dongting Lake are mainly affected by the water from the Xiangjiang River, the heavy metals in the sediments of the South Dongting Lake are affected by the Xiangjiang River and the Zijiang River, and the sources of the heavy metals in the sediments of the West Dongting Lake are complex. The pollution load index method shows that the pollution degree (PLI value) is S1S2S3S4S4S8S5S9S6S7 and the PLI_ (area) value is the East Dongting Lake and the West Dongting Lake in the South Dongting Lake. Dongting Lake was heavily polluted (PLI_ (area) 2.22), and the degree of heavy metal pollution (CF) was CdHgSbAsPbCuNiCrTl.. The ecological risk at the mouth of the lake is S1S2S3S8S4S9S6S5S7 and the ecological risk of the lake body is the south Dongting lake, the east Dongting lake and the west Dongting lake. The ecological risk index of Dongting Lake is 689.3, which belongs to "serious" ecological risk. The ecological risk of each heavy metal is CdHgSbTlAsPbCuNiCr,. The main risk pollutants are Cd and Hg,. The next are Sb and Tl.. The comprehensive study shows that the sampling areas of S1 / S2, S13, S14, S15, S19, S20, S22, S24 and S25 are seriously polluted and have become "serious" ecological risk areas.
【作者单位】：湖南省洞庭湖生态环境监测中心;
【基金】：2014年湖南省环境保护厅科技计划项目(2014-16)资助~~
【分类号】：X524;X826

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