Concentration and speciation of mercury in atmospheric particulates in the Wuda coal fire area, Inner Mongolia, China.

Yahui Qian,Zhe Wang,Handong Liang,Yunyun Shi,Qingyi Cao,Yanci Liang

doi:10.1007/s11356-021-15805-2

Abstract

Coal-seam fire is a source of atmospheric mercury that is difficult to control. The Wuda Coalfield in Inner Mongolia, China, is one of the most severe coal fire disaster areas worldwide and has been burning for more than 50 years. To investigate atmospheric mercury pollution from the Wuda coal fire, gaseous elemental mercury (GEM) concentrations and atmospheric particulate mercury (PHg) speciation were measured using a RA-915+ mercury analyzer and the temperature-programmed desorption method. Near-surface GEM concentrations in the Wuda Coalfield and adjacent urban area were 80 ng m-3 (65-90 ng m-3) and 52 ng m-3 (25-95 ng m-3), respectively, which are far higher than the local background value (22 ng m-3). PHg concentrations in the coalfield and urban area also reached significantly high levels, 33 ng m-3 (25-45 ng m-3) and 22 ng m-3 (14-29 ng m-3), respectively (p < 0.05). There is no clear evidence that PHg combines with organic carbon or elemental carbon, but PHg concentration appears to be controlled by air acidity. PHg mainly exists in inorganic forms, such as HgCl2, HgS, HgO, and Hg(NO3)2·H2O. This work can provide references for the speciation analysis of atmospheric PHg and the safety assessment of environmental mercury.

Highlights

Coal fires are a global catastrophe and have been reported in many countries and regions, such as the United States, Australia, South Africa, India, and China (Heffern and Coates, 2004; Kuenzer and Stracher, 2012; Mishra et al, 2011; Pone et al, 2007; Sharygin et al, 2009; Zhang et al, 2004)
There is no clear evidence that PHg combines with organic carbon (OC) or elemental carbon (EC), but PHg concentration appears to be controlled by air acidity
This study examined the concentration and speciation of PHg in the Wuda Coalfield fire area using a variety of experimental data

Summary

Introduction

Coal fires are a global catastrophe and have been reported in many countries and regions, such as the United States, Australia, South Africa, India, and China (Heffern and Coates, 2004; Kuenzer and Stracher, 2012; Mishra et al, 2011; Pone et al, 2007; Sharygin et al, 2009; Zhang et al, 2004). Dust fall, and air mercury pollution caused by coal fires have attracted significant attention from the research community (Liang et al, 2014; Liang et al, 2016; Liang et al, 2018; Li et al, 2018). No effective measures are in place to curb coal fire pollution

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