scholarly journals A Laboratory Study on the Isotopic Composition of Hg(0) Emitted From Hg‐Enriched Soils in Wanshan Hg Mining Area

2020 ◽  
Vol 125 (19) ◽  
Author(s):  
Hui Zhang ◽  
Qingyou Tan ◽  
Leiming Zhang ◽  
Xuewu Fu ◽  
Xinbin Feng
Keyword(s):  
Isotopic Composition ◽  
Laboratory Study ◽  
Mining Area ◽  
Hg Mining

Mercury methylation in rice paddies and its possible controlling factors in the Hg mining area, Guizhou province, Southwest China

2016 ◽  
Vol 215 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Zhao ◽  
Guangle Qiu ◽  
Christopher W.N. Anderson ◽  
Bo Meng ◽  
Dingyong Wang ◽  
...  
Keyword(s):  
Southwest China ◽  
Mining Area ◽  
Controlling Factors ◽  
Guizhou Province ◽  
Mercury Methylation ◽  
Rice Paddies ◽  
Hg Mining

Mercury isotope fractionation during the exchange of Hg between the atmosphere and land surfaces: implications for atmospheric Hg cycles

2020 ◽  
Author(s):  
Wei Zhu ◽  
Xuewu Fu ◽  
Hui Zhang ◽  
Chen Liu ◽  
Ben Yu ◽  
...  
Keyword(s):  
Land Surface ◽  
Isotope Fractionation ◽  
Agricultural Soils ◽  
Mining Area ◽  
Balance Model ◽  
Flux Chamber ◽  
Biogeochemical Models ◽  
Mass Dependent Fractionation ◽  
Hg Mining ◽  
Soil Hg

<p>Mercury (Hg) is a neurotoxic pollutant distributed globally via atmospheric transportation of elemental Hg (Hg(0)). Both anthropogenic and natural processes emit Hg to the atmosphere, where the later contributes up to approximately two thirds of the total emissions. Hg(II) in the Earth’s surface can be reduced chemically and biologically, resulted subsequent re-emission of Hg(0) back to the atmosphere. The Hg(0) exhibits bi-directional exchange (i.e., deposition and/or emission) between the land surface and atmosphere. Soil is the largest terrestrial Hg reservoir and its interaction with the atmosphere influences the atmospheric Hg cycling largely. Hg(0) emission from the terrestrial surfaces soil has been postulated to carry a negative MDF and positive MIF in the global Hg biogeochemical models. However, to date, no experimental evidence support that the complex terrestrial soil Hg(0) emission in accordance with this hypothetical simplification.</p><p>We coupled the <em>in-situ</em> Hg(0) dynamic flux chamber measurement and stable Hg isotope analysis to report a first dataset on the Hg isotope fractionation during the exchange of Hg(0) between the atmosphere and  8 soils and 1 cinnabar surfaces. The effect of air-soil/cinnabar exchange shifted Hg(0) concentrations in the flux chamber [i.e., (Hg(0)<sub>chamber</sub>-Hg(0)<sub>ambient</sub>)/Hg(0)<sub>chamber</sub>] by a factor of -0.29 – 0.90, corresponding to Hg(0) exchange fluxes ranging from -773 – 14457 ng m<sup>-2</sup> h<sup>-1</sup>. Our results showed that the exchange of Hg(0) between the atmosphere and soil/cinnabar could lead to an enrichment of both light and heavy isotopes (δ<sup>202</sup>Hg signatures) in Hg(0), as well as depletion or enrichment of odd isotopes (Δ<sup>199</sup>Hg signatures). This highlighted that multiple processes controlled the land-atmosphere exchange of Hg(0) and affected Hg isotope fractionation. Using a conservative isotope mass balance model, we found urban soils Hg(0) emission exhibited large variations in both δ<sup>202</sup>Hg (-3.04 to -0.34‰) and Δ<sup>199</sup>Hg (-0.60 to 0.38‰), which might be controlled by the Hg isotopic signatures in soils and environmental factors. The isotope signatures of Hg(0) emitted from agricultural background soils (δ<sup>202</sup>Hg = -1.31 ± 1.09‰, Δ<sup>199</sup>Hg = -0.26 ± 0.16‰, 1σ, n=15) and Hg-enriched agricultural soils in Hg mining area (δ<sup>202</sup>Hg = 0.51 ± 1.09‰, Δ<sup>199</sup>Hg = -0.10 ± 0.11‰, 1σ, n=12) exhibited contrasting mass dependent fractionation (MDF). Photo-reduction of soil Hg(II) coordinated to sulfurless ligands likely dominated the MIF of Hg isotope during the exchange of Hg between the atmosphere and  both urban and agricultural soils. While the positive shift of δ<sup>202</sup>Hg in mining area suggested that other processes including sorption and oxidation were also important in controlling MDF of Hg isotope during air/soil exchange. In a line with Hg-enriched agricultural soils, the forest soil emitted Hg(0) in Hg mining area enriched in heavy isotopes relative to the soil but depleted in odd isotopes. Hg(0) emission from cinnabar ore waste exhibited significant negative δ<sup>202</sup>Hg (-2.21 to -1.67‰) but positive Δ<sup>199</sup>Hg (0.17 to 0.38‰). Our results demonstrate complex Hg isotope fractionation during air-soil/cinnabar Hg(0) exchange resulted contrasting enrichment or depletion effects on the atmospheric Hg isotope compositions, thus have important implications for understanding the atmospheric Hg isotope signatures and modeling the global Hg cycling.</p>

