Chemical Composition of Aerosols from Kerosene Heaters Burning Jet Fuels

During the Persian Gulf conflict, some of the U.S. military personnel were diagnosed with a "mystery illness" or "Gulf War Syndrome." Environmental exposure included combustion products from unvented heaters in tents and may have contributed to the observed health effects. In our previous study, gases, including NO, CO, and SO 2 emitted from various heaters burning different fuels within an Army tent, were measured and analyzed. Aerosols from the heaters were characterized physically and chemically. This paper discusses chemical analyses of particulate emissions from the same heaters and fuels as presented in the previous study. The results were compared with gas analyses under the same conditions. In the elemental study, each heater and fuel produced large amounts of sulfur. Other elements, such as silica, aluminum, iron, etc., came from the ambient air. A few traces of lead were found in these analyses, but the source of the lead was unknown. Elemental and organic carbons were also detected. The rate of total carbon emission depended on heater and fuel types. The ion chromatography analysis revealed high emission rates of sulfate, and the results agreed with the elemental study. In addition to the SO = 4 , a high ammonium emission rate was detected. Compared to the SO = 4 and NH + 4 , the nitrate emission rate was relatively low. Considering all of the data, it appears that the carbon, SO = 4 , and NH + 4 from the fuels contributed to the pollutant in the tent.     

Characterization of Fine Particulate Emissions from Casting Processes

Fine particle (PM_2.5) emission rates and compositions from gray iron metal casting foundry were characterized for No-Bake molds poured at the Research Foundry located at Technikon, LLC (McClellan, CA). For each mold, PM_2.5 was collected for chemical analysis, and particle size distributions were measured by an Electrical Low Pressure Impactor (ELPI) to understand PM emissions during different part of the casting process. Molds prepared with phenolic urethane binders were poured with Class 30 gray cast iron at 1,427–1,480°C. PM_2.5 was collected from the pouring, cooling, and shakeout processes for each mold. Most of the PM_2.5 mass emitted from these processes was composed of carbonaceous compounds, including 37–67% organic carbon (OC) and 17–30% elemental carbon (EC). Oxides of aluminum (Al), silicon (Si), calcium (Ca), and iron (Fe) constituted 8–20% of PM_2.5 mass, and trace elements (e.g., K, Ti, Mn, Cu, Zn, and Pb) contributed 3–6%. Chemical abundances in PM were different between pouring and shakeout for each discrete mold. PM_2.5 mass emissions from pouring were 15–25% of the total from each discrete mold. Ultrafine particles (< 0.1 μm) contributed less than 1% of PM_2.5 mass, but nearly all of the particle numbers. Different mechanisms for pouring and shakeout result in variations in chemical abundances and particle size distributions. The highest PM_2.5 mass and number concentrations were observed when shakeout started. PM_2.5 size distributions in mass concentration during shakeout contained particles in the tail of coarse particles (1.6–2.5 μm) and a vapor condensation mode (0.65–1.6 μm). Flame conditions, vaporization, thermal decomposition of organic materials, and the variability of mold breakup during shakeout affect PM emission rates. A detailed chemical speciation for size-segregated PM samples at different process points needs to be conducted at full-scale foundries to obtain emission factors and source profiles applicable to emission inventories, source receptor modeling, and implementation of emission standards.     

上海某工业园区重点企业VOCs排放特征研究

依据USEPA TO-15方法,对某工业园区内4家重点企业开展VOCs监测。样品经冷阱预浓缩后,进入气相色谱分离,用质谱检测器进行检测。VOCs排放浓度在0.088～13.72 mg/m³之间,涂料生产企业（#2）排放VOCs浓度最高。芳香烃类是3家企业排放比例最高的VOCs组分。基于监测结果,依据光化学反应活性强、毒性与健康危害大等原则,确定VOCs优控污染物为苯、甲苯、二甲苯、1,3,5-三甲苯、乙苯、甲基异丁基酮、氯苯,为后续该工业园区大气在线监控网络设置提供科学依据。     

Modeling and Characterization of Air Emissions from Laboratory and Industrial Fluidized Beds

A fluidized bed model using several elutriation correlations was developed and tested against an operating fluidized bed used in a Fluidized Catalytic Cracker Unit (FCCU) and a 1:8.5 scale laboratory system. It was found that there was little variation between the emission rates predicted using different elutriation correlations, although the newly developed equations were slightly more accurate for the laboratory‐scale system. Although total emission rates were predicted with reasonable accuracy, the actual volatility and fluctuations seen in real fluidized beds emissions were not predicted. When the model was used to predict particle emission from the industrial FCCU, they preformed poorly, grossly overestimating the actual levels. It was determined that the attrition terms used in emission modeling were inappropriate and that the model preformed better without them, but still overestimated the actual emissions. This overestimation was greater in the industrial system compared with the smaller laboratory system. It was also found that the older elutriation terms were better for predicting industrial emissions compared with those of the smaller scale units.     

