The Chemistry of Hydrogen Peroxide in Cloudwater

在过去的十年里，酸雨已经成为一个主要的问题。由于溶解的二氧化碳，雨具有天然的酸性。由于人类活动所排放的某些气体，雨的酸度变得更大。燃煤电厂排放大量的二氧化硫，高温燃烧过程，如汽车发动机，产生氮氧化物。这些气体最终转化为酸。描述将这些气体转化为酸的化学过程和这些反应的速度是理解酸雨的地理分布和前体气体的特定来源的影响的重要关键。二氧化硫溶解成水滴，水滴为二氧化硫氧化成酸提供了化学介质。在这个反应中一个重要的物质是过氧化氢。因此，了解过氧化氢在大气中形成和破坏的机制是很重要的。过氧化氢是高度可溶的，已知对植物有有害影响。与过氧化氢的气相化学相反，液滴中的化学还不太清楚。该项目侧重于研究过氧化氢的水化学，重点是在近似云水中发现的条件下形成和破坏过氧化氢的反应的实验室研究。化学将通过合成沉淀物中的辐射分解技术进行研究，即已知成分近似于云水的水溶液。这些实验室研究将为检验各种云化学模型的适用性提供数据。

Acid rain has become a major concern during the past decade. Rain has a natural acidity due to dissolved carbon dioxide. The acidity of rain is made even greater by the emission of certain gases from human endeavors. Coal burning power plants emit substantial quantities of sulfur dioxide and high temperature combustion processes, such as automobile engines, yield nitrogen oxides. These gases are eventually converted into acids. A description of the chemical processes involved in changing these gases into acids and the speed of these reactions are important keys to understanding the geographic distribution of acid rain and the impact of particular sources of the precursor gases. Sulfur dioxide dissolves into water droplets which provide a chemical medium for the oxidation of sulfur dioxide into acid. A vital species in this reaction is hydrogen peroxide. It is therefore important to understand the mechanisms by which hydrogen peroxide is formed and destroyed in the atmosphere. Hydrogen peroxide is highly soluble and is known to have deleterious effects on plants. In contrast to the gas phase chemistry of hydrogen peroxide, the chemistry in droplets is not well understood. This project focuses on examining the aqueous chemistry of hydrogen peroxide with emphasis on laboratory studies of the reactions that form and destroy hydrogen peroxide under conditions approximating those found in cloudwater. The chemistry will be investigated by the technique of radiolysis in synthetic precipitation, i. e., aqueous solutions of known composition approximating that of cloudwater. These laboratory studies will provide data to test the applicability of various models of cloud chemistry.