Estimation of the residual total mercury in marine sediments of Minamata Bay after a pollution prevention project
Estimation of the residual total mercury in marine sediments of Minamata Bay after a pollution prevention project
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DOI：
10.1016/j.marchem.2013.12.002
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发表时间：
2014-02
期刊：
影响因子：
3
通讯作者：
T. Tomiyasu;Shinya Takenaka;Y. Noguchi;Hitoshi Kodamatani;A. Matsuyamab;K. Ōki;Yuriko Kono;R. Kanzaki;H. Akagi
中科院分区：
文献类型：
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作者：
T. Tomiyasu;Shinya Takenaka;Y. Noguchi;Hitoshi Kodamatani;A. Matsuyamab;K. Ōki;Yuriko Kono;R. Kanzaki;H. Akagi
为了估计水俣湾当前的污染水平，对沉积物中汞的垂直和水平分布进行了研究。沉积物岩心样品于2002年、2006年、2008年和2010年在水俣湾和位于水俣湾南部的袋湾的12个地点通过重力岩心取样采集。水俣湾和袋吕湾每年表层沉积物中的平均总汞浓度分别为 2.47–3.34 和 3.50–4.66 mg kg−1；在研究期间没有观察到数值的显着变化。袋吕湾的总汞浓度随着深度的增加而增加，在距地表 8-14 厘米处达到最大值，并随着深层深度的增加而降低。在水俣湾，从表面到 10 厘米深度的总汞浓度没有显着变化，并且该值远高于背景水平。在两个区域的长岩心的下层中，总汞浓度随着深度的增加而降低，并且最深层表现出相对均匀的低值。这些值可以被认为代表在没有人为影响的情况下的背景浓度。水俣湾和袋吕湾受污水影响的沉积物深度估计分别为 20 ± 7 厘米和 33 ± 4 厘米。此外，根据污染层的平均浓度和体积估计，两个海湾的沉积物中残留有约1吨排放的汞。
To estimate the current contamination levels in Minamata Bay, the vertical and horizontal distributions of mercury in the sediment were investigated. Sediment core samples were collected in 2002, 2006, 2008, and 2010 at 12 locations by gravity core sampling in Minamata Bay and Fukuro Bay, which is located in the southern part of Minamata Bay. The average total mercury concentrations during each year in the surface sediment were 2.47–3.34 and 3.50–4.66 mg kg− 1for Minamata Bay and Fukuro Bay, respectively; significant variation in the values was not observed during the study period. The total mercury concentration in Fukuro Bay increased with increasing depth and reached a maximum at 8–14 cm from the surface and decreased with increasing depth in the deeper layer. In Minamata Bay, the total mercury concentration did not change significantly from the surface to a depth of 10 cm and the values were considerably higher than the background level. In the lower layers of the long cores taken from both areas, the total mercury concentration decreased with depth, and the deepest layers exhibited relatively uniform low values. These values can be considered to represent the background concentration in the absence of anthropogenic influence. The depth of the sediment affected by the effluent was estimated to be 20 ± 7 cm and 33 ± 4 cm for Minamata Bay and Fukuro Bay, respectively. Furthermore, it was estimated from the average concentration and volume of the contaminated layer that approximately 1 ton of discharged mercury remained in the sediment of the two bays.