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Mercury in Arctic snow: Quantifying the kinetics of photochemical oxidation and reduction
- Source :
- Science of The Total Environment. :115-132
- Publication Year :
- 2015
- Publisher :
- Elsevier BV, 2015.
-
Abstract
- Controlled experiments were performed with frozen and melted Arctic snow to quantify relationships between mercury photoreaction kinetics, ultra violet (UV) radiation intensity, and snow ion concentrations. Frozen (-10°C) and melted (4°C) snow samples from three Arctic sites were exposed to UV (280-400 nm) radiation (1.26-5.78 W · m(-2)), and a parabolic relationship was found between reduction rate constants in frozen and melted snow with increasing UV intensity. Total photoreduced mercury in frozen and melted snow increased linearly with greater UV intensity. Snow with the highest concentrations of chloride and iron had larger photoreduction and photooxidation rate constants, while also having the lowest Hg(0) production. Our results indicate that the amount of mercury photoreduction (loss from snow) is the highest at high UV radiation intensities, while the fastest rates of mercury photoreduction occurred at both low and high intensities. This suggests that, assuming all else is equal, earlier Arctic snow melt periods (when UV intensities are less intense) may result in less mercury loss to the atmosphere by photoreduction and flux, since less Hg(0) is photoproduced at lower UV intensities, thereby resulting in potentially greater mercury transport to aquatic systems with snowmelt.
- Subjects :
- Environmental Engineering
010504 meteorology & atmospheric sciences
Chemistry
Kinetics
Analytical chemistry
chemistry.chemical_element
010501 environmental sciences
Atmospheric sciences
Snow
01 natural sciences
Pollution
Chloride
Ion
Mercury (element)
Reaction rate constant
Arctic
13. Climate action
Snowmelt
medicine
Environmental Chemistry
human activities
Waste Management and Disposal
0105 earth and related environmental sciences
medicine.drug
Subjects
Details
- ISSN :
- 00489697
- Database :
- OpenAIRE
- Journal :
- Science of The Total Environment
- Accession number :
- edsair.doi.dedup.....1946b01e3dd72330da0daf622ea13437