Measurements of the magnetic properties and total contents of Cu, Cd, Pb and Fe in 30 automobile emission particulate samples indicated the presence of magnetic particles in them. The values of frequency dependent sus...Measurements of the magnetic properties and total contents of Cu, Cd, Pb and Fe in 30 automobile emission particulate samples indicated the presence of magnetic particles in them. The values of frequency dependent susceptibility (Xfd) showed the absence of superparamagnetic (SP) grains in the samples. The IRM20mT (isothermal remanent magnetization at 20 mT) being linearly proportional to SIRM (saturation isothermal remanent magnetization) (R^2=0.901), suggested that ferrimagnetic minerals were responsible for the magnetic properties of automobile emission particulates. The average contents of Cu, Cd, Pb and Fe in automobile emission particulates were 95.83, 22.14, 30.58 and 34727.31 mg/kg, respectively. Significant positive correlations exist between the magnetic parameters and the contents ofPb, Cu and Fe. The magnetic parameters of automobile emission particulates reflecting concentration of magnetic particles increased linearly with increase of Pb and Cu content, showed that the magnetic measurement could be used as a preliminary index for detection of Pb and Cu pollution.展开更多
Simulations from the Weather Research and Forecasting Model, inline coupled with chemistry, were used to examine the fate of particulate matter with diameter of 10 μm or less (PM10) in Glacier Bay, Alaska during the ...Simulations from the Weather Research and Forecasting Model, inline coupled with chemistry, were used to examine the fate of particulate matter with diameter of 10 μm or less (PM10) in Glacier Bay, Alaska during the 2008 tourist season. The simulations demonstrated that mesoscale and synoptic scale weather systems affect the residence time of PM10, the magnitude of concentrations, and its transport in and out of Glacier Bay. Strong inversions exceeding 2 K (100 m)-1 cause notable trapping of pollutants from cruise-ship emissions, increasing PM10 concentrations up to 43% compared to days with cruise-ship visits without the presence of an inversion. Inversions occurred locally in Glacier Bay on 42% of the 124-day tourist season with an average lifetime of 9 h. Pollutants occasionally originated from outside the National Park when southerly winds advected pollutants from ship traffic in Icy Strait. Occasionally, orographically forced lifting over the Fairweather Mountains transported pollutants from the Gulf of Alaska into Glacier Bay. While hourly (daily) PM10 concentrations reached ~44 μg·m-3 (22 μg·m-3) in some areas of Glacier Bay, overall seasonal average PM10 concentrations were below 2 μg·m-3. Despite up to two cruise-ship visits per day, Glacier Bay still has pristine air quality. Surface and upper air meteorological state variables were evaluated through an extensive network of surface and radiosonde observations, which demonstrated that the model was able to capture the meteorological conditions well.展开更多
Road transport exhaust emissions represent the main sources of atmospheric pollution in urban areas, due to the growing number of circulating vehicles and travelled distances. In order to reduce this pollution source,...Road transport exhaust emissions represent the main sources of atmospheric pollution in urban areas, due to the growing number of circulating vehicles and travelled distances. In order to reduce this pollution source, stricter emission standards are periodically set by governments through- out the world. Consequently, the concentrations of gaseous pollutants and particulate mass to be measured during type-approval tests of new vehicles are becoming progressively lower;moreover from 2011, diesel cars have to comply with particle number limit. In order to assess emission levels of different technology vehicles and investigate the use of a particulate number measurement technique at the exhaust of very low-emitting vehicles, an experimental activity was carried out on three in-use vehicles: a diesel car equipped with a particulate trap (DPF), a hybrid gasoline-elec- tric car and a bi-fuel passenger car fuelled with compressed natural gas (CNG). Cold and hot gaseous and particulate emission factors and fuel consumption were measured during the execution of real and regulatory driving cycles on a chassis dynamometer. Particulate was characterized in terms of mass only for the diesel car and of particle number for all vehicles. The emissions measured over the NEDC show that all three vehicles comply with their standard limits, except CO for CNG passenger car and NOx for diesel car. Cold start influences CO and HC emissions and fuel consumption for all the tested vehicles and in particular for the hybrid car. The real driving cycle is the most critical pattern for the emissions of almost all pollutants. During constant speed tests, the emissions of particles of hybrid car are an order of magnitude lower than those of the CNG car.展开更多
The nested-grid capability of the global chemical transport model GEOS-Chem, with a horizontal resolution of 1/4°× 5/16° (latitude x longitude), was used to identify the chemical species whose reducti...The nested-grid capability of the global chemical transport model GEOS-Chem, with a horizontal resolution of 1/4°× 5/16° (latitude x longitude), was used to identify the chemical species whose reductions made the largest contributions to decreases in PM2.s concentrations (fine particulate matter, diameter 〈 2.5μm, defined in this study as the sum of sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols) in Beijing during the 2014 Asia-Pacific Economic Cooperation (APEC) summit. A number of numerical experiments were carried out for the period 15 October-29 November 2014. The model reproduced the observed daily variations of concentrations of PM2.s and gas-phase species (carbon monoxide, nitrogen dioxide, and sulfur dioxide). Simulated PM2.s concentrations decreased by 55.9%-58.5% during the APEC period, compared to other periods in October and November 2014, which agreed closely with measurements. Sensitivity results showed that emissions control measures regarding nitrogen oxides and organic carbon over North China led to the largest reductions in PM2.s concentrations in Beijing during the APEC summit, which led to overall reductions in the PM2.5 concentration of Beijing by 5.7% and 4.6%, respectively. The control of ammonia emissions was found to be able to greatly reduce PM2.5 concentrations in the whole of North China during the APEC meeting.展开更多
