Mercury emissions to the atmosphere from anthropogenic sources in Europe in 2000 and their scenarios until 2020

The paper reviews the current state of knowledge regarding European emissions of mercury and presents estimates of European emissions of mercury to the atmosphere from anthropogenic sources for the year 2000. This information was then used as a basis for Hg emission scenario development until the year 2020. Combustion of coal in power plants and residential heat furnaces generates about half of the European emissions being 239 tonnes. The coal combustion is followed by the production of caustic soda with the use of the Hg cell process (17%). Major points of mercury emission generation in the mercury cell process include: by-product hydrogen stream, end box ventilation air, and cell room ventilation air. This technology is now being changed to other caustic soda production technologies and further reduction of Hg emissions is expected in this connection. The third category on the list of the largest Hg emitters in Europe is cement production (about 13%). The largest emissions were estimated for Russia (the European part of the country), contributing with about 27% to the European emissions, followed by Poland, Germany, Spain, Ukraine, France, Italy and the United Kingdom. Most of these countries use coal as a major source of energy in order to meet the electricity and heat demands. In general, countries in the Central and Eastern Europe generated the main part of the European emissions in 2000. Emission reductions between 20% and 80% of the 2000 emission amounts can be obtained by the year 2020, as estimated by various scenarios.     

Mercury emissions from a coal-fired power plant in Japan

The emissions study for mercury was conducted at a 700 MW coal-fired plant for the combustion of three types of coal with mercury concentrations of 0.0063, 0.0367 and 0.065 mg/kg. The power plant is equipped with a cold-side electrostatic precipitator and wet type flue gas desulfurization system. During full load operation of the boilers, samples of the input and output streams such as coal, coal ash, ESP ash and post-ESP particulates and flue gas were collected. The Hg concentrations in solid were measured by cold-vapor atomic absorption spectrometry (AAS) after appropriate preparation and acid digestion. Gaseous Hg was collected using a mixed solution of potassium permanganate and sulfuric acid and the Hg concentrations in the samples were measured using cold-vapor AAS. The results were used to examine: (1) overall mass balances; (2) relative distribution in the power plant; (3) equilibrium of Hg species using MALT-2 calculation program; and (4) Hg concentrations in stack emissions. The mass balances estimated in this study were 100, 138 and 89%, respectively, for the coals. Total Hg concentrations in stack gas were 1.113, 0.422 and 0.712 microg(m3N), respectively, for the coals. More than 99.5% of the Hg in the stack emissions were in gaseous form and the proportion in particulate form was extremely low. The relative distribution of Hg in ESP, FGD and Stack ranged from 8.3 to 55.2%, 13.3 to 69.2% and 12.2% to 44.4%, respectively. The results indicated that factors other than the Hg concentration of coals and efficiency of pollution control devices might affect Hg emissions from coal-fired plant. The calculated equilibrium of the distribution of Hg species using the MALT2 program suggest that it is necessary to consider condensation mechanism to interpret the affect of Hg species on the variations of the removal efficiencies of Hg in the ESP.     

Air emissions from municipal waste combustion and their environmental effects

This paper addresses risk-assessment estimates associated with air emissions from MWC facilities via the inhalation pathway. Calculations performed address selected chemical constituents with the potential highest human health effects. The calculated carcinogenic risks are small and are well below the EPA acceptable risk of 10(-4). Similarly, the calculated noncarcinogenic risks are well below the acceptable reference dose values. Calculations presented in this paper for selected constituents could be expanded to additional chemical constituents.     

Sensory evaluation of emissions from selected building products exposed to ozone

The interaction of ozone with eight different building products was studied in test chambers. The products were plasterboard, two types of paints on plasterboard, two types of carpet, linoleum, pinewood, and melamine-covered particleboard. Four months of conditioning prior to the experiment had left the products with a low emission. The products' ability to remove ozone from the air covered a wide range. For three of the products (plasterboard with paint, carpet, and pinewood), it was shown that the removal was primarily due to interactions in the products' surfaces and only to a minor extent due to gas-phase reactions. Sensory evaluations were carried out for five of the products, with different ozone-removal potentials. A sensory panel assessed the emissions from sets of two specimens of each product; one specimen was exposed to a high, but realistic, ozone concentration (10 or 80 ppb) and one specimen was exposed to no ozone (background level < 3 ppb). The panel assessed odor intensity and was asked to choose which odor of the two specimens they preferred. The perceivable changes in emissions due to exposure of the products to ozone depended on the type of product. The greatest effect was seen for carpet. Carpet was the only product that showed significantly higher odor intensity when exposed to ozone. Besides, the effect of ozone on preference was strongest for carpet and resulted in a clear negative sensory evaluation. A similar but less pronounced effect was seen for pinewood and plasterboard with paint. No clear preference was seen for melamine and linoleum.     