Emissions from a diesel-bioethanol blend in an automotive diesel engine

Diesel emissions have been measured from an automotive engine using anhydrous bioethanol blended with conventional diesel, with 10% ethanol in volume and no additives. The resulting emissions have been compared with those from pure diesel. A stationary engine test bed, together with the instrumentation for measuring the most stringent regulated emissions (nitric oxides, total hydrocarbons and particulate matter) and the particle size distributions, allowed to study the effect of this blend on the engine performance and emissions under five different steady state operating conditions, selected from the transient cycle for light duty vehicles established in the European Emission Directive 70/220. Both the consideration of the thermochemical properties of the tested fuels and the computations of a chemical equilibrium model were helpful for the results analysis. These results proved that the use of this renewable component provides a significant reduction on particulate emissions, with no substantial increase in other gaseous emissions, which makes it helpful for contributing, on the one hand, to fulfil the European compromise of using more than 5.75% biofuels in 2010, and on the other hand, to stop the increase in particulate emissions caused by transportation as a consequence of the unceasing dieselization.     

Exhaust Emissions from an Engine Fueled with Biodiesel from High-Oleic Soybeans

Biodiesel is a fuel comprising mono-alkyl esters of medium to long-chain fatty acids derived from vegetable oils or animal fats. Typically, engines operated on soybean-based biodiesel exhibit higher emissions of oxides of nitrogen (NOx) compared with petroleum diesel. The increase in NOx emissions might be an inherent characteristic of soybean oil’s polyunsaturation, because the level of saturation is known to affect the biodiesel’s cetane number, which can affect NOx. A feedstock that is mostly monounsaturated (i.e. oleate) helps to balance the tradeoff between cold flow and oxidative stability. Genetic modification has produced a soybean event, designated 335-13, with a fatty acid profile high in oleic acid (>85%) and with reduced palmitic acid (<4%). This high-oleic soybean oil was converted to biodiesel and run in a John Deere 4045T 4.5-L four-stroke, four-cylinder, turbocharged direct-injection diesel engine. The exhaust emissions were compared with those from conventional soybean oil biodiesel and commercial No. 2 diesel fuel. There was a significant reduction in NOx emissions (α = 0.05) using the high-oleic soybean biodiesel compared with regular soybean oil biodiesel. No significant differences were found between the regular and high-oleic biodiesel for unburned hydrocarbon and smoke emissions.     

Toxicologic and Physicochemical Characterization of High-Temperature Combustion Emissions

Particles and combustion gases produced by two different high-temperature combustors, which burned pulverized coal and a No. 2 fuel oil-fly ash slurry, respectively, at adiabatic flame temperatures greater than 2400 K, were characterized. Effluent samples were taken at locations along the product gas stream and within the stack. Measurements of the particle size distributions, number concentrations, and gas species concentrations were made. The toxicity and mutagenicity of the effluent particles were determined. A large number of submicrometer particles were found in both cases of high-temperature combustion. The product emissions differed significantly in their particle size distribution and final chemical composition from those of conventional combustion systems having lower combustion temperatures.     

Procedures for Chemical Characterization of Sized Particles in Stationary Source Emissions

Methodology for the determination of the chemical composition of sized particulate emissions from sources is described. Emphasis is on the determination of the elemental content with X-ray fluorescence analysis (XRF) the principal analytical technique employed. Devices and procedures developed for the collection of sized particles from stationary sources are presented. Included are a sampler for size classification of submicrometer particles based on diffusion and a special in-stack cascade impactor that was developed to collect samples compatible for XRF analysis. Representative data on the chemical content of sized emission samples collected with these devices at several stationary sources are discussed.     

粗酚中酚及同系物测定用共沸剂—煤油二甲苯中煤油清洗及精制方法

哈尔滨气化厂生产的粗酚是煤气化后生成的副产品，它的分析采用YB／T5080－1993规定之测定方法。但在YB／T5080－93分析方法中，共沸混全物煤油－二甲苯中煤油的清洗及精制过程写的很粗略，怎样省时、省力、又经济地达到清洗、精制目的并取得分析的良好效果，很值得我们讨论。     

Characterization of Methane Emissions from Rice Fields in Asia. III. Mitigation Options and Future Research Needs