Assessing anthropogenic sources of mercury in soil in Wanshan Hg mining area, Guizhou, China

2013 ◽  
Vol 20 (11) ◽  
pp. 7560-7569 ◽  
Author(s):  
Zhihui Dai ◽  
Xinbin Feng ◽  
Chao Zhang ◽  
Jingfu Wang ◽  
Taiming Jiang ◽  
...  
Keyword(s):  
Mining Area ◽  
Anthropogenic Sources ◽  
Hg Mining

scholarly journals Spatial distribution of mercury deposition fluxes in Wanshan Hg mining area, Guizhou province, China

2012 ◽  
Vol 12 (14) ◽  
pp. 6207-6218 ◽  
Author(s):  
Z. H. Dai ◽  
X. B. Feng ◽  
J. Sommar ◽  
P. Li ◽  
X. W. Fu
Keyword(s):  
Spatial Distribution ◽  
Dry Deposition ◽  
Wet Deposition ◽  
Ambient Air ◽  
Mining Area ◽  
Atmospheric Mercury ◽  
Guizhou Province ◽  
Mining Activities ◽  
Deposition Fluxes ◽  
Hg Mining

Abstract. The legacy of long-term mining activities in Wanshan mercury (Hg) mining area (WMMA), Guizhou, China including a series of environmental issues related to Hg pollution. The spatial distribution of gaseous elemental mercury (Hg0) concentrations in ambient air were monitored using a mobile RA-915+ Zeeman Mercury Analyzer during daytime and night time in May 2010. The data imply that calcines and mine wastes piles located at Dashuixi and on-going artisanal Hg mining activities at Supeng were major sources of atmospheric mercury in WMMA. For a full year (May 2010 to May 2011), sampling of precipitation and throughfall were conducted on a weekly basis at three sites (Shenchong, Dashuixi, and Supeng) within WMMA. Hg in deposition was characterized by analysis of total Hg (THg) and dissolved Hg (DHg) concentrations. The corresponding data exhibit a high degree of variability, both temporarily and spatially. The volume-weighted mean THg concentrations in precipitation and throughfall samples were 502.6 ng l−1 and 977.8 ng l−1 at Shenchong, 814.1 ng l−1and 3392.1 ng l−1 at Dashuixi, 7490.1 ng l−1and 9641.5 ng l−1 at Supeng, respectively. THg was enhanced in throughfall compared to wet deposition samples by up to a factor of 7. The annual wet Hg deposition fluxes were 29.1, 68.8 and 593.1 μg m−2 yr−1 at Shenchong, Dashuixi and Supeng, respectively, while the annual dry Hg deposition fluxes were estimated to be 378.9, 2613.6 and 6178 μg m−2 yr−1 at these sites, respectively. Dry deposition played a dominant role in total atmospheric Hg deposition in WMMA since the dry deposition fluxes were 10.4–37.9 times higher than the wet deposition fluxes during the whole sample period. Our data showed that air deposition was still an important pathway of Hg contamination to the local environment in WMMA.

scholarly journals Spatial distribution of mercury deposition fluxes in Wanshan Hg mining area, Guizhou, China

2012 ◽  
Vol 12 (2) ◽  
pp. 5739-5769 ◽  
Author(s):  
Z. H. Dai ◽  
X. B. Feng ◽  
X. W. Fu ◽  
P. Li
Keyword(s):  
Spatial Distribution ◽  
Dry Deposition ◽  
Dominant Role ◽  
Ambient Air ◽  
Mining Area ◽  
Atmospheric Mercury ◽  
Mercury Deposition ◽  
Night Time ◽  
Deposition Fluxes ◽  
Hg Mining

Abstract. A long-term mining history introduced a series of environmental problems in Wanshan Hg mining area, Guizhou, China. The spatial distribution of gaseous elemental Hg (Hg0) concentrations in ambient air were investigated using RA-915+ Zeeman Mercury Analyzer during day time and night time in May 2010, which showed that calcines and mine wastes piles located at Dashuixi and on-going artisanal Hg mining activities at Supeng were major sources of atmospheric mercury in Wanshan Hg mining area. Meanwhile, both precipitation and throughfall samples were collected weekly at Shenchong, Dashuixi, and Supeng from May 2010 to May 2011, respectively. Our data showed that the concentrations of different Hg species varied with a large range, and the annual volume-weighted mean total mercury (THg) concentrations in precipitation and throughfall samples were 502.6 ng L−1 and 977.8 ng L−1 at Shenchong, 814.1 ng L−1and 3392.1 ng L−1 at Dashuixi, 7490.1 ng L−1 and 9641.5 ng L−1 at Supeng, respectively. Besides, THg concentrations in all throughfall samples were 1–7 folds higher than those in precipitation samples. The annual wet Hg deposition fluxes were 29.1, 68.8 and 593.1 μg m−2 yr−1 at Shenchong, Dashuixi and Supeng, respectively, while the annual dry Hg deposition fluxes were estimated to be 378.9, 2613.6 and 6178 μg m−2 yr−1 at these sites, respectively. Dry deposition played a dominant role in total atmospheric Hg deposition in Wanshan Hg mining area since the dry deposition fluxes were 10.4–37.9 times higher than the wet deposition fluxes during the whole sample period. Our data showed that air deposition was still an important pathway of Hg contamination to the local environment in Wanshan Hg mining area.

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