Transport fuels emit particulates of varying chemical nature and size. These particulates are known to cause respiratory problems of medical concern. The need to simulate the breathing characteristics of particulates ...Transport fuels emit particulates of varying chemical nature and size. These particulates are known to cause respiratory problems of medical concern. The need to simulate the breathing characteristics of particulates generated from combustion events is very important in estimating the respiratory clearance of these particles. Consequently, this study examines the nature of particulate matter from the pyrolysis of a mixture Croton megalocarpus biodiesel and fossil diesel, and pure biodiesel. The study was explored at an optimum temperature of 600°C in an inert nitrogen environment at a contact time of 2 sec. Scanning electron microscope was used to examine the surface of the particulates. Multiple-Path Particulate Dosage (MPPD Ver. 3.04) model was used to determine the breathing phenomena of infants, teenagers and adults at different orientations. Co-pyrolytic Char particulates and pyrolytic croton thermal char were classified as ultrafine, PM0.03 and PM0.02 respectively. The MPPD model results indicated that ultrafine particles tend to be deposited in pulmonary regions more than head and trachea regions, due to high probability of diffusibiliy of ultrafine particles. It was noted that 8 years old exhibits a unique trend with high total deposition and poor respiratory clearance when compared to an adult of 21 years old.展开更多
The study investigated the effects of four major particulate matter (PM) components namely sulphur, pulsar ash, carbon residue and ammonium components on the physical damage of sugarcane. A cyclone ambient kit tetra d...The study investigated the effects of four major particulate matter (PM) components namely sulphur, pulsar ash, carbon residue and ammonium components on the physical damage of sugarcane. A cyclone ambient kit tetra detector was used to quantify the components of the particulate matter at 2, 4, 6 and 8 km both in the windward and leeward sides of the power plant. This was done during the oncrop and offcrop season over a period of sixteen weeks. Eight sampling points were selected in an area of 2500 m2. Plant leaves were visually assessed for physical damage and the percentage of damage was noted. The results of the study were analyzed using SPSS version 16 and General Linear model-multivariate analysis to determine variation between the different means of components. Results showed that all PM components were only detected in the leeward side throughout the oncrop season and in the first two weeks of the offcrop. Ash and carbon deposition decreased with increasing distance. Ammonium components and sulphur were deposited only at 6 and 8 km. The percentage damage of the sugar cane was observed in the leeward side during the oncrop season. The physical damage caused by carbon and ash was observed in the 2 and 4 km distances whereas that caused by ammonium components and sulphur was observed in the 6 and 8 km distances.展开更多
Emission factors (EFs) of particulate matter (PM) derived from mono and co-firing of Thai lignite and agricultural residues have been investigated. Two sampling methods for PM, total filtration (TF) and electric...Emission factors (EFs) of particulate matter (PM) derived from mono and co-firing of Thai lignite and agricultural residues have been investigated. Two sampling methods for PM, total filtration (TF) and electrical low-pressure impactor (ELPI), were used together. The study is focused on the influence of fuel mass fraction, and of secondary air to total air; SA:TA on EFs of PM. The results have shown that EFs of PM in mass-basis given by TF method are 8.9, 5.3 and 8.1 mg/kgfuel, while 3.3, 2.7 and 3.3 mg/kgfuel when using ELPI, for firing at constant SA:TA (30%) of lignite, rice husk and bagasse, respectively. For co-firing with 30%SA of coal/rice husk, higher EFs of PM is observed. They are 7.17 and 10.9 mg/kgfuel (TF) for 40 and 70% rice husk share, respectively, or 4.18 and 5.19 mg/kgfuel (ELPI). However, lower PM emission; 1-3.3 mg/kgruel (TF) or 0.72-2.83 mg/kgfuel (ELPI) are obtained during co-firing of coal/rice husk with lower degree of air staging (i.e. 0-10% SA:TA). For the influence of oxygenation state, increasing of SA: TA leads to a low formation of ultrafine particles (Dp 〈 0.1 μm). Apart from PM, major gases (CO, NO, SO2) will be documented in this paper.展开更多
Aiming at the problem of soot concentration measurement under ultra-low emission conditions,a forward small angle soot concentration measurement method is proposed.Taking a typical boiler emission of 0.1μm-3.0μm bim...Aiming at the problem of soot concentration measurement under ultra-low emission conditions,a forward small angle soot concentration measurement method is proposed.Taking a typical boiler emission of 0.1μm-3.0μm bimodal distribution soot as an object,the particle scatter simulation calculation under different parameters is carried out,and the influence of detection angle and particle size on the angular scatteringmeasurement of ultra-low emission soot is analyzed.The influence of detection angle and particle size on the angular scatteringmeasurement of ultra-lowemission soot is analyzed.Preferably,thewavelength of incident light is 650 nm,and the forward detection angle parameter is 15◦for the design of forward small angle soot concentration measurement system.An experimental system for measuring soot with standard concentration is built.Experiments of particle concentration measurement of 1.0μm and 3.0μm under ultra-low emission conditions are carried out.The results show that the average deviation of soot concentration measurement is less than 0.10 mg/m3 under the condition of ultra-low emission by using 15◦of forward detection,which provides an effective way for monitoring ultra-low emission soot concentration in coal-fired power plants.展开更多
From the perspective of development background,concepts and related policies of ultra-low emission,according to work practice,some issues and difficulties that need to be paid attention to in the environmental impact ...From the perspective of development background,concepts and related policies of ultra-low emission,according to work practice,some issues and difficulties that need to be paid attention to in the environmental impact assessment of ultra-low-emission thermal power projects were discussed from the aspects of evaluation criteria,evaluation grade and scope,pollution control technical lines,environmental benefit accounting,and total emission control,and corresponding recommendations were put forward.展开更多
Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen...Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit.The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines.The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm.About 93%of the particles are evaporated and absorbed when using a thermodenuder,and thus a large majority of the particles are volatile.Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.展开更多
Domestic burning emits large amounts of pollutants into the ambient air due to incomplete and inefficient combustion, with significant impacts on indoor air quality and human health. Northeast China is one of the majo...Domestic burning emits large amounts of pollutants into the ambient air due to incomplete and inefficient combustion, with significant impacts on indoor air quality and human health. Northeast China is one of the major contributors to domestic burning emissions in China;however, the high-resolution emissions inventories of domestic biomass and coal burning in Northeast China are lacked, which are needed to estimate the extent of its impact. In this study, we established a town-level emissions inventory of gaseous pollutants and particulate matter(PM) from domestic biomass and coal burning, based on per household consumption in each town in rural region of Northeast China. The results revealed that biomass burning was the major domestic burning source over the region in 2016. Domestic biomass burning is the major contributor to PM and volatile organic compounds(VOCs) emissions, while coal burning is the major contributor to SO2 emissions. High emissions intensities were concentrated around the cities of Harbin, Suihua, Changchun, Qiqihar, and Chifeng, each with emissions intensity for PM2.5 and VOCs of more than 2000 Mg per 27 km × 27 km grid cell. Additionally, there are three burning peaks(6-7 am, 12 pm and 4-7 pm) during both the heating(from October to April) and non-heating seasons(from May to September), due to cooking and heating. The burning peaks in the non-heating season were more notable than those in the heating season. These results suggest that the government should pay more attention to domestic biomass and coal burning in rural areas, in order to reduce pollutant emissions and control regional haze during the heating season.展开更多
<span><span>The transportation sector is certainly one of the main agent’s principals </span><span>and </span><span>has contributed to the increase in global air pollution. In Braz...<span><span>The transportation sector is certainly one of the main agent’s principals </span><span>and </span><span>has contributed to the increase in global air pollution. In Brazil, the large-scale</span><span> use of diesel for charge and passenger transport produces considerable air pollution in cities. The objectives of the study were to determine the concentrations of gas emissions (CO, NO and NO<sub>2<span><span></sub></span></span>), identify the chemical species that make up the particulates, from the exhaust of diesel vehicles and identify chemical species of particulates accumulated in air conditioning filters realized in the city of Campos dos Goytacazes located in the State of Rio de Janeiro. Thus, for the determination of the gas concentrations, electrochemical sensors were used and in the identification of chemical species, X-ray fluorescence spectroscopy was used. The results showed CO concentrations in the range of 173 to 880 ppmv, of NO in the range 52 to 240 ppmv and NO<span><span><span><span><span><span><sub>2<span><span></sub></span></span></span></span></span></span><span><span></span></span></span></span> in the range 6 to 252 ppmv in the vehicles exhaust, and chemical species of the particulates in the exhaust identified: Ca, Si, Fe, S, Ti, P, Zn, Sc and Mn. Furthermore, Ca, Si, Fe, S, Ti, P, Zn, Mn, K, Cl, Al, Pb, V, Cu, Sr, Br and Er were</span><span> </span><span>in the air conditioning system. The concentration of gases and particulates is increased by the presence of a large highway that runs through the city, with one intense flow of trucks and buses, which certainly contributes to the reduction of the region’s air quality.</span></span>展开更多
In this paper,the influence of aromatic content,one of main fuel properties,on diesel particulate emissions was studied at five steady-state operating conditions using a heavy-duty Perkins 4.236 engine.Detailed analys...In this paper,the influence of aromatic content,one of main fuel properties,on diesel particulate emissions was studied at five steady-state operating conditions using a heavy-duty Perkins 4.236 engine.Detailed analysis of the particulate showed the presence of biologically active polynuclear aromatic hydrocarbons(PAH) in high concentration.Unburnt PAH in liquid fuel are identified to be the dominant source of particulate PAH.Diesel particulates are also considered a potential health hazard because of the presence of PAH in the SOF of the particulates and some of these PAH are known to be carcinogenic.展开更多
Environmental impact assessment (EIA) and environmental management plan (EMP) is a statutory requirement for execution of new mining projects or for expansion of the operating projects. For this purpose, quantificatio...Environmental impact assessment (EIA) and environmental management plan (EMP) is a statutory requirement for execution of new mining projects or for expansion of the operating projects. For this purpose, quantification of blasting dust emission is required. This can be done by developing emission factors for blasting. The concept is similar to that of specific charge in blasting. For mining operations other than blasting, quantification of dust can be done using emis- sion factors. Emission estimation techniques are very limited for blasting. In this study, the emission factors were de- veloped by carrying out a detailed field study at one of the largest opencast coal mines of India in all four seasons. Da- ta on atmospheric and meteorological conditions were generated by installing sodar and automatic weather station at the mine site. Respirable dust samplers were installed for monitoring of the dust emitted during coal or overburden bench blasting. Emission factors for dust concentrations were developed in gram per cubic meter of rock excavated. The developed emission factors were used to estimate dust emissions for adjacent mines due to similarity in mining and meteorological conditions. Seasonal variations in moisture contents in benches, where dust was monitored, indicated the lowest emission factors in monsoon due to high moisture in the bench materials. Similar field studies were also conducted at another coalfield of India for two seasons. It was found that the emission factors are site-specific.展开更多
Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned par...Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less understood.Here,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were quantified.Atmospheric PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned PM.Total Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P<0.05).Regardless of particulate size,atmospheric PM-bound Hg had lower residual fractions(<21%)while higher HCl-soluble fractions(>40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.展开更多
The effects of continuously regenerating diesel particulate filter (CRDPF) systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investiga...The effects of continuously regenerating diesel particulate filter (CRDPF) systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units (CRDPF-1 and CRDPF-2) with different specifications were separately retrofitted to the engine running with European steady-state cycle (ESC). An electrical low pressure impactor (ELPI) was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate (RcR) of hydrocarbons (HC) and carbon monoxide (CO) across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio (A/F) at higher loads.展开更多
Experiments were conducted on a four-cylinder direct-injection diesel engine with 10% and 20% of the engine load taken up by fumigation ethanol injected into the air intake of each cylinder, to investigate the gaseous...Experiments were conducted on a four-cylinder direct-injection diesel engine with 10% and 20% of the engine load taken up by fumigation ethanol injected into the air intake of each cylinder, to investigate the gaseous, particulate mass (PM) emissions, and number concentration and size distribution of the engine under five engine loads at the maximum torque engine speed of 1800 r/min. The experimental results show that at low engine loads, the brake thermal efficiency (BTE) decreases with increase in fumigation ethanol; but at high engine loads, the BTE is not significantly changed by fumigation ethanol. Fumigation ethanol can effectively decrease in brake specific nitrogen oxides (BSNOx), particulate mass and number emissions but significantly increase in brake specific hydrocarbon (BSHC), brake specific carbon monoxide (BSCO) and proportion of BSNO/BSNO2. Also, the geometrical mean diameter of the particles (GMD) increases with increase in engine load but the diameter is not changed by fumigation ethanol in all cases.展开更多
This study assessed the effectiveness of three novel control technologies for particulate matter(PM) and volatile organic compound(VOC) removal from commercial meat cooking operations. All experiments were conduct...This study assessed the effectiveness of three novel control technologies for particulate matter(PM) and volatile organic compound(VOC) removal from commercial meat cooking operations. All experiments were conducted using standardized procedures at University of California, Riverside's commercial test cooking facility. PM mass emissions collected using South Coast Air Quality Management District(SCAQMD) Method 5.1, as well as a dilution tunnel-based PM method showed statistically significantly reductions for each control technology when compared to baseline testing(i.e., without a catalyst). Overall, particle number emissions decreased with the use of control technologies, with the exception of control technology 2(CT2), which is a grease removal technology based on boundary layer momentum transfer(BLMT) theory. Particle size distributions were unimodal with CT2 resulting in higher particle number populations at lower particle diameters. Organic carbon was the dominant PM component( 99%) for all experiments. Formaldehyde and acetaldehyde were the most abundant carbonyl compounds and showed reductions with the application of the control technologies. Some reductions in mono-aromatic VOCs were also observed with CT2 and the electrostatic precipitator(ESP) CT3 compared to the baseline testing.展开更多
A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes(E-wastes), including printed wiring boards(PWBs)and plastic casings. The generated particula...A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes(E-wastes), including printed wiring boards(PWBs)and plastic casings. The generated particulate matter(PM) of different particle sizes, carbon monoxide(CO) and carbon dioxide(CO_2) were determined, and the corresponding emission factors(EFs) were estimated. Finer particles with particle sizes of 0.4–2.1 μm accounted for78.9% and 89.3% of PM emitted by the pyrolytic processing of PWBs and plastic casings,respectively, and the corresponding EFs were 9.68 ± 4.81 and 18.49 ± 7.2 g/kg, respectively.The EFs of CO and CO_2 from PWBs and plastic casings were 55.9 ± 26.9 and 1182 ± 439 g/kg,and 133.6 ± 34.6 and 2827 ± 276 g/kg, respectively. Compared with other emission sources,such as coal, biomass, and traffic exhaust, the EFs of E-wastes were relatively higher,especially for PM. There were significant positive correlations(p < 0.05) of the initial contents of carbon and nitrogen in PWBs with the related EFs of PM, CO, and CO_2, while the correlations for plastic casings were insignificant. The EFs of CO of PWBs were significantly positively correlated with the corresponding EFs of PM and the parent polycyclic aromatic hydrocarbons(PAHs); however, the same result was not observed for plastic casings.展开更多
Particulate matter emissions from ammonia-based wet flue gas desulfurization(AmmoniaWFGD)systems are composed of a filterable particulate matter and a condensable particulate matter(CPM)portion.However,the CPM part ha...Particulate matter emissions from ammonia-based wet flue gas desulfurization(AmmoniaWFGD)systems are composed of a filterable particulate matter and a condensable particulate matter(CPM)portion.However,the CPM part has been ignored for a long time,which results in an underestim ation of the aerosol problems caused by Ammonia-WFGD systems.In our research,the characteristics of the CPM that emits from an Ammonia-WFGD system are investigated experimentally for the first time,with the US Environmental Protection Agency Method 202 employed as the primary measurement.The influences of some essential desulfurizing parameters are evaluated based on the experimental data.The results show that CPM contributes about 68.8%to the total particulate matter emission.CPM consists mainly of ammonium sulfates/sulfites,with the organic part accounting for less than 4%.CPM is mostly in the submicron fraction,about 71.1%of which originates from the NH3-H2O-SO2 reactions.The appropriate adjustments for the parameters of the flue gas and the desulfurizing solution can inhibit CPM formation to different extents.This indicates that the parameter optimizations are promising in solving CPM emission problems in Ammonia-WFGD systems,in which the pH adjustment alone can abate CPM emission by around 49%.The opposite variations of the parameters need attention because they can cause tremendous CPM emission increase.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 40371056)the Foundation for the Author of NationalExcellent Doctoral Dissertation of China (No. 200149)