Monitoring and analysis of combustion aerosol emissions from fast moving diesel trains

In this paper we report the results of the detailed monitoring and analysis of combustion emissions from fast moving diesel trains. A new highly efficient monitoring methodology is proposed based on the measurements of the total number concentration (TNC) of combustion aerosols at a fixed point (on a bridge overpassing the railway) inside the violently mixing zone created by a fast moving train. Applicability conditions for the proposed methodology are presented, discussed and linked to the formation of the stable and uniform mixing zone. In particular, it is demonstrated that if such a mixing zone is formed, the monitoring results are highly consistent, repeatable (with typically negligible statistical errors and dispersion), stable with respect to the external atmospheric turbulence and result in an unusual pattern of the aerosol evolution with two or three distinct TNC maximums. It is also shown that the stability and uniformity of the created mixing zone (as well as the repeatability of the monitoring results) increase with increasing length of the train (with an estimated critical train length of ~ 10 carriages, at the speed of ~ 150 km/h). The analysis of the obtained evolutionary dependencies of aerosol TNC suggests that the major possible mechanisms responsible for the formation of the distinct concentration maximums are condensation (the second maximum) and thermal fragmentation of solid nanoparticle aggregates (third maximum). The obtained results and the new methodology will be important for monitoring and analysis of combustion emissions from fast moving trains, and for the determination of the impact of rail networks on the atmospheric environment and human exposure to combustion emissions.     

Mercury emissions from coal-fired power stations: The current state of the art in the Netherlands

About 30% of the electricity produced in the Netherlands is generated by coal, all of which is imported. At the same time, the co-combustion of biomass is becoming increasingly important. For the last 25 years, the fate of the elements/trace elements in general and of mercury in particular has been studied in great detail. It appears that on average 50% of the mercury is removed in the ESP (particulate control) and 50% of the remainder is removed in the flue gas desulphurization (FGD), resulting in a total mercury removal of 75%. If a high dust selective catalytic reduction (SCR for NO(x) reduction) is present, the total removal can be up to 90%. The results indicate that on average the removal of mercury during the co-combustion of biomass is similar to that found for full coal-firing. The conclusion is that a modern coal-fired power station with the above-mentioned flue gas cleaning equipment also removes mercury up to 90%. These cleaning devices are being installed to reduce the emission of particulates, sulphur dioxide and nitrogen oxides. This means that mercury abatement can be increased while meeting the EU regulation for SO(2) and NO(x). The application of Best Available Technique (BAT) for coal-fired installations by 1-1-2008 will lead to a further increase in the construction and operation of FGD and DeNO(x) installations.     

Identifying key sources of uncertainty in the modelling of greenhouse gas emissions from wastewater treatment

This study investigates sources of uncertainty in the modelling of greenhouse gas emissions from wastewater treatment, through the use of local and global sensitivity analysis tools, and contributes to an in-depth understanding of wastewater treatment modelling by revealing critical parameters and parameter interactions. One-factor-at-a-time sensitivity analysis is used to screen model parameters and identify those with significant individual effects on three performance indicators: total greenhouse gas emissions, effluent quality and operational cost. Sobol's method enables identification of parameters with significant higher order effects and of particular parameter pairs to which model outputs are sensitive. Use of a variance-based global sensitivity analysis tool to investigate parameter interactions enables identification of important parameters not revealed in one-factor-at-a-time sensitivity analysis. These interaction effects have not been considered in previous studies and thus provide a better understanding wastewater treatment plant model characterisation. It was found that uncertainty in modelled nitrous oxide emissions is the primary contributor to uncertainty in total greenhouse gas emissions, due largely to the interaction effects of three nitrogen conversion modelling parameters. The higher order effects of these parameters are also shown to be a key source of uncertainty in effluent quality.     