Methane (CH₄) emissions from rice fields were determined using automated measurement systems in China, India, Indonesia, Thailand, and the Philippines. Mitigation options were assessed separately for different baseline practices of irrigated rice, rainfed, and deepwater rice. Irrigated rice is the largest source of CH₄ and also offers the most options to modify crop management for reducing these emissions. Optimizing irrigation patterns by additional drainage periods in the field or an early timing of midseason drainage accounted for 7–80% of CH₄ emissions of the respective baseline practice. In baseline practices with high organic amendments, use of compost (58–63%), biogas residues (10–16%), and direct wet seeding (16–22%) should be considered mitigation options. In baseline practices using prilled urea as sole N source, use of ammonium sulfate could reduce CH₄ emission by 10–67%. In all rice ecosystems, CH₄ emissions can be reduced by fallow incorporation (11%) and mulching (11%) of rice straw as well as addition of phosphogypsum (9–73%). However, in rainfed and deepwater rice, mitigation options are very limited in both number and potential gains. The assessment of these crop management options includes their total factor productivity and possible adverse effects. Due to higher nitrous oxide (N₂O) emissions, changes in water regime are only recommended for rice systems with high baseline emissions of CH₄. Key objectives of future research are identifying and characterizing high-emitting rice systems, developing site-specific technology packages, ascertaining synergies with productivity, and accounting for N₂O emissions.     

Characterization of Methane Emissions from Rice Fields in Asia. I. Comparison among Field Sites in Five Countries

The Interregional Research Program on Methane Emissions from Rice Fields established a network of eight measuring stations in five Asian countries. These stations covered different environments and encompassed varying practices in crop management. All stations were equipped with a closed chamber system designed for frequent sampling and long-term measurements of emission rates. Even under identical treatment--e.g., continuous flooding and no organic fertilizers--average emission rates varied from 15 to 200 kg CH₄ ha^–1 season^–1. Low temperatures limited CH₄ emissions in temperate and subtropical stations such as northern China and northern India. Differences observed under given climates, (e.g., within the tropics) indicated the importance of soil properties in regulating the CH₄ emission potential. However, local variations in crop management superseded the impact of soil- and climate-related factors. This resulted in uniformly high emission rates of about 300 kg CH₄ ha^–1 season^–1 for the irrigated rice stations in the Philippines (Maligaya) and China (Beijing and Hangzhou). The station in northern India (Delhi) was characterized by exceptionally low emission rates of less than 20 kg CH₄ ha^–1 season^–1 under local practice. These findings also suggest opportunities for reducing CH₄ emission through a deliberate modification of cultural practice for most irrigated rice fields.     

Volatile Emissions from an Odorous Plant in Response to Herbivory and Methyl Jasmonate Exposure

Induced volatile terpenes have been commonly reported among diverse agricultural plant species, but less commonly investigated in odorous plant species. Odorous plants synthesize and constitutively store relatively large amounts of volatiles, and these may play a role in defense against herbivores. We examined the effect of herbivory and methyl jasmonate (MeJA) exposure on the release of volatile organic compounds (VOCs) in the marsh elder, Iva frutescens, which contains numerous constitutive VOCs, mainly mono- and sesquiterpenes. Our specific goal was to test for the presence of inducible VOCs in a naturally occurring plant already armed with VOCs. The abundant, native specialist leaf beetle Paria aterrima was used in herbivore induction trials. VOCs were sampled from herbivore wounded and unwounded, and from MeJA treated and untreated I. frutescens. Total VOC emissions were significantly greater in response to herbivory and MeJA treatment compared to unwounded controls. Herbivore wounding caused a substantial shift in the emission profile (42 VOCs from wounded, compared to 8 VOCs from unwounded I. frutescens), and MeJA had a similar yet less substantial influence on the emission pattern (28 VOCs from MeJA treated compared to 8 VOCs from untreated I. frutescens). Constitutive VOC emissions predominated, but some VOCs were detected only in response to herbivory and MeJA treatment, suggesting de novo synthesis. Several VOCs exhibited a delayed emission profile in contrast to the rapid release of constitutive VOCs, and principal components analysis revealed they were not associated with constitutive emissions. While I. frutescens contains many constitutive VOCs that are released immediately in response to herbivory, it also produces novel VOCs in response to feeding by the specialist P. aterrima and MeJA treatment.     

Emissions from a diesel car during regeneration of an active diesel particulate filter

The California Air Resources Board (CARB) and the Joint Research Center of the European Commission (JRC) have collaborated on emissions testing of a light duty diesel vehicle, which is Euro 4 compliant and comes equipped with a diesel particulate filter (DPF). The California testing included an investigation of the regeneration of the DPF over cruise conditions and NEDC test cycles. DPF regeneration is caused by the buildup of soot in the filter, and for the present test vehicle the regeneration process is assisted by a fuel borne catalyst. Regulated exhaust emissions increased substantially during the regeneration events; however, PM emissions levels were below California LEVII emissions standards. There was a very large increase of volatile particles between 5 and 10 nm, and these volatile particles were generated during all of the observed regeneration events. It appears that the particle number instruments that use the PMP methodology do not capture the PM mass increase during DPF regeneration; however, for one regeneration event there was an apparent large increase in solid particles below the PMP size limit. The PM mass increase associated with regeneration appears to be due to semi-volatile particles collected on filters. During the testing, the regeneration events exhibited considerable variations in the time for regeneration as well as the amount of PM emissions. From this investigation, several questions have been posed concerning the emission of very small (<20 nm) volatile and solid particles during DPF regeneration that need further investigation.     

