气候变化领域集成服务门户(CCPortal): Diel variation in mercury stable isotope ratios records photoreduction of PM2.5-bound mercury

CCPortal

DOI	10.5194/acp-19-315-2019
	Diel variation in mercury stable isotope ratios records photoreduction of PM2.5-bound mercury
	Huang Q.; Chen J.; Huang W.; Reinfelder J.R.; Fu P.; Yuan S.; Wang Z.; Yuan W.; Cai H.; Ren H.; Sun Y.; He L.
发表日期	2019
ISSN	16807316
起始页码	315
结束页码	325
卷号	19 期号:1
英文摘要	Mercury (Hg) bound to fine aerosols (PM 2.5 -Hg) may undergo photochemical reaction that causes isotopic fractionation and obscures the initial isotopic signatures. In this study, we quantified Hg isotopic compositions for 56 PM 2.5 samples collected between 15 September and 16 October 2015 from Beijing, China, among which 26 were collected during daytime (between 08:00 and 18:30 LT) and 30 during night (between 19:00 and 07:30 LT). The results show that diel variation was statistically significant (p< 0.05) for Hg content, δ199Hg and δ200Hg, with Hg content during daytime (0.32±0.14 μg g -1 ) lower than at night (0.48±0.24 μg g -1 ) and δ199Hg and δ200Hg values during daytime (mean of 0.26 ±0.40 and 0.09 ±0.06, respectively) higher than during nighttime (0.04 ±0.22 and 0.06 ±0.05, respectively), whereas PM 2.5 concentrations and δ202Hg values showed insignificant (p< >< 0.05) diel variation. Geochemical characteristics of the samples and the air mass backward trajectories (PM 2.5 source related) suggest that diel variation in δ199Hg values resulted primarily from the photochemical reduction of divalent PM 2.5 -Hg, rather than variations in emission sources. The importance of photoreduction is supported by the strong correlations between δ199Hg and (i) δ201Hg (positive, slope Combining double low line 1.1), (ii) δ202Hg (positive, slope Combining double low line 1.15), (iii) content of Hg in PM 2.5 (negative), (iv) sunshine durations (positive) and (v) ozone concentration (positive) observed for consecutive day-night paired samples. Our results provide isotopic evidence that local, daily photochemical reduction of divalent Hg is of critical importance to the fate of PM 2.5 -Hg in urban atmospheres and that, in addition to variation in sources, photochemical reduction appears to be an important process that affects both the particle mass-specific abundance and isotopic composition of PM 2.5 -Hg. © 2019 Author(s).
语种	英语
scopus关键词	diel variation; isotopic composition; isotopic ratio; mercury (element); particulate matter; reduction; stable isotope; Beijing [China]; China
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144733
作者单位	State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, CAS, Guiyang, 550081, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, CAS, Guangzhou, 510640, China; Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China; Department of Environmental Sciences, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, United States; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, CAS, Beijing, 100029, China; Laboratory of Hebei Institute of Regional Geology and Mineral Resources Survey, Shijiazhuang, 065000, China
推荐引用方式 GB/T 7714	Huang Q.,Chen J.,Huang W.,et al. Diel variation in mercury stable isotope ratios records photoreduction of PM2.5-bound mercury[J],2019,19(1).
APA	Huang Q..,Chen J..,Huang W..,Reinfelder J.R..,Fu P..,...&He L..(2019).Diel variation in mercury stable isotope ratios records photoreduction of PM2.5-bound mercury.Atmospheric Chemistry and Physics,19(1).
MLA	Huang Q.,et al."Diel variation in mercury stable isotope ratios records photoreduction of PM2.5-bound mercury".Atmospheric Chemistry and Physics 19.1(2019).