Department of Chemistry, University of Iowa, Iowa City IA 52242, USA.
Proc Natl Acad Sci U S A. 2010 Apr 13;107(15):6628-33. doi: 10.1073/pnas.0910809107. Epub 2010 Apr 1.
A number of recent studies have shown that iron dissolution in Fe-containing dust aerosol can be linked to source material (mineral or anthropogenic), mineralogy, and iron speciation. All of these factors need to be incorporated into atmospheric chemistry models if these models are to accurately predict the impact of Fe-containing dusts into open ocean waters. In this report, we combine dissolution measurements along with spectroscopy and microscopy to focus on nanoscale size effects in the dissolution of Fe-containing minerals in low-pH environments and the importance of acid type, including HNO(3), H(2)SO(4), and HCl, on dissolution. All of these acids are present in the atmosphere, and dust particles have been shown to be associated with nitrate, sulfate, and/or chloride. These measurements are done under light and dark conditions so as to simulate and distinguish between daytime and nighttime atmospheric chemical processing. Both size (nano- versus micron-sized particles) and anion (nitrate, sulfate, and chloride) are found to play significant roles in the dissolution of alpha-FeOOH under both light and dark conditions. The current study highlights these important, yet unconsidered, factors in the atmospheric processing of iron-containing mineral dust aerosol.
一些最近的研究表明，含铁粉尘气溶胶中的铁溶解与源材料（矿物或人为）、矿物学和铁形态有关。如果这些模型要准确预测含铁粉尘对开阔海域的影响，那么所有这些因素都需要纳入大气化学模型中。在本报告中，我们结合溶解测量以及光谱和显微镜技术，重点研究了在低 pH 环境中含铁矿物溶解的纳米级尺寸效应，以及酸类型（包括 HNO3、H2SO4 和 HCl）对溶解的重要性。所有这些酸都存在于大气中，并且已经表明粉尘颗粒与硝酸盐、硫酸盐和/或氯化物有关。这些测量是在光照和黑暗条件下进行的，以便模拟和区分白天和夜间的大气化学过程。在光照和黑暗条件下，尺寸（纳米级与微米级颗粒）和阴离子（硝酸盐、硫酸盐和氯化物）都被发现对 α-FeOOH 的溶解起着重要作用。本研究强调了这些在含铁矿物粉尘气溶胶大气处理中重要但未被考虑的因素。
