Atmospheric Mercury Emissions Research Articles

New insight into atmospheric mercury emissions from zinc smelters using mass flow analysis.

The mercury (Hg) flow paths from three zinc (Zn) smelters indicated that a large quantity of Hg, approximately 38.0-57.0% of the total Hg input, was stored as acid slag in the landfill sites. Approximately 15.0-27.1% of the Hg input was emitted into water or stored as open-dumped slags, and 3.3-14.5% of the Hg input ended in sulfuric acid. Atmospheric Hg emissions, accounting for 1.4-9.6% of the total Hg input, were from both the Zn production and waste disposal processes. Atmospheric Hg emissions from the waste disposal processes accounted for 40.6, 89.6, and 94.6% of the total atmospheric Hg emissions of the three studied smelters, respectively. The Zn production process mainly contributed to oxidized Hg (Hg2+) emissions, whereas the waste disposal process generated mostly elemental Hg (Hg0) emissions. When the emissions from these two processes are considered together, the emission proportion of the Hg2+ mass was 51, 46, and 29% in smelters A, B, and C, respectively. These results indicated that approximately 10.8±5.8 t of atmospheric Hg emissions from the waste disposal process were ignored in recent inventories. Therefore, the total atmospheric Hg emissions from the Zn industry of China should be approximately 50 t.

Updated emission inventories for speciated atmospheric mercury from anthropogenic sources in China.

China is the largest contributor to global atmospheric mercury (Hg), and accurate emission inventories in China are needed to reduce large gaps existing in global Hg mass balance estimates and assess Hg effects on various ecosystems. The China Atmospheric Mercury Emission (CAME) model was developed in this study using probabilistic emission factors generated from abundant on-site measurements and literature data. Using this model, total anthropogenic Hg emissions were estimated to be continuously increasing from 356 t in 2000 to 538 t in 2010 with an average annual increase rate of 4.2%. Industrial coal combustion, coal-fired power plants, nonferrous metal smelting, and cement production were identified to be the dominant Hg emission sources in China. The ten largest contributing provinces accounted for nearly 60% of the total Hg emissions in 2010. Speciated Hg emission inventory was developed over China with a grid-resolution of 36 × 36 km, providing needed emission fields for Hg transport models. In this new inventory, the sectoral Hg speciation profiles were significantly improved based on the latest data from field measurements and more detailed technology categorization. The overall uncertainties of the newly developed inventory were estimated to be in the range of -20% to +23%.

Increase in mercury in Pacific yellowfin tuna.

Mercury is a toxic trace metal that can accumulate to levels that threaten human and environmental health. Models and empirical data suggest that humans are responsible for a great deal of the mercury actively cycling in the environment at present. Thus, one might predict that the concentration of mercury in fish should have increased dramatically since the Industrial Revolution. Evidence in support of this hypothesis has been hard to find, however, and some studies have suggested that analyses of fish show no change in mercury concentration. By compiling and re-analyzing published reports on yellowfin tuna (Thunnus albacares) caught near Hawaii (USA) over the past half century, the authors found that the concentration of mercury in these fish currently is increasing at a rate of at least 3.8% per year. This rate of increase is consistent with a model of anthropogenic forcing on the mercury cycle in the North Pacific Ocean and suggests that fish mercury concentrations are keeping pace with current loading increases to the ocean. Future increases in mercury in yellowfin tuna and other fishes can be avoided by reductions in atmospheric mercury emissions from point sources.

Atmospheric mercury emissions from China's primary nonferrous metal (Zn, Pb and Cu) smelting during 1949–2010