外取热器的制造工艺

介绍了外取热器的加工、制造和安装工艺过程     

Single Particle Characterization of Automobile and Diesel Truck Emissions in the Caldecott Tunnel

Individual aerosol particles emitted from light-duty vehicles (LDV) and heavy-duty vehicles (HDV) were sampled in the Caldecott Tunnel (Berkeley, CA) using an aerosol time-of-flight mass spectrometer (ATOFMS). This instru ment determines both size and composition information of individual particles in real time. From the composition of individual particles, in conjunction with knowledge of the traffic patterns in the Caldecott Tunnel, information about the source of the particles can be determined. Based upon chemical composition, three main types of particles were detected: particles with significant mass spectral signal due to polycyclic aromatic hydrocarbons (PAH), elemental carbon (soot) particles, and inorganic particles containing substantial signal due to ions includ ing Al⁺, Ca⁺, Fe⁺, Ba⁺ and BaO⁺. Preliminary analysis of these classes shows that they encompass 61.4%, 10.3%, and 11.0%, respectively, of the total number of particles sampled with the ATOFMS instrument in 3 h, heavy traffic sampling periods, in an LDV-only bore of the tunnel. They represent 57.4%, 11.8%, and 18.0%, respectively, of the total number of particles sampled with the ATOFMS instrument in a 3 h sampling period in a mixed traffic (HDV and LDV) bore of the tunnel.     

吡啶从硝酸介质中萃取铀(VI)的研究

研究了新萃取剂吡啶从硝酸介质中萃取铀的机理。考察水相硝酸浓度、萃取剂浓度、盐析剂硝酸钠以及振荡时间和温度对萃取分配比的影响 ,确定了萃合物的组成。求得萃取硝酸铀酰过程的平衡常数及反应的热力学函数。同时研究了相比的影响 ,以及稀释剂的影响。发现吡啶萃取能力在不同稀释剂中由弱到强的顺序为 :四氯化碳、氯仿、苯、甲苯、环己烷、煤油。     

吡啶从硝酸介质中萃取铀(Ⅵ)的研究

研究了新萃取剂吡啶从硝酸介质中萃取铀的机理。考察水相硝酸浓度、萃取剂浓度、盐析剂硝酸钠以及振荡时间和温度对萃取分配比的影响，确定了萃合物的组成。求得萃取硝酸铀酰过程的平衡常数及反应的热力学函数。同时研究了相比的影响，以及稀释剂的影响。发现吡啶萃取能力在不同稀释剂中由弱到强的顺序为：四氯化碳、氯仿、苯、甲苯、环己烷、煤油。     

细木工板中甲醛释放特征及规律

采用环境测试舱模拟室内环境,测量细木工板中甲醛的释放浓度,考察细木工板结构、温度、相对湿度和空气交换率对甲醛释放的影响,分析细木工板中甲醛气体扩散机理,并建立了灰色预测模型对细木工板中甲醛释放峰值后的过程进行模拟. 结果表明,细木工板中甲醛散发通道主要为端面,端面的甲醛释放量是平面的3倍;细木工板中甲醛气体扩散过程分为3个阶段(初始快速释放、稳定释放和长期缓速释放);空气交换率对细木工板中甲醛释放率影响不大;相对湿度和温度升高,细木工板中甲醛释放率也增大;预测模型的预测数据与实验数据吻合较好,平均相对误差率仅为3.717%,适合进行长期预测.     

Prediction of NOx Emissions from a Transiently Operating Diesel Engine Using an Artificial Neural Network

For an adequate control of the reductant flow in selective catalytic reduction of NO_x in diesel exhaust, a tool has to be available to accurately and quickly predict the engine's NO_x emission. For these purposes, elaborate computer models and expensive NO_x analyzers are not feasible. The application of a neural network is proposed instead. Measurements were performed on a transient operating diesel engine. One part of the data was used to train the network for NO_x emission prediction, the other part was used to test. The average absolute deviation between the predicted and measured NO_x emission is 6.7 %. The reductant buffering capacity of the deNOx catalyst will diminish the effect of the deviation on the overall NO_x removal efficiency. The high accuracy of the neural network predictions, combined with the short computation times (0.2 ms/data point), makes the neural network a very promising tool in automotive NO_x control.