济南市柴油型移动源排放颗粒物中碳组分特征和排放量估算

为了识别济南市柴油型移动源排放颗粒物中碳组分特征,采用稀释通道采样器于2021年采集了柴油货车和工程机械尾气排放颗粒物,并对汽油车尾气一并采集对比,分析了尾气排放颗粒物质量浓度和其中的碳组分。结果表明,柴油型移动源排放颗粒物质量浓度明显高于汽油车,且以细颗粒物为主,PM_2.5/PM₁₀数值几乎接近于1.0,其中柴油货车排放颗粒物质量浓度高于工程机械,且随车型增大排放颗粒物质量浓度增大,重型柴油载货车排放PM_2.5和PM₁₀质量浓度最大,分别为4.56×10⁴μg·m^-3和4.71×10⁴μg·m^-3。柴油货车PM_2.5和PM₁₀排放因子范围分别为8.90-21.8 mg·km^-1和9.40-22.5 mg·km^-1,工程机械中破碎机颗粒物排放因子略大于挖掘机,破碎机PM_2.5和PM₁₀     

武汉秋冬季大气PM2.5中多环芳烃的分布特征及来源

采集了2011—2012年武汉市工业区、交通区和植物园的3个功能区的秋冬2季大气PM2.5样品,采用超声提取预处理和GC/MS分析检测了PM2.5中27种PAHs,探讨了其时空分布特征,然后运用主成分分析/多元线性回归法解析了PAHs的来源.结果表明:PAHs的质量浓度范围为24.705~112.490 ng·m-3,PAHs的质量浓度分布呈现出工业区>交通区>植物园的规律;冬季PAHs质量浓度高于秋季等特征.不同环数PAHs质量浓度呈现出规律变化为:5环>4环>2-3环>6-7环,4环、5环的 PAH 含量比例高表明机动车尾气和煤燃烧排放是主要排放源.不同功能区化合物的比值指示来源略有不同,但总体指明了武汉主要污染源来自燃煤和机动车尾气的排放.源解析结果显示,工业区的污染源主要来自于燃煤,其贡献率为55%,其次为汽油燃烧、柴油燃烧、焦炉和轻质油燃烧.在交通区中,车辆尾气排放(34%)和天然气燃烧(25%)的贡献较大,其次是烹饪、燃煤及木材燃烧.植物园对照区的主要污染源分别是木材燃烧、燃煤、天然气燃烧、车辆排放和烹饪,其中木材燃烧(46%)的贡献最大.     

成都市冬季PM_(2.5)中碳组分污染特征及来源解析

为研究成都市冬季PM_(2.5)中碳组分的污染特征和来源,于2019年12月7—28日在成都市进行PM_(2.5)的采集,并利用热光碳分析仪和元素分析仪-同位素质谱仪分别测定了样品中有机碳(OC)和元素碳(EC)的质量浓度以及碳同位素的组成特征。结果表明,成都市PM_(2.5)、OC和EC的平均质量浓度分别为98.23、14.50、2.19μg·m~(-3);OC和EC的相关性较高(相关系数为0.80),表明OC和EC可能具有一致的来源,也有可能是具有较高的混合程度;OC/EC比值大于2.0,表明成都市冬季有二次有机碳(SOC)的形成,且SOC/OC的比值为34.48%;主成分分析结果显示,生物质燃烧、燃煤和汽油车尾气尘混合源是成都市冬季PM_(2.5)碳组分的主要来源,贡献率为59.68%;其次是柴油车尾气尘,贡献率为22.40%;碳同位素组成结果显示,成都市冬季PM_(2.5)碳组分的来源与汽油车尾气排放相关性最强,其次为C3植物燃烧;通过IsoSource模型软件进行计算,可知不同时期各污染源的贡献比例均呈现出汽油车尾气排放C3植物燃烧柴油车尾气排放燃煤C4植物燃烧地质源(农业土壤、扬尘)的规律,但相较于清洁期来说,污染期的汽油车尾气排放和C3植物燃烧污染源所占比例增大。研究结果可为成都市大气污染治理提供理论指导。     