Primary nonferrous metal smelting is one of the most significant anthropogenic mercury emission sources. A spatially resolved mercury emission inventory over a long time span is essential for assessment of mercury source attribution and mercury transport modeling. In this study, based on updated technology-based emission factors, the atmospheric mercury emissions originating from primary zinc, lead and copper smelting in China were calculated. The inventory indicated that the total mercury emission from nonferrous metal smelting in China was 14.65 Mg in 2010, lower than the estimations in previous studies. The contributions of point and non-point sources were 23.3% and 76.7%, respectively. In 2010, the mercury emission from primary zinc, lead and copper smelting was 7.49, 6.05 and 1.10 Mg, respectively, and the Hg2+, Hg0 and HgP emissions were 8.10, 6.16 and 0.75 Mg, respectively. Spatially, the province with the largest emission was Sichuan, followed by Henan, Gansu, Shaanxi, Hunan and Yunnan provinces. The historical emissions were estimated based on dynamic emission factors that take the temporal technology changes into consideration. During 1949–2010, the cumulative mercury emission from China's nonferrous metal smelting was 323.0 Mg, of which the emission from lead smelting accounted for 44.6%, followed by zinc smelting (32.8%) and copper smelting (22.6%). From 1949 to 2010, the contribution of mercury emission from zinc smelting increased from 1.4% to 53.7%, while that from lead smelting showed a decreasing trend. For copper smelting, its contribution reached the maximum (40.1%) in 1987.

Mercury enrichment and its effects on atmospheric emissions in cement plants of China

The cement industry is one of the most significant anthropogenic sources of atmospheric mercury emissions worldwide. In this study of three typical Chinese cement plants, mercury in kiln flue gas was sampled using the Ontario Hydro Method (OHM), and solid samples were analyzed. Particulate matter recycling, preheating of raw materials, and the use of coal and flue gas desulfurization derived gypsum contributed to emissions of Hg in the air and to accumulation in cement. Over 90% of the mercury input was emitted into the atmosphere. Mercury emission factors were 0.044–0.072 g/t clinker for the test plants. The major species emitted into the atmosphere from cement plants is oxidized mercury, accounting for 61%–91% of the total mercury in flue gas. The results of this study help improve the accuracy of the mercury emission inventory in China and provide useful information for developing mercury controls.

A review of atmospheric mercury emissions, pollution and control in China

Mercury, as a global pollutant, has significant impacts on the environment and human health. The current state of atmospheric mercury emissions, pollution and control in China is comprehensively reviewed in this paper. With about 500–800 t of anthropogenic mercury emissions, China contributes 25%–40% to the global mercury emissions. The dominant mercury emission sources in China are coal combustion, non-ferrous metal smelting, cement production and iron and steel production. The mercury emissions from natural sources in China are equivalent to the anthropogenic mercury emissions. The atmospheric mercury concentration in China is about 2–10 times the background level of North Hemisphere. The mercury deposition fluxes in remote areas in China are usually in the range of 10–50 μg·m−2·yr−1. To reduce mercury emissions, legislations have been enacted for power plants, non-ferrous metal smelters and waste incinerators. Currently mercury contented in the flue gas is mainly removed through existing air pollution control devices for sulfur dioxide, nitrogen oxides, and particles. Dedicated mercury control technologies are required in the future to further mitigate the mercury emissions in China.

Spatial distribution and accumulation of Hg in soil surrounding a Zn/Pb smelter

Nonferrous metal smelting is an important atmospheric mercury (Hg) emission source that has significant local and global impacts. To quantify the impact of Hg emission from non-ferrous metal smelter on the surrounding soil, an integrated model parameterizing the processes of smelter emission, air dispersion, atmospheric deposition and Hg accumulation in soil was developed. The concentrations of gaseous elemental Hg (GEM) around the smelter and the spatial distribution of Hg in the surrounding soil were measured and compared with the model results. Atmospheric deposition of Hg emitted from the smelter was identified as the main source of Hg accumulation in the surrounding soil. From 1960 to 2011, the smelter emitted approximately 105t of Hg into the atmosphere, of which 15t deposited locally and resulted in an increase of Hg concentration in soil from 0.12 to 1.77mgkg−1. A detailed examination of wind rose and model data suggested that the area within 1.0–1.5km northwest and southeast of the smelter was most severely impacted. It was estimated that the smelter operation from 1969 to 1990, when large scale emission controls were not implemented, resulted in 6450μgm−2yr−1 of Hg net deposition and a model simulated increase of 0.40mgkg−1 of Hg accumulation in the soil. During the period from 1991 to 2011, atmospheric Hg emission from the smelter alone increased the average concentration in soil from 0.41mgkg−1 to 0.45mgkg−1. In the past 50years, over 86% of Hg emitted from this smelter went into the global pool, indicating the importance of controlling Hg emissions from non-ferrous metal smelters.