文摘Measurements of the magnetic properties and total contents of Cu, Cd, Pb and Fe in 30 automobile emission particulate samples indicated the presence of magnetic particles in them. The values of frequency dependent susceptibility (Xfd) showed the absence of superparamagnetic (SP) grains in the samples. The IRM20mT (isothermal remanent magnetization at 20 mT) being linearly proportional to SIRM (saturation isothermal remanent magnetization) (R^2=0.901), suggested that ferrimagnetic minerals were responsible for the magnetic properties of automobile emission particulates. The average contents of Cu, Cd, Pb and Fe in automobile emission particulates were 95.83, 22.14, 30.58 and 34727.31 mg/kg, respectively. Significant positive correlations exist between the magnetic parameters and the contents ofPb, Cu and Fe. The magnetic parameters of automobile emission particulates reflecting concentration of magnetic particles increased linearly with increase of Pb and Cu content, showed that the magnetic measurement could be used as a preliminary index for detection of Pb and Cu pollution.
基金the National Park Service for financial assistance(contract P11AT30883/P11AC90465).
文摘Simulations from the Weather Research and Forecasting Model, inline coupled with chemistry, were used to examine the fate of particulate matter with diameter of 10 μm or less (PM10) in Glacier Bay, Alaska during the 2008 tourist season. The simulations demonstrated that mesoscale and synoptic scale weather systems affect the residence time of PM10, the magnitude of concentrations, and its transport in and out of Glacier Bay. Strong inversions exceeding 2 K (100 m)-1 cause notable trapping of pollutants from cruise-ship emissions, increasing PM10 concentrations up to 43% compared to days with cruise-ship visits without the presence of an inversion. Inversions occurred locally in Glacier Bay on 42% of the 124-day tourist season with an average lifetime of 9 h. Pollutants occasionally originated from outside the National Park when southerly winds advected pollutants from ship traffic in Icy Strait. Occasionally, orographically forced lifting over the Fairweather Mountains transported pollutants from the Gulf of Alaska into Glacier Bay. While hourly (daily) PM10 concentrations reached ~44 μg·m-3 (22 μg·m-3) in some areas of Glacier Bay, overall seasonal average PM10 concentrations were below 2 μg·m-3. Despite up to two cruise-ship visits per day, Glacier Bay still has pristine air quality. Surface and upper air meteorological state variables were evaluated through an extensive network of surface and radiosonde observations, which demonstrated that the model was able to capture the meteorological conditions well.
文摘Road transport exhaust emissions represent the main sources of atmospheric pollution in urban areas, due to the growing number of circulating vehicles and travelled distances. In order to reduce this pollution source, stricter emission standards are periodically set by governments through- out the world. Consequently, the concentrations of gaseous pollutants and particulate mass to be measured during type-approval tests of new vehicles are becoming progressively lower;moreover from 2011, diesel cars have to comply with particle number limit. In order to assess emission levels of different technology vehicles and investigate the use of a particulate number measurement technique at the exhaust of very low-emitting vehicles, an experimental activity was carried out on three in-use vehicles: a diesel car equipped with a particulate trap (DPF), a hybrid gasoline-elec- tric car and a bi-fuel passenger car fuelled with compressed natural gas (CNG). Cold and hot gaseous and particulate emission factors and fuel consumption were measured during the execution of real and regulatory driving cycles on a chassis dynamometer. Particulate was characterized in terms of mass only for the diesel car and of particle number for all vehicles. The emissions measured over the NEDC show that all three vehicles comply with their standard limits, except CO for CNG passenger car and NOx for diesel car. Cold start influences CO and HC emissions and fuel consumption for all the tested vehicles and in particular for the hybrid car. The real driving cycle is the most critical pattern for the emissions of almost all pollutants. During constant speed tests, the emissions of particles of hybrid car are an order of magnitude lower than those of the CNG car.
基金supported by the National Basic Research Program of China[973 program,grant number 2014CB441202]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA05100503]the National Natural Science Foundation of China[grant numbers 41021004,41475137,and 91544219]
文摘The nested-grid capability of the global chemical transport model GEOS-Chem, with a horizontal resolution of 1/4°× 5/16° (latitude x longitude), was used to identify the chemical species whose reductions made the largest contributions to decreases in PM2.s concentrations (fine particulate matter, diameter 〈 2.5μm, defined in this study as the sum of sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols) in Beijing during the 2014 Asia-Pacific Economic Cooperation (APEC) summit. A number of numerical experiments were carried out for the period 15 October-29 November 2014. The model reproduced the observed daily variations of concentrations of PM2.s and gas-phase species (carbon monoxide, nitrogen dioxide, and sulfur dioxide). Simulated PM2.s concentrations decreased by 55.9%-58.5% during the APEC period, compared to other periods in October and November 2014, which agreed closely with measurements. Sensitivity results showed that emissions control measures regarding nitrogen oxides and organic carbon over North China led to the largest reductions in PM2.s concentrations in Beijing during the APEC summit, which led to overall reductions in the PM2.5 concentration of Beijing by 5.7% and 4.6%, respectively. The control of ammonia emissions was found to be able to greatly reduce PM2.5 concentrations in the whole of North China during the APEC meeting.
