RUI: Hydrogen Peroxide Variability in Coastal Rainwater

RUI：沿海雨水中过氧化氢的变化

• 批准号: 9320971
• 负责人: Joan Willey
• 金额: $ 13.47万
• 依托单位: University of North Carolina at Wilmington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1997-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9320971&HistoricalAwards=false
• 关键词: RUI; Hydrogen; Peroxide; Variability; Coastal

9320971 Willey This research will investigate the chemical composition of rainwater in coastal North Carolina. This location is ideal for rainwater research because it receives precipitation of both continental and maritime origins. Previous work has shown that these two general source types are compositionally very different with respect to inorganic ions as well as formic and acetic acids. The specific objective of this study is to define patterns of variation in the rainwater concentrations of the strong oxidant hydrogen peroxide (H2O2). At this time the factors controlling the concentration of H2O2 in maritime and continental storms are poorly defined and unpredictable. The question addressed in this research project is whether H2O2 concentrations are greater in rain of marine or continental origin. It could be argued that H2O2 levels would be lower in continental rain because it can oxidize sulfur dioxide to sulfuric acid and nitrogen oxides to nitric acid, thereby resulting in a net loss of H2O2. Hydrogen peroxide is, however, photochemically produced along with other pollutant atmospheric oxidants, which would increase its concentration in rain of continental origin. The relative concentrations of H2O2 in continental versus maritime rain must be defined to allow global modeling of many important atmospheric oxidants. Hydrogen peroxide is involved in cycles of other stronger atmospheric oxidants including the formation of hydroperoxyl radical and the destruction of hydroxyl radical. Model calculations suggest that concentrations of strong atmospheric oxidants may increase dramatically during the next decade because of stratospheric ozone losses at temperate latitudes. Hence, this is a particularly timely project. Rainwater and atmospheric condensate are appropriate media for the study of H2O2 due to its large water solubility. For example, hydrogen peroxide is often present in rainwater at micromolar concentrations. It is st able in rain for time periods of hours, which makes this laboratory well suited for the project because of the proximity of the collection sites and the analytical laboratory. There is approximately a decade of rainwater composition data for one of the North Carolina sites. This relatively long term data record will be useful in interpretation of new measurement data and will also facilitate comparisons with other sampling locations. ***

[320971] Willey这项研究将调查北卡罗来纳州沿海地区雨水的化学成分。这个位置是进行雨水研究的理想地点，因为它同时接收来自大陆和海洋的降水。以前的工作表明，这两种一般来源类型在无机离子以及甲酸和乙酸的组成上非常不同。本研究的具体目的是确定雨水中强氧化剂过氧化氢（H2O2）浓度的变化模式。目前，控制海洋和大陆风暴中H2O2浓度的因素定义不清，也无法预测。在这个研究项目中要解决的问题是H2O2浓度在海洋还是大陆降雨中更高。可以说，大陆雨中的H2O2含量会更低，因为它可以将二氧化硫氧化成硫酸，将氮氧化物氧化成硝酸，从而导致H2O2的净损失。然而，过氧化氢是与其他污染大气氧化剂一起光化学产生的，这将增加其在大陆源性降雨中的浓度。必须确定大陆和海洋降雨中H2O2的相对浓度，以便对许多重要的大气氧化剂进行全球模拟。过氧化氢参与了其他强大气氧化剂的循环，包括氢过氧自由基的形成和羟基自由基的破坏。模式计算表明，由于温带地区平流层臭氧的损失，未来十年强大气氧化剂的浓度可能急剧增加。因此，这是一个特别及时的项目。雨水和大气冷凝水具有较大的水溶性，是研究H2O2的合适介质。例如，过氧化氢通常以微摩尔浓度存在于雨水中。它可以在下雨的几个小时内保持稳定，这使得这个实验室非常适合这个项目，因为它靠近收集点和分析实验室。北卡罗莱纳州的一个地点有大约十年的雨水成分数据。这种相对较长的数据记录将有助于解释新的测量数据，也将有助于与其他采样地点进行比较。＊＊＊