Emissions of air-borne mercury from five municipal solid waste landfills in Guiyang and Wuhan, China

Z.-G Li,L.-H Shang,S.-L Tang,P Li,S.-F Wang,G.-L Qiu,X Feng,L Liang,X.-W Fu

doi:10.5194/acp-10-3353-2010

Abstract

Abstract. China disposes of bulk Municipal Solid Waste (MSW) by landfilling, resulting in a large quantity of mercury that enters landfills through waste. A detailed study on atmospheric mercury emissions from MSW landfills in China is necessary to understand mercury behavior from this source. Between 2003 and 2006, mercury airborne emissions through different pathways, as well as mercury speciation in Landfill Gas (LFG) were measured at 5 MSW landfills in Guiyang and Wuhan, China. The results showed that mercury content in the substrate increased the magnitude of mercury emissions, with the highest emission rate measured at the working face and in uncovered waste areas, and the lowest measured near soil covers and vegetated areas. Meteorological parameters, especially solar radiation, influenced the diurnal pattern of mercury surface-air emissions. Total Gaseous Mercury (TGM) in LFG varied from 2.0 to 1406.0 ng m−3, Monomethyl Mercury (MMHg) and Dimethyl Mercury (DMHg) in LFG averaged at 1.93 and 9.21 ng m−3, and accounted for 0.51% and 1.79% of the TGM in the LFG, respectively. Total mercury emitted from the five landfills ranged from 17 to 3300 g yr−1, with the highest from the working face, then soil covering, and finally the vent pipes.

Highlights

Mercury (Hg) emissions from Municipal Solid Waste (MSW) incineration are regarded as one of the most important anthropogenic mercury sources to the atmosphere (US EPA, 1997; van Velzen et al, 2002)
In this paper we report the results of mercury emissions from 5 MSW landfills in Guiyang and Wuhan city, China, sampled between 2003 and 2006
A few cover soil samples in D-Z-W landfill contained high Hg (3.124–6.527 mg kg−1), which may be due to unauthorized dumping of MSW that occurred at this landfill after its closure

Summary

Introduction

Mercury (Hg) emissions from Municipal Solid Waste (MSW) incineration are regarded as one of the most important anthropogenic mercury sources to the atmosphere (US EPA, 1997; van Velzen et al, 2002). China is one of the largest MSW producers in the world, generating over 150 million tonnes MSW per year, which accounts for 29% of the global total. Landfill is the main disposal method for MSW in China, treating 68.9 million tonnes at 444 landfills in 2004, accounting for 85.4% of the total amount of treated waste (including landfill, incineration and compost, the rest was not treated properly, Huang et al, 2006; Liu et al, 2007). Mercury enters the landfill mainly through mercury-containing waste, such as batteries, fluorescent lamps and thermometers (US EPA, 1992). Hg content in batteries was lowered since 2001, 153 tonnes of Hg were still used

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Conclusion