Estimation for Acidification in Land Water Environment based on Neutralization of Acidic Precipitation by Soil-Analysis by Mass Transfer Theory in three phases ; gas, liquid and solid-

基于传质理论土壤分析酸性降水中和的陆地水环境酸化估算；

基本信息

批准号：
06650867
负责人：
CHOHJI Tetsuji
金额：
$ 1.28万
依托单位：
Toyama National Colleage of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

A phenomenon in which air pollutants emitted by burning fossil fuels including coal and petroleum undergo various exidation reactions in the atmosphere, producing sulfate and nitrate ions, and rainfall, snowfall and dry particulates strongly acidified by those ions fall on the earth is called "acid rain" or "acid snow" . Problesms of this phenomenon include acidification of precipitation caused by those air pollutants rather than their own toxicity. To evaluate the damage of ecosystems and buildings on the ground caused by the acidic precipitation, its acidity should be actively taken into account.In order to study a ecotechnological countermeasurement of acidic precipitaion, this research elucidates the mechanism of the neutralization of the precipitation with soil, focusing on the difference in pH between the precipitation and the water of rivers and lakes.The experiments were carried out by using a batch reactor of a cylindrial policarbonate vessel with a reaction volume of acidic s … More olution 250 ml and a column reactor with a dry soil weight of 50g. Nitric acid solutions adjusted to pH4 were prepared as the acidic solution.We obtained following results.(1) The results suggests that soil neutralize hardly acidic precipitation containing much cations. It is well known that heavy snow which contains much reasalts derived from Japan Sea covers on the Japan Sea side of Japan in winter. Therefore, we are worried the bad influence of melting snow in early spring in Japan Sea side of Japan on the quality of land waters.(2) It was found according to the column experiments that the soil neutralization ability do not only detriorate but also is able to recover.(3) The effects of carbon dioxide on neutralizaiton process of acidic precipitation with soil have been also investigated. In order to estimate the contribution of cabon dioxide contained in soil on the neutralization, column experiments were carried out under high concentration of carbon dioxide. The life of neutralization ability of soil in the column under high concentration of carbon dioxide was shorter than normal columns. Less

燃烧煤炭、石油等化石燃料排放的空气污染物在大气中强烈发生各种氧化反应，产生硫酸根、硝酸根离子，这些离子酸化的降雨、降雪和干燥颗粒物落到地球上的现象称为“酸雨”这种现象的问题包括由这些空气污染物引起的降水酸化，而不是其本身的毒性来评估对地面生态系统和建筑物的损害。为了研究酸性降水的生态技术对策，本研究阐明了降水与土壤的中和机制，重点研究了降水与土壤的pH差异。实验采用圆柱形聚碳酸酯容器间歇式反应器进行，反应体积为酸性溶液250 ml，制备干土重量为50g的硝酸溶液作为酸性溶液。我们得到以下结果。(1)结果表明，土壤很难中和含有大量阳离子的酸性沉淀。冬季，日本海沿岸含有大量来自日本海的沉积物，因此我们担心日本海沿岸早春融雪对陆地水质造成的不良影响。(2)原来是柱实验发现，土壤中和能力不但没有下降，而且还能恢复。(3)还研究了二氧化碳对土壤酸性降水中和过程的影响，以估计其贡献。对土壤中所含二氧化碳的中和能力，在高浓度二氧化碳下进行了柱实验，高浓度二氧化碳下的土壤中和能力的寿命比普通柱要短。