Urinary mercury in people living near point sources of mercury emissions

As part of the European Mercury Emissions from Chlor Alkali Plants (EMECAP) project, we tested the hypothesis that contamination of ambient air with mercury around chlor alkali plants using mercury cells would increase the internal dose of mercury in people living close to the plants. Mercury in urine (U-Hg) was determined in 225 individuals living near a Swedish or an Italian chlor alkali plant, and in 256 age- and sex-matched individuals from two reference areas. Other factors possibly affecting mercury exposure were examined. Emissions and concentrations of total gaseous mercury (TGM) around the plants were measured and modeled. No increase in U-Hg could be demonstrated in the populations living close to the plants. This was the case also when the comparison was restricted to subjects with no dental amalgam and low fish consumption. The emissions of mercury to air doubled the background level, but contributed only about 2 ng/m(3) to long-term averages in the residential areas. The median U-Hg levels in subjects with dental amalgam were 1.2 microg/g creatinine (micro/gC) in Italy and 0.6 microg/gC in Sweden. In individuals without dental amalgam, the medians were 0.9 microg/gC and 0.2 microg/gC, respectively. The number of amalgam fillings, as well as chewing, fish consumption, and female sex were associated with higher U-Hg. The difference between the countries is probably due to higher fish consumption in Italy, demethylated methyl mercury (MeHg) being partly excreted in urine. Post hoc power calculations showed that if the background mercury exposure is low it may be possible to demonstrate an increase in U-Hg of as little as about 10 ng/m(3) as a contribution to ambient mercury from a point source.     

Respiratory responses to diverse indoor combustion air pollution sources

Diverse indoor combustion sources contribute to the indoor air environment. To evaluate the effect of these sources on human respiratory health, we examined associations between respiratory conditions and household factors in the 2360 children's fathers (mean = 38.4 years old) and associations between lung function and household factors in 463 primary school children (mean = 8.3 years old) from Wuhan, China. Factor analysis developed new uncorrelated 'factor' variables. Unconditional logistic regression models or linear regression models, controlling for important covariates, estimated the respiratory health effects. Coal smoke derived from home heating ('heating coal smoke') was associated with high adult reporting of persistent cough, persistent phlegm, and wheeze. Cooking coal smoke was associated with physician-diagnosed adult asthma and decreased forced vital capacity (FVC), and forced expiratory volume at 1 s (FEV(1)) in children. The presence of any home cigarette smoker was associated with more reports of persistent cough, persistent phlegm, cough with phlegm, and bronchitis. Our study suggests that in Wuhan, there may be independent respiratory health effects of different indoor combustion sources and their exposure factors for these study populations. PRACTICAL IMPLICATIONS: We conclude that multiple indoor air pollution sources could have adverse respiratory health effects on both children and middle-aged men in the city of Wuhan, China. These results may have implications for the Wuhan local government, the Chinese government, or other related organizations in efforts on protecting public health through regulation of indoor air pollution from indoor combustion sources.     

Evaluation of a method for measuring hydrochloric acid in combustion source emissions

A sampling and analytical method for measuring gaseous hydrochloric acid emissions from combustion sources has been evaluated. A laboratory evaluation of the most practical titrimetric procedure for chloride ion was performed. Upon selection of the procedure, the problem of interferences anticipated during source measurements was addressed. Remedios were found effective for eliminating the interferences. Following the laboratory studies, several combusion sources including both coal-fired boilers and municipal incinerators were sampled. The methodology was found to measure hydrochloric acid within the concentration range predicted, where applicable, from theoretical calculations.     

Characterization of aerosols emissions from the combustion of dead shrub twigs and leaves using a cone calorimeter

This work is a contribution to the understanding of wildfire smoke emissions. It focuses on the characterization of aerosols emitted by the combustion of dead shrub leaves and twigs with different thickness (range of 0.75–20 mm). The experiments were carried out at bench scale with a cone calorimeter for the burning of Cistus monspeliensis leaves and twigs. Auto-ignition of the samples was obtained by heating their surface with a radiant heat flux of 50 kW/m². The smoke and aerosols emitted before ignition during pre-heating were analysed separately from the smoke and aerosols emitted during the flaming phase. Heat release rate (HRR) was also measured and we observed two different behaviours depending on the diameter of the twigs. Fuel samples with diameter smaller than 4 mm exhibit a single peak HRR whereas two peaks were observed for the twigs with larger diameters. The smoke production rate (SPR) was also measured and it showed that smoke was mainly emitted during the pre-heating phase. We also obtained a strong correlation between HRR and SPR during the flaming phase but no smoke was emitted during the glowing phase. Emission factors of aerosols were calculated depending on these combustion phases (pre-ignition and flaming) and for the range of thickness of the samples. The observations of the aerosols were performed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The chemical composition of organic carbon (OC) aerosols, emitted during the pre-ignition phase, were analysed using gas chromatography (GC) coupled with mass spectrometry (MS). Some carcinogenic compounds were identified. The sizes of OC and black carbon (BC) aerosols emitted were measured with an optical device. Most of the BC were PM_0.3, which corresponds to the alveolar fraction of particles.     

