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

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.

Mercury in Municipal Solid Waste in China and Its Control: A Review

“…Pollution of topsoils surrounding landfill sites also occurred, probably from deposition of mercury in the landfill gas. 39,40,42 3.2. Composting.…”

“…62,81 Maximum mercury emissions occurred at the working face, which decreased significantly after being covered by soil or vegetation, while the vent pipes appeared to be the least significant mercury emission sources. 40 Overall, methylated mercury species accounted for <5% of the total mercury in the landfill gas, 40 but posed a significant concern because of their extreme toxicity. Pollution of topsoils surrounding landfill sites also occurred, probably from deposition of mercury in the landfill gas.…”

Synthesis of current data for Hg in areas of geologic resource extraction contamination and aquatic systems in China

“…The data compared favourably with surveys conducted in other countries, such as that of Alachua landfill in California, USA where MSW contained 0.033-17 mg total-Hg kg − 1 (Earle et al, 1999). In the study of Li et al (2010b) including five landfills from the inland cities of Guiyang and Wuhan, the mean total-Hg concentration in MSW varied for the individual sites between 0.20 and 1.9 mg kg ) from the other investigated landfills (Tang et al, 2003;Li et al, 2010b). Total-Hg, gaseous Hg, and matrix combined Hg concentrations in topsoil of the Laogang landfill, Shanghai were found to be significantly positively correlated with each other, but no correlation between Hg concentrations and filling periods was obtained( Fig.…”

“…As landfill gases in China are rarely utilised or promptly flared, there is an ecological risk associated with a direct release of highly toxic dimethyl Hg and MMHg species from landfills. Li et al (2010b) investigated Hg emissions from landfills in Guiyang using DFC technique. GEM concentrations in ambient air ranged between 1.6 and 474 ng m In the future, it is inevitable that more and more incineration facilities will be constructed in China to dispose of MSW instead of landfills.…”

Mercury risk from fluorescent lamps in China: Current status and future perspective

“…However, leachate collection and treatment systems were not installed in over half of the existing landfills (MOC, 2006;Yan and Wu, 2003), and most landfills do not have gas collection systems (Huang and He, 2008). The mercury in fluorescent lamps buried in landfills can be released into the surrounding environment through leachate leakage and landfill gas emissions (Li et al, 2005(Li et al, , 2010. Similarly, the mercury in fluorescent lamps will inevitably end up in the final compost product in the absence of rigorous separation and recycling during MSW composting.…”