DEVELOPMENT OF ECONOMICAL DESIGN AND PREDICTION CONCEPT SOFT FOR DECONTAMINATION PROJECTS OF ENVIRONMENTAL CONTAMINANTS.

环境污染物净化项目经济设计和预测概念软件的开发。

基本信息

批准号：
09555171
负责人：
KUDO Akira
金额：
$ 8.83万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-09555171/
关键词：
MERCURY METHYL MERCURY MINAMATA BAY YATSUSHIRO SEA SEDIMENT 水俣拡散

项目摘要

During the last 25 years, surface sediments have been collected from 24 fixed sampling stations to a depth of 4.0cm in the Yatsusiro Sea. Researchers have found that the mercury content of the samples was not a cause for concern and that the concentrations outside the bay were below the acutely toxic level. At the same time the investigators spotted a trend in mercury behavior in the sea of 633km^2. Between 1975 and 1984 mercury concentrations gradually increased, with sampling stations close to Minamata Bay showing the greatest rise, from 0.62ppm in 1975, to 10.3ppm in 1984. At another, more remote station, concentrations rose slightly. The pattern was interrupted in 1982, an exceptional year when 400 mm of rain fell in three hours, a 200-year event. Millions of tons of clean soils were washed from surrounding mountain slopes to cover the sediments in the Yatsushiro Sea. Three years after this storm, the government initiated a decontamination project. Mercury concentrations at one sampling station near the bay dropped from 10.5 to 1.56ppm from 1985 to 1990 and decreased further to a background level of 0.3ppm in 1997. The Japanese government eventually took responsible action against mercury pollution in the bay, but it was too slow to act. The decontamination project costing US$500 million and the first such effort in the world, will not only clean up the bay and protect the people around the Yatsushiro Sea for many years to come.

在过去的25年中，从24个固定采样站收集了表面沉积物，到Yatsusiro Sea的深度为4.0厘米。研究人员发现，样品的汞含量并不是引起关注的原因，海湾外的浓度低于急性毒性水平。同时，调查人员发现了633公里^2的海中汞行为的趋势。在1975年至1984年之间，汞浓度逐渐增加，采样站接近Minamata湾，显示出最大的上升，从1975年的0.62ppm到1984年的10.3ppm。在另一个更偏远的站点，浓度略有上升。该模式在1982年被打断，这是一个异常的一年，当时有400毫米的降雨在三个小时内下降了200年。从周围的山坡上洗涤了数百万吨干净的土壤，以覆盖Yatsushiro海中的沉积物。这场风暴发生三年后，政府发起了一个去污项目。从1985年到1990年，海湾附近一个采样站的汞浓度从10.5跌至1.56ppm，并在1997年进一步降至背景水平为0.3ppm。日本政府最终采取了针对海湾汞污染的负责任行动，但采取行动太慢了。净化项目耗资5亿美元，是世界上第一个这样的努力，不仅将清理海湾并保护未来多年的Yatsushiro Sea周围的人们。