Inhibition of progesterone receptor activity in recombinant yeast by soot from fossil fuel combustion emissions and air particulate materials

Numerous environmental pollutants have been detected for estrogenic activity by interacting with the estrogen receptor, but little information is available about their interactions with the progesterone receptor. In this study, emission samples generated by fossil fuel combustion (FFC) and air particulate material (APM) collected from an urban location near a traffic line in a big city of China were evaluated to interact with the human progesterone receptor (hPR) signaling pathway by examining their ability to interact with the activity of hPR expressed in yeast. The results showed that the soot of a petroleum-fired vehicle possessed the most potent anti-progesteronic activity, that of coal-fired stove and diesel fired agrimotor emissions took the second place, and soot samples of coal-fired heating work and electric power station had lesser progesterone inhibition activity. The anti-progesteronic activity of APM was between that of soot from petroleum-fired vehicle and soot from coal-fired establishments and diesel fired agrimotor. Since there was no other large pollution source near the APM sampling sites, the endocrine disrupters were most likely from vehicle emissions, tire attrition and house heating sources. The correlation analysis showed that a strong relationship existed between estrogenic activity and anti-progesteronic activity in emissions of fossil fuel combustion. The discoveries that some environmental pollutants with estrogenic activity can also inhibit hPR activity indicate that further studies are required to investigate potential mechanisms for the reported estrogenic activities of these pollutants.     

A comparison of in situ and extractive measurement techniques for monitoring SO2 emissions from a stationary source

Recently, an investigation has been completed which compared both extractive and in situ electro-optical instrumentation for the measurement of SO₂ emissions from a pulverized-coal power generating boiler. An assessment was made of individual system performance under field conditions. To accomplish this, particular areas of interest in this study included: (1) an investigation of the effects of variations in fuel composition, boiler operating conditions and fly ash emissions on the various measurement systems; (2) a correlation of instrument response with standard EPA compliance test methods; and (3) a determination of several instrument operating criteria such as zero drift, span drift, and maintenance.     

物料衡算法测算煤炭燃烧污染物排放量

通过分析煤炭燃烧可能产生各项污染物量的受影响因素,总结了煤炭燃烧产生各项污染物的经验计算公式,并提出了不同燃烧方式、不同煤质及不同脱硫除尘设施影响污染物排放量的各项经验系数,并以大同地区煤炭煤质资料为基础,计算出了1t煤炭燃烧后各项污染物的排放量,为污染物治理提供依据.     

Particulate emission factors for mobile fossil fuel and biomass combustion sources

PM emission factors (EFs) for gasoline- and diesel-fueled vehicles and biomass combustion were measured in several recent studies. In the Gas/Diesel Split Study (GD-Split), PM_2.5 EFs for heavy-duty diesel vehicles (HDDV) ranged from 0.2 to ~ 2 g/mile and increased with vehicle age. EFs for HDDV estimated with the U.S. EPA MOBILE 6.2 and California Air Resources Board (ARB) EMFAC2007 models correlated well with measured values. PM_2.5 EFs measured for gasoline vehicles were ~ two orders of magnitude lower than those for HDDV and did not correlate with model estimates. In the Kansas City Study, PM_2.5 EFs for gasoline-powered vehicles (e.g., passenger cars and light trucks) were generally < 0.03 g/mile and were higher in winter than summer. EMFAC2007 reported higher PM_2.5 EFs than MOBILE 6.2 during winter, but not during summer, and neither model captured the variability of the measured EFs. Total PM EFs for heavy-duty diesel military vehicles ranged from 0.18 ± 0.03 and 1.20 ± 0.12 g/kg fuel, corresponding to 0.3 and 2 g/mile, respectively. These values are comparable to those of on-road HDDV. EFs for biomass burning measured during the Fire Laboratory at Missoula Experiment (FLAME) were compared with EFs from the ARB Emission Estimation System (EES) model. The highest PM_2.5 EFs (76.8 ± 37.5 g/kg) were measured for wet (> 50% moisture content) Ponderosa Pine needles. EFs were generally < 20 g/kg when moisture content was < 20%. The EES model agreed with measured EFs for fuels with low moisture content but underestimated measured EFs for fuel with moisture content > 40%. Average EFs for dry chamise, rice straw, and dry grass were within a factor of three of values adopted by ARB in California's San Joaquin Valley (SJV). Discrepancies between measured and modeled emission factors suggest that there may be important uncertainties in current PM_2.5 emission inventories.     