Virtual Atmospheric Mercury Emission Network in China

Top-down analysis of virtual atmospheric mercury emission networks can direct efficient demand-side policy making on mercury reductions. Taking China-the world's top atmospheric mercury emitter-as a case, we identify key contributors to China's atmospheric mercury emissions from both the producer and the consumer perspectives. China totally discharged 794.9 tonnes of atmospheric mercury emissions in 2007. China's production-side control policies should mainly focus on key direct mercury emitters such as Liaoning, Hebei, Shandong, Shanxi, Henan, Hunan, Guizhou, Yunnan, and Inner Mongolia provinces and sectors producing metals, nonmetallic mineral products, and electricity and heat power, while demand-side policies should mainly focus on key underlying drivers of mercury emissions such as Shandong, Jiangsu, Zhejiang, and Guangdong provinces and sectors of construction activities and equipment manufacturing. China's interregional embodied atmospheric mercury flows are generally moving from the inland to the east coast. Beijing-Tianjin (with 4.8 tonnes of net mercury inflows) and South Coast (with 3.3 tonnes of net mercury inflows) are two largest net-inflow regions, while North (with 5.3 tonnes of net mercury outflows) is the largest net-outflow region. We also identify primary supply chains contributing to China's virtual atmospheric mercury emission network, which can be used to trace the transfers of production-side and demand-side policy effects.

Benefits of European Climate Policies for Mercury Air Pollution

This paper presents the methodology and results of impact assessment of renewable energy policies on atmospheric emissions of mercury in Europe. The modeling exercise described here involves an interaction of several models. First, a set of energy scenarios has been developed with the REMix (Renewable Energy Mix) model that simulates different levels of penetration of renewable energies in the European power sector. The energy scenarios were input to the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) model, which prepared projections of mercury releases to the atmosphere through 2050, based on the current air pollution control policies in each country. Data on mercury emissions from individual sectors were subsequently disaggregated to a fine spatial resolution using various proxy parameters. Finally, the dispersion of mercury in the atmosphere was computed by the chemistry transport model, implemented to the air quality system, Polyphemus. The simulations provided information on changes in concentrations and depositions of various forms of mercury over Europe. Scenarios that simulate a substantial expansion of renewable energies within the power sector indicate extensive co-benefits for mercury abatement, due to the restructuring of the energy system and changes in the fuel mix. The potential for mercury reductions in Europe depends on the rate of fuel switches and renewable technology deployment, but is also influenced by the stringency and timing of the air quality measures. The overall scope for co-benefits is therefore higher in regions relying on coal combustion as a major energy source.

High‐resolution inventory of mercury emissions from biomass burning in China for 2000–2010 and a projection for 2020

AbstractBiomass burning is an important contributor of atmospheric mercury emissions. An inventory of mercury emissions from biomass burning with a high resolution and long time span is necessary for mercury transport modeling and emission reduction. In this study, an inventory of mercury emissions from biomass burning in China, with high spatial resolution and decade period (2000–2010), is presented, and the emission in 2020 is projected. Results showed that during 2000–2010, the annual average mercury emission from crop residues burning as fuel in household, crop residues burning as waste in fields, fuelwood burning in households, fuelwood burning for production, forest fires, and grassland fires was 2.30, 0.97, 1.66, 0.49, 0.78, and 0.01 Mg, respectively. The total emission was 6.20 Mg yr−1, lower than the results of previous studies. The majority of mercury species is in the form of Hg0, accounting for 78.9%, followed by Hgp (15.5%) and Hg2+ (5.6%). During 2000–2010, mercury emission from biomass burning decreased from 6.08 Mg in 2000 to 5.12 Mg in 2010. For spatial distribution, the mercury emissions were high in the eastern and central regions of China. Results from scenario analysis showed that mercury emission in 2020 is projected to be 6.18 Mg under the growth condition following the trend in 2005–2010 and 3.00 Mg under the condition of the anticipated new development mode. The results of this inventory study could provide useful information for further assessment of global mercury source attribution and mercury transport modeling.

