有机薄膜上硝酸的光化学损失：一种可能的氮氧化物循环机制

Photochemical loss of nitric acid on organic films: a possible recycling mechanism for NO(x).

作者信息

Handley Susannah R, Clifford Daniel, Donaldson D J

机构信息

Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.

出版信息

Environ Sci Technol. 2007 Jun 1;41(11):3898-903. doi: 10.1021/es062044z.

DOI:10.1021/es062044z

PMID:17612166

Abstract

The films coating urban impervious surfaces have been found to be comprised of about 7% inorganic nitrate and approximately 10% organic compounds (by mass). A simple steady-state analysis of the lifetime of the nitrate in the film suggests the existence of a loss process(es) in addition to washout by rainfall. We show here that gas-phase nitric acid can be taken up in organic films and lower the film pH. Photolysis of nitrated films using actinic illumination causes loss both of protons and of nitrate anion. We argue that this is possibly due to a combination of direct and indirect (photosensitized) photochemistry involving nitrate ions, yielding gas-phase HONO and/or NO2.

摘要

已发现覆盖城市不透水表面的薄膜约由7%的无机硝酸盐和大约10%的有机化合物（按质量计）组成。对薄膜中硝酸盐寿命的简单稳态分析表明，除了降雨冲刷外，还存在其他损失过程。我们在此表明，气相硝酸可被有机薄膜吸收并降低薄膜的pH值。使用光化辐射对硝化薄膜进行光解会导致质子和硝酸根阴离子的损失。我们认为，这可能是由于涉及硝酸根离子的直接和间接（光敏）光化学作用共同导致的，产生气相亚硝酸和/或二氧化氮。