Total gaseous mercury emissions from soil in Guiyang, Guizhou, China

Abstract

Guiyang is located in the Circum‐Pacific Global Mercuriferous Belt, and mercury concentrations in soil in this area are enriched. In situ total gaseous mercury (TGM) exchange fluxes between air and soil surface were intensively measured at four sampling sites in Guiyang from 21 May to 16 June 2003. Overall, net emissions were obtained from all sampling sites. Soil mercury concentration and solar radiation are proved to be the two most important parameters to control mercury emissions from soil. Meanwhile, a rain event can enhance mercury emission rate significantly. A simple model based on the linear correlation between mercury flux and solar radiation was applied to scale up mercury emissions from soil zones with different mercury concentration ranges. It is observed that mercury emission fluxes from soil in Guiyang are one order of magnitude higher than the value used in early models to represent emissions from global mercuriferous belts which is 1.1 ng m−2 h−1. The annual mercury emission from soil in Guiyang is calculated to be 408 kg, which highlights that natural emissions from soil contribute significantly to the elevated TGM concentrations in the ambient air in Guiyang.

A laboratory based experimental study of mercury emission from contaminated soils in the River Idrijca catchment

“…In recent years, considerable progress in understanding mercury geochemistry at such sites has been made with the development of interfacial mercury flux measurement technology (Ferrara et al, 1998a;Ferrara et al, 1998b;Gustin et al, 1996;Nacht et al, 2004;Gustin, 2003;Engle et al, 2001). Mercury emission rates from these Hg-enriched areas were found to be greater than previously estimated, indicating that these sources may be more significant contributors of mercury to the atmosphere than previously realized (Gustin et al, 2000;Gustin, 2003;Engle et al, 2001;Wang et al, 2005, Wang et al, 2007a, Wang et al, 2007bCoolbaugh et al, 2002;Feng et al, 2005). However, estimations of the quantitative significance of Hg emission relative to other pathways are very uncertain and too little is known about the amounts and species of mercury emitting from soil as well as factors causing and affecting this process (Schlüter, 2000), especially at contaminated sites.…”

Estimating mercury emission outflow from East Asia using CMAQ-Hg

“…Therefore, the model-predicted values were comparatively lower because of the focus of regional assessment in this study. The uncertainties of mercury emissions, which have been thought to be underestimated or miss certain emission sources (Pan et al, 2006;Weiss-Penzias et al, 2007;Friedli et al, 2004;Feng et al, 2004aFeng et al, , 2005, might also be important reasons for the under-prediction of GEM. Model predictions of RGM and PHg agreed reasonably well with the observations made in China, but over-predicted those observed in South Korea and at Cape Hedo, Japan (Table 2).…”

A whole-air relaxed eddy accumulation measurement system for sampling vertical vapour exchange of elemental mercury

“…Up until now in China, solely flowthrough dynamic flux chambers (DFCs) covering a small plot of 50.1 m 2 have been employed for such studies (e.g. Feng et al, 2004Feng et al, , 2005Wang et al, 2005Wang et al, , 2006Wang et al, , 2007aWang et al, , 2007bFu et al, 2008Fu et al, , 2012aFu et al, , 2012bZhu et al, 2011;Zhu et al, 2013). Enclosure methods are of relatively low cost, easy to operate and straightforward.…”