文摘Transport fuels emit particulates of varying chemical nature and size. These particulates are known to cause respiratory problems of medical concern. The need to simulate the breathing characteristics of particulates generated from combustion events is very important in estimating the respiratory clearance of these particles. Consequently, this study examines the nature of particulate matter from the pyrolysis of a mixture Croton megalocarpus biodiesel and fossil diesel, and pure biodiesel. The study was explored at an optimum temperature of 600°C in an inert nitrogen environment at a contact time of 2 sec. Scanning electron microscope was used to examine the surface of the particulates. Multiple-Path Particulate Dosage (MPPD Ver. 3.04) model was used to determine the breathing phenomena of infants, teenagers and adults at different orientations. Co-pyrolytic Char particulates and pyrolytic croton thermal char were classified as ultrafine, PM0.03 and PM0.02 respectively. The MPPD model results indicated that ultrafine particles tend to be deposited in pulmonary regions more than head and trachea regions, due to high probability of diffusibiliy of ultrafine particles. It was noted that 8 years old exhibits a unique trend with high total deposition and poor respiratory clearance when compared to an adult of 21 years old.
文摘The study investigated the effects of four major particulate matter (PM) components namely sulphur, pulsar ash, carbon residue and ammonium components on the physical damage of sugarcane. A cyclone ambient kit tetra detector was used to quantify the components of the particulate matter at 2, 4, 6 and 8 km both in the windward and leeward sides of the power plant. This was done during the oncrop and offcrop season over a period of sixteen weeks. Eight sampling points were selected in an area of 2500 m2. Plant leaves were visually assessed for physical damage and the percentage of damage was noted. The results of the study were analyzed using SPSS version 16 and General Linear model-multivariate analysis to determine variation between the different means of components. Results showed that all PM components were only detected in the leeward side throughout the oncrop season and in the first two weeks of the offcrop. Ash and carbon deposition decreased with increasing distance. Ammonium components and sulphur were deposited only at 6 and 8 km. The percentage damage of the sugar cane was observed in the leeward side during the oncrop season. The physical damage caused by carbon and ash was observed in the 2 and 4 km distances whereas that caused by ammonium components and sulphur was observed in the 6 and 8 km distances.
文摘Emission factors (EFs) of particulate matter (PM) derived from mono and co-firing of Thai lignite and agricultural residues have been investigated. Two sampling methods for PM, total filtration (TF) and electrical low-pressure impactor (ELPI), were used together. The study is focused on the influence of fuel mass fraction, and of secondary air to total air; SA:TA on EFs of PM. The results have shown that EFs of PM in mass-basis given by TF method are 8.9, 5.3 and 8.1 mg/kgfuel, while 3.3, 2.7 and 3.3 mg/kgfuel when using ELPI, for firing at constant SA:TA (30%) of lignite, rice husk and bagasse, respectively. For co-firing with 30%SA of coal/rice husk, higher EFs of PM is observed. They are 7.17 and 10.9 mg/kgfuel (TF) for 40 and 70% rice husk share, respectively, or 4.18 and 5.19 mg/kgfuel (ELPI). However, lower PM emission; 1-3.3 mg/kgruel (TF) or 0.72-2.83 mg/kgfuel (ELPI) are obtained during co-firing of coal/rice husk with lower degree of air staging (i.e. 0-10% SA:TA). For the influence of oxygenation state, increasing of SA: TA leads to a low formation of ultrafine particles (Dp 〈 0.1 μm). Apart from PM, major gases (CO, NO, SO2) will be documented in this paper.
基金This research was supported by National Key Research and Development Program of China(2016YFB0600601)National Natural Science Foundation of China(51806144).
文摘Aiming at the problem of soot concentration measurement under ultra-low emission conditions,a forward small angle soot concentration measurement method is proposed.Taking a typical boiler emission of 0.1μm-3.0μm bimodal distribution soot as an object,the particle scatter simulation calculation under different parameters is carried out,and the influence of detection angle and particle size on the angular scatteringmeasurement of ultra-low emission soot is analyzed.The influence of detection angle and particle size on the angular scatteringmeasurement of ultra-lowemission soot is analyzed.Preferably,thewavelength of incident light is 650 nm,and the forward detection angle parameter is 15◦for the design of forward small angle soot concentration measurement system.An experimental system for measuring soot with standard concentration is built.Experiments of particle concentration measurement of 1.0μm and 3.0μm under ultra-low emission conditions are carried out.The results show that the average deviation of soot concentration measurement is less than 0.10 mg/m3 under the condition of ultra-low emission by using 15◦of forward detection,which provides an effective way for monitoring ultra-low emission soot concentration in coal-fired power plants.
基金Supported by Special Project for Research on Prevention and Control of Air Pollution from Fire Coal in 2018 of Ministry of Ecology and Environment of the People’s Republic of China(2018A030)
文摘From the perspective of development background,concepts and related policies of ultra-low emission,according to work practice,some issues and difficulties that need to be paid attention to in the environmental impact assessment of ultra-low-emission thermal power projects were discussed from the aspects of evaluation criteria,evaluation grade and scope,pollution control technical lines,environmental benefit accounting,and total emission control,and corresponding recommendations were put forward.
