Abstract

Refuse disposal (e.g., landfilling and incineration) have been recognized as a significant anthropogenic source of mercury (Hg-0) emission globally. However, in-situ measurements of Hg emission from landfill or refuse dumping sites where fugitive spontaneous combustion occurs have not been reported. Gaseous elemental mercury (Hg-0) concentration and emission flux were observed near spontaneous combustions of refuse at a landfill site in southwestern China. Ambient Hg concentrations above the refuse surface ranged from 42.7 +/- 20.0 to 396.4 +/- 114.2 ng m(3), up to 10 times enhancement due to the spontaneous burning. Using a box model with Hg data obtained from 2004 to 2013, we estimated that the Hg emission from refuse was amplified by 8-40 times due to spontaneous combustion. A micrometeorological flux measurement system based on relaxed eddy accumulation was configured downwind of the combustion sites to quantify the Hg emission. Extremely large turbulent deposition fluxes (up to 128.6 gg m(-2) h(-1), 20 min average) were detected during periods of high Hg concentration events over the measurement footprint. The effect of temperature, moisture and light on the air surface exchange of Hg exchange was found to be masked by the overwhelming deposition of Hg from the enriched air from the refuse combustion plumes. This research reveals that mercury emission from the landfill refuse can be boosted by fugitive spontaneous combustion of refuse. The emission represents an anthropogenic source that has been overlooked in Hg inventory estimates. (C) 2013 Elsevier Ltd. All rights reserved.

Keywords

Mercury flux; Refuse; Spontaneous combustion; Relaxed eddy accumulation; Box modeling

Published in

Atmospheric Environment
2013, Volume: 79, pages: 540-545
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

UKÄ Subject classification

Geochemistry


Publication identifier

DOI: https://doi.org/10.1016/j.atmosenv.2013.07.016

Permanent link to this page (URI)

https://res.slu.se/id/publ/86078