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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年里，从Yatsusiro海的24个固定采样站采集了深度为4.0厘米的表层沉积物。研究人员发现，样本中的汞含量并不令人担忧，而且海湾以外的浓度低于剧毒水平。与此同时，调查人员发现了汞在633平方公里2海域的行为趋势。1975至1984年间，汞浓度逐渐增加，水手湾附近的采样站显示出最大的上升趋势，从1975年的0.62ppm上升到1984年的10.3ppm。在另一个更偏远的站点，浓度略有上升。这种模式在1982年被打断，这是一个特殊的年份，三个小时内降雨量达到400毫米，这是200年一遇的事件。数以百万计的清洁土壤被从周围的山坡上冲走，覆盖在八城海的沉积物上。这场风暴发生三年后，政府启动了一项净化项目。从1985年到1990年，海湾附近一个采样站的汞浓度从10.5降至1.56ppm，1997年进一步降至0.3ppm的本底水平。日本政府最终对墨西哥湾的汞污染采取了负责任的行动，但行动太慢了。这项耗资5亿美元的净化项目是世界上第一个这样的项目，它不仅将清理海湾，并在未来许多年保护Yatsushiro海周围的人民。