文摘Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit.The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines.The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm.About 93%of the particles are evaporated and absorbed when using a thermodenuder,and thus a large majority of the particles are volatile.Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.
基金the auspices of National Key Research and Development Program of China(No.2017YFC0212303,2017YFC0212304)National Natural Science Foundation of China(No.41771504)National Natural Science Foundation of Jilin Province(No.20200201214JC)。
文摘Domestic burning emits large amounts of pollutants into the ambient air due to incomplete and inefficient combustion, with significant impacts on indoor air quality and human health. Northeast China is one of the major contributors to domestic burning emissions in China;however, the high-resolution emissions inventories of domestic biomass and coal burning in Northeast China are lacked, which are needed to estimate the extent of its impact. In this study, we established a town-level emissions inventory of gaseous pollutants and particulate matter(PM) from domestic biomass and coal burning, based on per household consumption in each town in rural region of Northeast China. The results revealed that biomass burning was the major domestic burning source over the region in 2016. Domestic biomass burning is the major contributor to PM and volatile organic compounds(VOCs) emissions, while coal burning is the major contributor to SO2 emissions. High emissions intensities were concentrated around the cities of Harbin, Suihua, Changchun, Qiqihar, and Chifeng, each with emissions intensity for PM2.5 and VOCs of more than 2000 Mg per 27 km × 27 km grid cell. Additionally, there are three burning peaks(6-7 am, 12 pm and 4-7 pm) during both the heating(from October to April) and non-heating seasons(from May to September), due to cooking and heating. The burning peaks in the non-heating season were more notable than those in the heating season. These results suggest that the government should pay more attention to domestic biomass and coal burning in rural areas, in order to reduce pollutant emissions and control regional haze during the heating season.
文摘<span><span>The transportation sector is certainly one of the main agent’s principals </span><span>and </span><span>has contributed to the increase in global air pollution. In Brazil, the large-scale</span><span> use of diesel for charge and passenger transport produces considerable air pollution in cities. The objectives of the study were to determine the concentrations of gas emissions (CO, NO and NO<sub>2<span><span></sub></span></span>), identify the chemical species that make up the particulates, from the exhaust of diesel vehicles and identify chemical species of particulates accumulated in air conditioning filters realized in the city of Campos dos Goytacazes located in the State of Rio de Janeiro. Thus, for the determination of the gas concentrations, electrochemical sensors were used and in the identification of chemical species, X-ray fluorescence spectroscopy was used. The results showed CO concentrations in the range of 173 to 880 ppmv, of NO in the range 52 to 240 ppmv and NO<span><span><span><span><span><span><sub>2<span><span></sub></span></span></span></span></span></span><span><span></span></span></span></span> in the range 6 to 252 ppmv in the vehicles exhaust, and chemical species of the particulates in the exhaust identified: Ca, Si, Fe, S, Ti, P, Zn, Sc and Mn. Furthermore, Ca, Si, Fe, S, Ti, P, Zn, Mn, K, Cl, Al, Pb, V, Cu, Sr, Br and Er were</span><span> </span><span>in the air conditioning system. The concentration of gases and particulates is increased by the presence of a large highway that runs through the city, with one intense flow of trucks and buses, which certainly contributes to the reduction of the region’s air quality.</span></span>
文摘In this paper,the influence of aromatic content,one of main fuel properties,on diesel particulate emissions was studied at five steady-state operating conditions using a heavy-duty Perkins 4.236 engine.Detailed analysis of the particulate showed the presence of biologically active polynuclear aromatic hydrocarbons(PAH) in high concentration.Unburnt PAH in liquid fuel are identified to be the dominant source of particulate PAH.Diesel particulates are also considered a potential health hazard because of the presence of PAH in the SOF of the particulates and some of these PAH are known to be carcinogenic.
文摘Environmental impact assessment (EIA) and environmental management plan (EMP) is a statutory requirement for execution of new mining projects or for expansion of the operating projects. For this purpose, quantification of blasting dust emission is required. This can be done by developing emission factors for blasting. The concept is similar to that of specific charge in blasting. For mining operations other than blasting, quantification of dust can be done using emis- sion factors. Emission estimation techniques are very limited for blasting. In this study, the emission factors were de- veloped by carrying out a detailed field study at one of the largest opencast coal mines of India in all four seasons. Da- ta on atmospheric and meteorological conditions were generated by installing sodar and automatic weather station at the mine site. Respirable dust samplers were installed for monitoring of the dust emitted during coal or overburden bench blasting. Emission factors for dust concentrations were developed in gram per cubic meter of rock excavated. The developed emission factors were used to estimate dust emissions for adjacent mines due to similarity in mining and meteorological conditions. Seasonal variations in moisture contents in benches, where dust was monitored, indicated the lowest emission factors in monsoon due to high moisture in the bench materials. Similar field studies were also conducted at another coalfield of India for two seasons. It was found that the emission factors are site-specific.
基金supported by the Science and Technology Project of Guizhou Province(No.QKHJC[2020]1Y187)the National Natural Science Foundation of China(Nos.41265008,42007305,and 22166009)。
文摘Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less understood.Here,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were quantified.Atmospheric PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned PM.Total Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P<0.05).Regardless of particulate size,atmospheric PM-bound Hg had lower residual fractions(<21%)while higher HCl-soluble fractions(>40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.