The Minamata Convention on Mercury: A First Step toward Protecting Future Generations

In July 1956, in a fishing village near the city of Minamata on Japan’s Shiranui Sea, a baby girl named Shinobu Sakamoto was born. Her parents soon realized something was wrong. At 3 months old, when healthy babies can hold up their heads, Sakamoto could not. She grew slowly and began crawling unusually late. At age 3 years, she drooled excessively and still couldn’t walk. Her parents sent her to live at a local hospital, where she spent four years in therapy to learn to walk, use her hands, and perform other basic functions. Early on, several physicians agreed on a diagnosis of cerebral palsy.

Removal of mercury from flue gas using sewage sludge-based adsorbents

Mercury from coal-fired utility boilers, as the largest atmospheric mercury emission source, imposes serious environmental risks and health concerns. In order to explore the possibility of reducing costs of activated carbon injection, we investigated the most promising mercury control technology, Hg0 removal using ZnCl2-impregnated adsorbents derived from sewage sludge. The results demonstrated that sludge-based adsorbents (SBAs) had fairly high mercury adsorption capacity over a wide range of temperatures (80–170 °C). Oxidizing atmosphere could improve the adsorption of Hg0 and weaken the inhibition of SO2 on mercury adsorption to some extent. NO exhibited no obvious impact on mercury removal performance. In addition, to clarify whether oxygen- or chlorine-containing functional groups attributed to good mercury adsorption capacity of SBAs, the oxygen-containing functional groups were removed using Boehm’s method, and a temperature-programmed decomposition desorption experiment was conducted. The results suggest that chlorine-containing functional groups played a significant role in the removal process of mercury from flue gas using SBAs.

Study on the reduction of atmospheric mercury emissions from mine waste enriched soils through native grass cover in the Mt. Amiata region of Italy

Atmospheric mercury emissions from mine-waste enriched soils were measured in order to compare the mercury fluxes of bare soils with those from other soils covered by native grasses. Our research was conducted near Mt. Amiata in central Italy, an area that was one of the largest and most productive mining centers in Europe up into the 1980s. To determine in situ mercury emissions, we used a Plexiglas flux chamber connected to a portable mercury analyzer (Lumex RA-915+). This allowed us to detect, in real time, the mercury vapor in the air, and to correlate this with the meteorological parameters that we examined (solar radiation, soil temperature, and humidity). The highest mercury flux values (8000ngm−2h−1) were observed on bare soils during the hours of maximum insulation, while lower values (250ngm−2h−1) were observed on soils covered by native grasses. Our results indicate that two main environmental variables affect mercury emission: solar radiation intensity and soil temperature. The presence of native vegetation, which can shield soil surfaces from incident light, reduced mercury emissions, a result that we attribute to a drop in the efficiency of mercury photoreduction processes rather than to decreases in soil temperature. This finding is consistent with decreases in mercury flux values down to 3500ngm−2h−1, which occurred under cloudy conditions despite high soil temperatures. Moreover, when the soil temperature was 28°C and the vegetation was removed from the experimental site, mercury emissions increased almost four-fold. This increase occurred almost immediately after the grasses were cut, and was approximately eight-fold after 20h. Thus, this study demonstrates that enhancing wild vegetation cover could be an inexpensive and effective approach in fostering a natural, self-renewing reduction of mercury emissions from mercury-contaminated soils.

Analysis on Mercury Emission and Control Technology of Typical Industries in China

The mercury emission characteristics of coal-fired power plant boilers, industrial boilers, cement kilns, and sintering of iron and steel industry were studied in this paper. The reducing effect of mercury emissions by pollution control technology was analyzed. The EPA standard method was used to measure the mercury concentration of the pollution sources. For coal-fired boilers, the mercury removal efficiency of the existing electrostatic precipitator and wet FGD is up to 60%-70%, and the mercury concentration in the flue gas is below the standard 30μg/Nm3. The main mercury emissions of cement industries are at the kiln outlet, the mercury concentration of which is 2.5 to 5.4 times that of the kiln inlet. For the iron and steel industry, the mercury concentration of the exhausting gas after dust removal and desulfurization can not meet the emission limits and need to be further controlled. The research did in the paper made a scientific basis for the improvement of atmospheric mercury emission inventory and the mercury control.