Mercury removal from petrochemical wastes

The precipitation of mercury as mercury-starch-xanthate is studied. The process is studied in terms of optimum mercury-xanthate molar ratio, of influence of flocculation sedimentation times and of interferences (aluminum, iron, silica, chloride, organic substances and suspended solids).The studied reaction is advantageously applied to mercury removal from petrochemical wastes. The optimized process is applied both to a simulated and to a real wastewater, coming from a petrochemical industry (ANIC-Ravenna, Italy).     

Mercury concentrations in cattle from NW Spain

Mercury is a toxic metal that is released into the environment as a result of various industrial and agricultural processes. It can be accumulated by domestic animals and so contaminate human foodstuffs. To date, there is no information on mercury residues in livestock in Spain and the aim of the present study was to quantify the concentrations of mercury in cattle in two of the major regions in north-west Spain, Galicia (a largely rural region) and Asturias, which is characterised by heavy industry and mining. Total mercury concentrations were determined in tissue (liver, kidney and muscle) and blood from 284 calves (6-10 months old) and 56 cows (2-16 years old) from across the whole of the two regions. Mercury was usually detected in the kidney (62.4-87.5% of samples) but most (79.5-96%) liver, muscle and blood samples did not contain detectable residues. Renal mercury concentrations did not differ between male and female calves but were significantly greater in female calves than in cows. Unexpectedly, kidney mercury concentrations were significantly higher in calves from the predominantly rural region of Galicia (geometric mean: 12.2 microg/kg w.wt.) than in animals from the industrialised-mining region of Asturias (3.40 microg/kg w.wt.). Overall, mercury residues in cattle from NW Spain were similar to those reported in cattle from non-polluted areas in other countries and do not constitute a risk to animal or human health.     

Real-time analysis of soot emissions from bituminous coal pyrolysis and combustion with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer

This paper reports on-line analyses of the soot emissions from the Inner Mongolia bituminous coal combustion and pyrolysis processes with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The soot particles are generated by heating a small amount of screened coal powder in synthetic air and nitrogen atmosphere in a tubular oven. The vacuum ultraviolet photoionization time-of-flight (VUV-TOF) mass spectra of the soot particles emitted from combustion and pyrolysis at different oven temperatures and different stages are obtained. The VUV-TOF mass spectra are assigned with the references of the results of the off-line GC/MS analysis.     

Isothiazolone emissions from building products

Adding biocides to dispersion products is a well‐known practice to control microbial deterioration. Isothiazolones are among the most commonly used preservatives, in particular a mixture of 2‐methyl‐2H‐isothiazol‐3‐one (MIT) and 5‐chloro‐2‐methyl‐2H‐isothiazol‐3‐one (CIT). In recent years, for health reasons, due to its strong sensitizing effect, CIT has been replaced by 1,2‐benzisothiazol‐3‐one (BIT). Furthermore, numerous products are now available for interiors containing the fungicidal active substance 2‐octyl‐2H‐isothiazol‐3‐one (OIT). So far nearly nothing is known of the emission behavior of BIT and OIT. An analytical method was developed for these two isothiazolones and interior products containing BIT respectively OIT have been investigated in an emission chamber and in test rooms. The chamber tests revealed maximum concentrations of 6.7 μg OIT/m³, 1.9 μg BIT/m³, and 187 μg MIT/m³. Concentrations obtained in the test rooms were at levels up to 1.4 μg OIT/m³ and 29 μg MIT/m³. A noticeable finding was the very slight subsidence of OIT and BIT levels over several weeks. While MIT outgassed quickly, OIT in particular showed low concentrations, but prolonged evaporation.