基金supported by the National Natural Science Foundation of China (No. 40805053)
文摘The effects of continuously regenerating diesel particulate filter (CRDPF) systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units (CRDPF-1 and CRDPF-2) with different specifications were separately retrofitted to the engine running with European steady-state cycle (ESC). An electrical low pressure impactor (ELPI) was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate (RcR) of hydrocarbons (HC) and carbon monoxide (CO) across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio (A/F) at higher loads.
基金supported by the National Natural Science Foundation of China (Grant No. 50876065)the Research Grants Council of the HongKong SAR (Project No. PolyU 5139/07E)
文摘Experiments were conducted on a four-cylinder direct-injection diesel engine with 10% and 20% of the engine load taken up by fumigation ethanol injected into the air intake of each cylinder, to investigate the gaseous, particulate mass (PM) emissions, and number concentration and size distribution of the engine under five engine loads at the maximum torque engine speed of 1800 r/min. The experimental results show that at low engine loads, the brake thermal efficiency (BTE) decreases with increase in fumigation ethanol; but at high engine loads, the BTE is not significantly changed by fumigation ethanol. Fumigation ethanol can effectively decrease in brake specific nitrogen oxides (BSNOx), particulate mass and number emissions but significantly increase in brake specific hydrocarbon (BSHC), brake specific carbon monoxide (BSCO) and proportion of BSNO/BSNO2. Also, the geometrical mean diameter of the particles (GMD) increases with increase in engine load but the diameter is not changed by fumigation ethanol in all cases.
基金supported by the South Coast Air Quality Management District (SCAQMD) under contract 12174
文摘This study assessed the effectiveness of three novel control technologies for particulate matter(PM) and volatile organic compound(VOC) removal from commercial meat cooking operations. All experiments were conducted using standardized procedures at University of California, Riverside's commercial test cooking facility. PM mass emissions collected using South Coast Air Quality Management District(SCAQMD) Method 5.1, as well as a dilution tunnel-based PM method showed statistically significantly reductions for each control technology when compared to baseline testing(i.e., without a catalyst). Overall, particle number emissions decreased with the use of control technologies, with the exception of control technology 2(CT2), which is a grease removal technology based on boundary layer momentum transfer(BLMT) theory. Particle size distributions were unimodal with CT2 resulting in higher particle number populations at lower particle diameters. Organic carbon was the dominant PM component( 99%) for all experiments. Formaldehyde and acetaldehyde were the most abundant carbonyl compounds and showed reductions with the application of the control technologies. Some reductions in mono-aromatic VOCs were also observed with CT2 and the electrostatic precipitator(ESP) CT3 compared to the baseline testing.
基金supported by the Natural Science Foundation Committee of China(No.41390240)the National Basic Research Program of China(No.2014CB441101)
文摘A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes(E-wastes), including printed wiring boards(PWBs)and plastic casings. The generated particulate matter(PM) of different particle sizes, carbon monoxide(CO) and carbon dioxide(CO_2) were determined, and the corresponding emission factors(EFs) were estimated. Finer particles with particle sizes of 0.4–2.1 μm accounted for78.9% and 89.3% of PM emitted by the pyrolytic processing of PWBs and plastic casings,respectively, and the corresponding EFs were 9.68 ± 4.81 and 18.49 ± 7.2 g/kg, respectively.The EFs of CO and CO_2 from PWBs and plastic casings were 55.9 ± 26.9 and 1182 ± 439 g/kg,and 133.6 ± 34.6 and 2827 ± 276 g/kg, respectively. Compared with other emission sources,such as coal, biomass, and traffic exhaust, the EFs of E-wastes were relatively higher,especially for PM. There were significant positive correlations(p < 0.05) of the initial contents of carbon and nitrogen in PWBs with the related EFs of PM, CO, and CO_2, while the correlations for plastic casings were insignificant. The EFs of CO of PWBs were significantly positively correlated with the corresponding EFs of PM and the parent polycyclic aromatic hydrocarbons(PAHs); however, the same result was not observed for plastic casings.
基金supported by the National Key Research and Development Program of China(No.2016YFC0203703)the National Natural Science Foundation of China(Nos.51576039,51806107 and 21276049)+1 种基金the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1610)the Research Innovation Program for College Graduates of Jiangsu Province(No.KYLX16_0283)。
文摘Particulate matter emissions from ammonia-based wet flue gas desulfurization(AmmoniaWFGD)systems are composed of a filterable particulate matter and a condensable particulate matter(CPM)portion.However,the CPM part has been ignored for a long time,which results in an underestim ation of the aerosol problems caused by Ammonia-WFGD systems.In our research,the characteristics of the CPM that emits from an Ammonia-WFGD system are investigated experimentally for the first time,with the US Environmental Protection Agency Method 202 employed as the primary measurement.The influences of some essential desulfurizing parameters are evaluated based on the experimental data.The results show that CPM contributes about 68.8%to the total particulate matter emission.CPM consists mainly of ammonium sulfates/sulfites,with the organic part accounting for less than 4%.CPM is mostly in the submicron fraction,about 71.1%of which originates from the NH3-H2O-SO2 reactions.The appropriate adjustments for the parameters of the flue gas and the desulfurizing solution can inhibit CPM formation to different extents.This indicates that the parameter optimizations are promising in solving CPM emission problems in Ammonia-WFGD systems,in which the pH adjustment alone can abate CPM emission by around 49%.The opposite variations of the parameters need attention because they can cause tremendous CPM emission increase.