Measure-Specific Effectiveness of Air Pollution Control on China’s Atmospheric Mercury Concentration and Deposition during 2013–2017

Abstract

China took aggressive air pollution control measures from 2013 to 2017, leading to the mitigation of atmospheric mercury pollution as a cobenefit. This study is the first to systematically evaluate the effect of five major air pollution control measures in reducing mercury emissions, the total gaseous mercury (TGM) concentration and mercury deposition flux (FLX) for unit emissions reduction. From 2013 to 2017, China’s mercury emissions decreased from 571 to 444 tons, resulting in a 0.29 ng m–3 decrease in the TGM concentration, on average, and in a 17 μg m–2 yr–1 decrease in FLX. Ultralow emission renovations of coal-fired power plants are identified as the most effective emission abatement measure. As a result of this successful measure, coal-fired power plants are no longer the main mercury emitters. In 2017, the cement clinker sector became the largest emitter due to the use of less effective mercury removal measures. However, in terms of the mitigated TGM concentration and FLX levels per unit emission abatement, newly built wet flue gas desulfurization (WFGD) systems in coal-fired industrial boilers have become particularly effective in decreasing FLX levels. Therefore, to effectively reduce atmospheric mercury pollution in China, prioritizing mercury emissions control of cement clinkers and coal-fired industrial boilers is recommended.

The Effect of Air Pollution and Temperature on Pulmonary Function in Healthy People in Xi’an, China

“…Air pollution has become a major threat of public health worldwide, causing up to 7 million premature deaths annually [16,17]. In recent years, the developing countries in Asia, such as India and China, have begun large-scale industrialization of urbanization process, so they have been struggling with serious air pollution [18][19][20]. Besides, Xi'an is located in the lowest part of Guanzhong Basin, which makes it di cult for pollutants to be discharged, just like a "garbage bags" [21,22].…”

How Green Transition of Energy System Impacts China's Mercury Emissions

“…These pollution control mandates (e.g., Emission Standard of Air Pollutants for Thermal Power Plants [GB13223‐2011]) have brought administrative strong incentives to measures such as expanding APCDs installation in coal‐fired power plants. For example, selective catalytic reduction is widely applied in pulverized coal boilers, and 65% of APCDs are equipped to meet the ultra‐low emission standard (Liu et al, ), both of which are able to largely remove the atmospheric mercury emissions from per unit coal burned. Thanks to the growing number of installed air pollution control devices in coal‐fired power plants, mercury emission factors of key coal‐dominated industries experienced obvious decline in most provincial regions during 2012–2017 (Table S4).…”

“…For mercury emission inventory, this study uses Monte Carlo simulations to generate the probabilistic emissions by taking into account the probability distribution of key parameters, including activity level, mercury content in coal, and APCD combination removal efficiencies (Wu et al, , ). A normal distribution with a coefficient of variation is set to be 5% for energy consumption data (Liu et al, ), while mercury content of consumed coal is assumed to fit a log‐normal distribution curve (Wu et al, ; Zhang et al, ). In terms of APCD removal efficiencies, different types of APCD combinations are considered to fit normal distribution or Weibull distribution, and the average and coefficient of variation are collected from previous studies (Liu et al, , ; Wu et al, ; Zhang et al, ).…”

“…A normal distribution with a coefficient of variation is set to be 5% for energy consumption data (Liu et al, ), while mercury content of consumed coal is assumed to fit a log‐normal distribution curve (Wu et al, ; Zhang et al, ). In terms of APCD removal efficiencies, different types of APCD combinations are considered to fit normal distribution or Weibull distribution, and the average and coefficient of variation are collected from previous studies (Liu et al, , ; Wu et al, ; Zhang et al, ). To acquire the reliable statistic distribution results, we set the sampling number as 10,000.…”

“…Therefore, we update the emission factor of coal‐fired power plants and coal‐fired industrial boiler at provincial level in 2017 by referring to China Atmospheric Mercury Emission model (Zhang et al, ; details in Text S3). The provincial APCD installation rate of different type in 2017 is derived from the latest study (Liu et al, ). Other parameters such as provincial mercury content in consumed coal, mercury release rate of a certain type of boiler, removal efficiency of coal washing, and removal efficiency of a certain type of APCD combination are obtained based on various previous studies (Liu et al, ; Wu et al, ; Zhang et al, ).…”