摘要
为了研究长江中游湖泊中表层沉积物的汞污染问题,2015年春季,在湖北省黄石市的磁湖、大冶湖、网湖、朱婆湖和保安湖共布设了47个采样点,采集了表层(0~10 cm深度)沉积物样品,测定和计算出沉积物样品中总汞和各形态汞含量;采用地累积指数法、潜在生态风险指数法和次生相与原生相分布比值法,研究了5座湖泊表层沉积物中汞的分布特征、生物有效性及其潜在生态风险。研究结果表明,磁湖表层沉积物的汞污染相对最严重,8个采样点的平均总汞质量比达到了271.33μg/kg;朱婆湖表层沉积物的汞污染相对最轻微,5个采样点的平均总汞质量为58.28μg/kg;除了朱婆湖之外,其它4座湖泊表层沉积物的平均总汞含量值都超过了土壤背景值和湖芯背景值;距离城市越近,湖泊表层沉积物的汞污染程度相对越严重;5座湖泊表层沉积物中汞的赋存形态以强有机态为主,强有机态汞含量占总汞含量的比例为53.97%~87.63%;5座湖泊表层沉积物的平均生物可利用态汞含量为48.2~253.0μg/kg,其占总汞含量的比例为82.0%~93.1%;在5座湖泊中,朱婆湖表层沉积物的汞污染水平较低,保安湖和网湖表层沉积物的汞污染水平为中度汞污染,大冶湖和磁湖表层沉积物的汞污染水平为重度汞污染,其表层沉积物中的汞都具有较高的生物活性,因此,具有较强的潜在生态危害;5座湖泊表层沉积物中汞的迁移和转化风险较高,在沉积环境发生变化时,可能对湖泊水体带来较大的生态危害。
In order to understand the pollution characteristic of mercury in the surface sediments of 5 Lakes in northeastern Hubei province, 47 surface sediment samples were collected from Ci Lake, Daye Lake, Wang Lake, Baoan Lake and Zhupo Lake on April 25 and May 16 in 2015. The contents and various forms of mercury were measured to illustrate the distribution characteristics, bioavailability and potential ecological risk of mercury by geo-accumulation index, potential ecological risk index and secondary/primary ratio methods. The results indicated that the mean values of total mercury in the surface sediments of Ci Lake,Daye Lake, Wang Lake, Baoan Lake and Zhupo Lake were 271.3 μg/kg, 186.9 μg/kg, 115.9 μg/kg, 88.8 μg/kg and 58.3 μg/kg, respectively, which were 0.68-3.15 times of background value. And the mercury contents showed the obvious spatial differences compared within 5 lakes due to the change of distance between these lakes and the urban;strong organic matter state was the main form of mercury in these lakes in the region,with an average content of 31.3-238.6 μg/kg, accounting for 54.0%-87.6% of their total mercury contents. The average content of bioavailable mercury in the surface sediments of 5 lakes was 48.2-253.0 μg/kg, accounting for 82%-93.1% of their total mercury contents;the results of geo-accumulation index method, potential ecological index method and secondary/primary ratio method showed that the mercury pollution level in Zhupo Lake in this area was low, while Baoan Lake and Wanghu Lake were moderately polluted, however,the mercury contents in the surface sediments in Daye Lake and Ci Lake had high biological activity, which may lead to higher ecological risk of mercury pollution. The mercury pollution of lakes in this area deserves attention.
作者
陈虎阳
阮超越
薛钧
尹刚
桂智凡
CHEN Huyang;RUAN Chaoyue;XUE Jun;YIN Gang;GUI Zhifan(College of Urban and Environmental Sciences,Hubei Normal University,Huangshi 435002,Hubei,P.R.China;Research Center for Resource Depletion and Urban Transformation and Development of Hubei Normal University,Huangshi 435002,Hubei,P.R.China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,Fujian,P.R.China)
出处
《湿地科学》
CSCD
北大核心
2022年第2期285-294,共10页
Wetland Science
基金
国家自然科学基金项目(41402152)
湖北省自然科学基金项目(2013CFB062)
湖泊与环境国家重点实验室开放基金项目(2014SKL003)
资源枯竭城市转型与发展研究中心开放基金项目(Kf2016z04)
湖北师范大学湖泊流域重金属污染机理与生态修复创新团队项目资助。
关键词
沉积物
汞
赋存形态
污染
潜在生态风险
湖泊
黄石市
sediments
mercury
occurrence form
pollution
potential ecological risk
lake
Huangshi city
