Spatial variations of mercury in sediment of Minamata Bay, Japan
Spatial variations of mercury in sediment of Minamata Bay, Japan
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DOI：
10.1016/j.scitotenv.2005.09.090
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发表时间：
2006-09-01
影响因子：
9.8
通讯作者：
Akagi, Hirokatsu
中科院分区：
文献类型：
--
作者：
Tomiyasu, Takashi;Matsuyama, Akito;Akagi, Hirokatsu
在1968年之前的大约40年时间里，一家化工厂向水俣湾排放了受汞污染的污水。1977年10月，启动了水俣湾污染防治项目，处理汞浓度高于25 mg kg（-1）的沉积污泥。1990年3月，该项目完成。为了估计海湾中目前的污染情况，研究了沉积物中汞的垂直和水平分布。2002年6月26日，在水俣湾和水俣湾南部福古湾的16个地点采集了沉积物岩心样本。福古湾的沉积物还没有疏浚。水俣湾疏浚区表层沉积物总汞浓度为1.4 ~ 4.3 mg kg(-1) (2.9 +/- 0.9 mg kg(-1), n= 9)，福古湾疏浚区表层沉积物总汞浓度为0.3 ~ 4.8 mg kg(-1) （3.6 +/- 1.6 mg kg(-1), n=4）。在两个地区的长岩心下部，总汞浓度随深度下降，最终呈现相对均匀的低值。这些值可以被认为代表没有人为影响的背景浓度，研究区域的背景浓度估计为0.068 +/- 0.012 mg kg(-1) （n = 10）。从表层看，Fulcuro湾总汞浓度随深度增加，在8 ~ 14 cm处达到最大值。在水俣湾，离水面几厘米的汞总浓度没有明显变化，其值明显高于背景水平。在六个站点，测定了甲基汞浓度。虽然垂直变化与总汞相似，但福郎湾沉积物的甲基汞浓度高于水俣湾沉积物。(c) 2005 Elsevier B.V.版权所有
Mercury-contaminated effluent was discharged into Minamata Bay from a chemical plant over a period of approximately 40 years until 1968. In October 1977, the Minamata Bay Pollution Prevention Project was initiated to dispose of sedimentary sludge containing mercury concentrations higher than 25 mg kg(-1). In March 1990, the project was completed. In an effort to estimate current contamination in the bay, the vertical and horizontal distributions of mercury in sediment were investigated. Sediment core samples were collected on June 26, 2002 at 16 locations in Minamata Bay and Fukuro Bay located in the southern part of Minamata Bay. The sediment in Fukuro Bay had not been dredged. The total mercury concentration in surface sediment was 1.4-4.3 mg kg(-1) (2.9 +/- 0.9 mg kg(-1), n =9) for the dredged area of Minamata Bay and 0.3-4.8 mg kg(-1) (3.6 +/- 1.6 mg kg(-1), n=4) for Fukuro Bay. In the lower layers of long cores taken from both areas, the total mercury concentration decreased with depth and finally showed relatively uniform low values. These values can be considered to represent the background concentration absent of anthropogenic influence, which was estimated for the study area to be 0.068 +/- 0.012 mg kg(-1) (n = 10). From the surface, the total mercury concentration in Fulcuro Bay increased with depth and reached a maximum at 8-14 cm. In Minamata Bay, several centimeters from the surface the total mercury concentration did not change significantly having considerably higher values than the background level. At six stations, the methylmercury concentration was determined. Although the vertical variations were similar to those for total mercury, Fukuro Bay sediment showed a higher concentration of methylmercury than Minamata Bay sediment. (c) 2005 Elsevier B.V. All rights reserved.