摘要
以Cu、Pb、Zn、Cd、Cr、As和Hg 7种重金属为研究对象,均匀布点采集草海表层0~30 cm沉积物,测定样品重金属质量比,分析其空间分布,并应用地累积指数法、潜在生态风险指数法和生物效应浓度法对重金属的潜在生态风险进行了评价。结果表明,湖泊表层沉积物中Cu、Pb、Zn、Cd、Cr、As和Hg质量比分别为14.8~50.8 mg/kg、26.1~108.0 mg/kg、72.0~473.0 mg/kg、0.6~10.1 mg/kg、25.6~136.0 mg/kg、6.0~22.6 mg/kg和0.039~0.088 mg/kg,其中Cd超标率为100%,最大超标达50.5倍,为主要污染物,S1和S2两站位污染严重。Cd处于强~极强污染级别,具有强生态风险,负面生物毒性效应频繁发生;Cu、Cr、As、Pb和Zn处于无~中度污染级别,具有中等生态风险,负面生物毒性效应发生但不频繁;草海几乎不受Hg污染。空间分布上,靠近威宁县城且受人工码头航运影响的东北湖区（代表站位S1和S2）及白家嘴码头附近湖区（代表站位S4）污染严重,重金属污染分布规律大致呈由东向西逐渐降低的趋势。
This paper is attempting to present the results of an assess- ment of heavy metal contamination in the surface sediments from Cao- hal Lake, Guizhou. When we collected the surface sediment samples from the Lake, we made an assessment of the contamination level and potential ecological risks of the heavy metals were likely to bring about to the environment with the geo-accumulation index, the poten- tial ecological risk index and the sediment quality criteria, respective- ly. Furthermore, we have tested and determined the concentration rates of the heavy metals or metalloids （i.e. Cu, Pb, Zn, Cd, Cr, As and Hg） via ICP- MS and AFS in accordance with their level of contamination so that it be possible for us to identify the distribution characteristics and the likely sources of such metal pollutants. The results of our investigation showed that the content rates of the said heavy metals in the surface sediments account for 14.8 -50.8 mg/kg, 26.1- 108 mg/kg, 72- 473 mg/kg, 0.63- 10.1 mg/kg, 25.6 - 136 mg/kg, 5.99 - 22.6 mg/kg, 0.039 - 0.088 mg/kg for Cu, Pb, Zn, Cd, Cr, As and Hg, respectively. The excessive rate of Cd in accordance with the national standard can be as high as 100%. Moreover, the highest points of concentration can be 50 times as high as the primary standard of soil environmental quality by the national standard. Therefore, Cd has to be dealt with as the chief poUutant, which tends to result in harmful effects on the benthic or-ganisms, whereas the $1 and $2 around Weining County have done serious pollution under the impact of the tourist artificial port shipp- ment. The source analysis suggests that Cd, Pb, Zn have been de- rived from the anthropogenic sources, particularly the metallic discharges of the copper mine, and As was derived from the arsenic pesticide application in the surrounding farmlands. The most danger- ous form the assessment results have brought about is that Cd contam- ination reaches a very serious grade, thus becoming one of the high potential ecological risks among the fr
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第1期325-332,共8页
Journal of Safety and Environment
基金
2014年天津市科技特派员项目(14JCTPJC00475)
天津市应用基础与前沿技术研究计划面上项目(13JCYBJC20400)
中国博士后科学基金第6批特别资助项目(2013T60256)
关键词
环境学
草海
沉积物
重金属
分布特征
污染评价
environmentalology
Caohai
sediment
heavy metal
distribution charaetedstic
pollution assessment
