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The mechanism of the preferential elution of the major ion and oxygen isotope ratio in acidic snow melting water by acid shock in the snowfield of Japan

日本雪原酸性融雪水中主要离子与氧同位素比值酸激优先洗脱机制

基本信息

批准号：
12680469
负责人：
SATOW Kazuhide
金额：
$ 1.54万
依托单位：
Nagaoka National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12680469/
关键词：
acid snow (acid rain)pH cid shock ion concentration melting snow

项目摘要

(1) To recognize the reality of acidity snow, the analyses have been carried out ofacidity, electrical conductivity, major chemical features in precipitation gathered at Nagaoka City throughout the whole year from 1987. A regression straight line of the year-to-year pH variations of precipitation shows a decreasing tendency from pH value 4.9 at the end of 1987's to 4.5 at the end of 1999's. The seasonal variation of average pH value for past 13 years shows a tendency becoming high in around April and low in the winter season and June. As for why pH is low for the winter season, the effect ofa pollutant from the continent is considered to be big. The high pH value in around April is thought to be due to the influence of"Kosa". The cause of the low pH value in June is indistinct. These results are compared with that of the snow on Antarctica with little influence of human activities.(2) The relationships were examined between oxygen isotope and major ion concentration in precipitation of winter from November 1994 to March 1995. The average δ<18>^O of all precipitation is -9.3%_o, the δ<18>^O value of hail is lowest and that of rain is highest. Some strong correlations between δ<18>^O and a special ion cannot be found find, but a correlation with calcium ion was found a little.(3) The snow of Nagaoka was examined to grasp the reality of "acid shock" in Honshu covered by wet snow of large quantities. The effluence speed of an ion in the snow shows some differences by ion seed. Clear analyses in details are to be carried out in future.(4) To elucidate the reason why effluence speeds of ions are different among different ions, DSC(differential scanning calorimetry) analyses of various solutions are carried out and an interesting result was provided, but the details are indistinct.

(1)为了认识酸性雪的真实性，对1987年以来长冈市全年降水的酸度、电导率和主要化学特征进行了分析。降水pH年变化的回归直线显示，1987年末pH值为4.9,1999年末pH值为4.5，呈递减趋势。近13年平均pH值的季节变化呈现出4月左右偏高，冬季和6月偏低的趋势。至于为什么冬季pH值低，来自大陆的污染物的影响被认为是很大的。四月左右的高pH值被认为是由于“科沙”的影响。6月份pH值偏低的原因不明确。这些结果与人类活动影响较小的南极雪的结果进行了比较。(2)研究了1994年11月~ 1995年3月冬季降水中氧同位素与主要离子浓度的关系。所有降水δ<18>^O的平均值为-9.3%_o，冰雹δ<18>^O最小，降雨δ<18>^O最大。δ<18>^O与一种特殊离子之间没有很强的相关性，但与钙离子之间有一定的相关性。(3)考察了长冈的积雪，以把握本州被大量湿雪覆盖的“酸震”的现实。不同的离子种子对雪中离子的流出速度有一定的影响。今后将进行清晰的详细分析。(4)为了阐明不同离子之间离子流出速度不同的原因，对不同溶液进行了DSC（差示扫描量热法）分析，得到了一个有趣的结果，但细节不太清楚。