313 廃棄物系粒子材料による排ガス中水銀吸収(大気環境保全・改善技術(1))

Atmospheric mercury emissions from coal combustion and waste incineration processes have been drawing attention as global pollutant. It has been reported that wet desulfurization process and/or absorbing bed of activated carbon, which are generally installed in domestic coal fired power plants, can control mercury emissions. However, considering the growing diversity of fuels including waste products and the overseas market development, a low-cost dry process for mercury removal from stack gas needs to be developed in near future. Objective in this study is to utilize particle materials derived from waste products to capture gaseous mercury. Mercury absorption experiments have bee n conducted using some mineral particles. As a result, calcined paper sludge showed the high performance for mercury absorption.

The UNEP Global Mercury Assessment: Sources, Emissions and Transport

Global Mercury Assessments (GMAs) have been produced as part of the UNEP Mercury Programme upon the request of UNEP Governing Council since 2001. The first GMA concluded that there is sufficient evidence of significant global adverse impacts from mercury and its compounds to warrant further international action to reduce the risks to human health and the environment from the release of mercury and its compounds to the environment. The follow-up “Global Atmospheric Mercury Assessment: Sources, Emissions and Transport” was delivered to the UNEP Governing Council in 2009. These reports formed the basis for the UNEP Governing Council policy decisions that have resulted in the ongoing (INC) process to establish a global legally binding instrument on mercury by 2013. UNEP is currently updating the 2008 “Global Atmospheric Mercury Assessment: Sources, Emissions and Transport,” for presentation to the UNEP Governing Council in early 2013. The updated report will present a new inventory of anthropogenic atmospheric mercury emissions for all countries, based on best available data from 2008-2010, including an analysis by sector and region. This part of the report is being developed by a joint AMAP/UNEP expert group. The report will also present updated information on atmospheric transport and deposition and – as a new addition – information on aquatic releases of mercury and on mercury fate and transport in aquatic environments. These parts of the report will be delivered by the UNEP Partnership Area on Mercury Fate and Transport. An outline of the methodology used to develop the report, and preliminary scientific results will be presented.

Large Industrial Point Sources in Italy: a focus on mercury concentrations resulting from three seasonal ship-borne measurements

In Italy there are 25 Large Industrial Point Sources whose mercury emissions in air exceed the established threshold of 10 kg year -1 . Many of these mercury point sources, mostly distributed along the Italian coastal area, are located at sites qualified as National Interest Rehabilitation Sites because of documented contamination in qualitative and/or quantitative terms and of potential health impact. Atmospheric mercury emissions related to Italian Large Industrial Point Sources, with a value of 1.04 Mg·yr -1 for 2007, have a not negligible contribution, accounting, on their own, for more than 10% of the total mercury emissions resulting from all activity sectors at a national level. Among others, thermal power stations, pig iron and steel as well as basic inorganic chemical production, result to be the main contributing industrial activities. In order to assess how mercury species concentrations and distribution in the Marine Boundary Layer (MBL) change with vicinity to large industrial sites, measurements of atmospheric mercury were performed during three oceanographic campaigns aboard the Research Vessel (R.V.) Urania of the Italian CNR. Collection of GEM, GOM and PBM was conducted across the Adriatic sea, during autumn 2004 (27 th of October to 12 th of November) and summer 2005 (17 th to 29 th of June), and across the Tyrrhenian sea during autumn 2007 (12 th of September to 1 st October). Analysis were carried out with reference to the period in which the R.V. Urania has stopped close to the main Italian industrial contaminated sites. Explorative statistical parameters of atmospheric mercury species were computed over each single stop-period and then compared with the overall cruise campaign measurements. Results are herein presented and discussed.

Ancillary Benefits of Climate Policies for the Mitigation of Atmospheric Mercury Emissions

This study provides an analysis of the impact of global climate policies on mercury emissions using the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model in the time horizon up to 2050. The time evolution of mercury emissions is based on projections of energy consumption provided by the Prospective Outlook for the Long term Energy System (POLES) model for a scenario without any global greenhouse gas mitigation efforts, and for a 2°C climate policy scenario, which assumes internationally coordinated action to mitigate climate change. Outcomes of the analysis are reported globally and for key world regions: EU-27, China, India and the US. The assessment takes into account current air pollution control legislation in each country. Scenario calculations for mercury emissions indicate significant scope for co-benefits made possible through climate policies. Atmospheric releases of mercury from anthropogenic sources under the global climate mitigation regime are reduced in 2050 by 45% when compared to the case without climate measures. Around one third of co-benefits for mercury emissions estimated world-wide in this study by 2050 are allocated to China. An annual Hg-abatement of about 800 tons is estimated for the coal combustion in power sector if the current air pollution legislation and climate policies are adopted in parallel.

Update of mercury emissions from China's primary zinc, lead and copper smelters, 2000–2010

Abstract. China is the largest anthropogenic mercury emitter in the world, where primary nonferrous metal smelting is regarded as one of the most significant emission sources. In this study, atmospheric mercury emissions from primary zinc, lead and copper smelters in China between 2000–2010 were estimated using a technology-based methodology with comprehensive consideration of mercury concentration in concentrates, smelting processes, mercury removal efficiencies of air pollution control devices (APCDs) and the application percentage of a certain type of APCD combinations. Our study indicated that atmospheric mercury emissions from nonferrous metal smelters in 2000, 2003, 2005, 2007 and 2010 were 67.6, 100.1, 86.7, 80.6 and 72.5 t, respectively. In 2010, the amounts of mercury emitted into atmosphere were 39.4 ± 31.5, 30.6 ± 29.1, and 2.5 ± 1.1 t from primary zinc, lead and copper smelters, respectively. The largest amount of mercury was emitted from the Gansu province, followed by Henan, Yunnan, Hunan, Inner Mongolia and Shaanxi provinces. Hg2+, Hg0 and Hgp emissions from zinc smelters were 25.6, 11.8 and 1.97 t, respectively. The emissions percentages of Hg2+ and Hg0 were almost the same from lead and copper smelters. The average mercury removal efficiency was 90.5 ± 52.5%, 71.2 ± 63.7% and 91.8 ± 40.7% in zinc, lead, and copper smelters, respectively.

Monte-Carlo human health risk assessment of mercury emissions from a MSW gasification plant

The potential impact of the atmospheric emission of mercury from a new waste gasification plant is assessed by means of a probabilistic approach based on probability density functions for the description of the input data (namely, emission rate of mercury gaseous and particulate species) and the model parameters involved in the individual risk exposure assessment through the pathways of inhalation, soil ingestion, dermal contact, and diet. The use of probability functions allowed the uncertainty in the input data and model parameters to be accounted for; the uncertainty was propagated throughout the evaluation by Monte Carlo technique, resulting in the probability distributions for the ambient air and soil concentrations nearby the plant and for the subsequent individual risk, estimated in terms of hazard index for both an adult and a child receptor. The estimated median concentration levels in air and soil are respectively in the 1.6×10−3–2.2×10−2ngm−3 range and in the 3.5×10−4–1.7×10−2mgkg−1 range, that is at least two orders of magnitude lower than the current background concentration in the ambient air and one order of magnitude lower than the concentration locally measured in the soil. The diet pathway is responsible for the most part (>80%) of the daily mercury intake, which, however, is at least four (median estimated values) and three orders (estimates for a reasonable maximum exposure) lower than the reference dose in the most part of the modeling domain. According to the locally measured background mercury levels in air and soil the additional contribution of the plant emissions to the environmental mercury levels appears of small significance, with an almost negligible impact on the hazard index for the population living in the neighborhood of the plant.