柴油发动机尾气中3,4-苯并芘的测定

随着我国以柴油机为动力的车辆设备的逐年增加,柴油的消耗量在不断地上升,柴油机尾气中排放出具有致癌毒性的3,4-苯并芘(简称BaP)的量也在日益增多,造成了对环境的严重污染。日本、美国以及其他许多国家对这种污染开展了研究。我们对国产6130-Q型柴油机进行了台架实验,用带荧光检测器的高压液相色谱,研究了柴油机尾     

汽油尾气对人肺腺癌A549细胞的氧化损伤效应研究

为研究汽油燃烧汽车尾气(简称汽油尾气)的氧化损伤效应及其可能的毒作用机制,以人肺腺癌A549细胞为研究对象,采用MTT试验测试汽油尾气对细胞的毒性作用;通过测定细胞内超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)活性了解细胞在汽油尾气作用下抗氧化水平的改变;并用彗星试验检测汽油尾气对细胞DNA氧化损伤及修复的影响．结果显示汽油尾气在浓度≥0．0625L·mL-1时即显示出明显的细胞毒性;汽油尾气作用下A549 细胞SOD及GSH-Px活性均下降,在一定的浓度范围内与对照组比较有统计学差异(p<0．05)．汽油尾气可诱导 A549细胞不同程度的DNA氧化损伤,且细胞拖尾率和DNA迁移长度均随着汽油尾气浓度的增加而增加;损伤后 A549细胞修复发生较快,3小时内基本修复完全．提示汽油尾气具有明显的细胞毒性作用,可影响A549细胞抗氧化酶活性,并可导致DNA的氧化损伤．     

生物质燃料高温燃烧过程中有害气体的排放

利用FACTSAGE软件定量计算麦秆、玉米秆和稻草3种生物质燃料在燃烧过程中PM2.5的排放情况,探究反应过程中氧含量、温度等对燃烧尾气中HF、HCl、SOx和NO排放的影响,从而确定适合生物质燃料燃烧的条件。结果表明:由于秸秆F、Cl含量较多,燃烧反应后会产生大量HCl和HF。为了控制生物质燃料中F、Cl化合物的产生,燃烧温度应控制在1 000~1 100℃;氧含量应选择正常空气氧含量,氧含量过低,燃烧尾气中会生成较多的氨及氢氧化物;氧含量过高,则会生成较多的硫氧化物和氮氧化物。     

城市在用CNG汽车排放研究

通过车载实验,怠速法检测、简易工况法检测数据评价分析等方法,研究了重庆市在用CNG车辆排放情况,比较了CNG车与同类型汽油、柴油车尾气污染物排放情况。研究发现,目前CNG在用车并非绝对的环保汽车,其中在NOx的排放上,CNG车排放高于同类型汽油、柴油车0．03—14倍;在CO、THC的排放上,不同测试工况下CNG汽车表...     

化学工业区周边土壤中多环芳烃含量、来源及健康风险评估

于2015年6月采集日照市岚山化工园区和临沂市罗庄华宇电解铝厂周围土壤样品,分析了16种多环芳烃(PAHs)的含量和组成,研究了距化工区不同距离的土壤中PAHs含量和组成的变化、来源及健康风险.结果表明,岚山化工园区周围土壤中PAHs总含量(∑_(16)PAHs)(2764.2—3435.9μg·kg~(-1))略高于华宇电解铝厂周边土壤中∑_(16)PAHs(2729.7—3047.5μg·kg~(-1)),均达到重度污染.两化工厂周边土壤中各环数PAHs所占比例大小顺序均为4环5环3环2环和6环,但各PAHs化合物的组成存在差异.距化工区越远,土壤中∑_(16)PAHs含量越低,但各环数PAHs含量变化不一致.同分异构体比值法结果表明,两化工厂PAHs主要来源是燃煤和石油燃烧.正定矩阵因子分解法表明,岚山化工园区周围土壤PAHs的来源中燃煤源占36%,汽油和柴油燃烧源占21.6%,生物质燃烧源占19.1%,石油源和焦炭燃烧混合源占19.3%.华宇电解铝厂周围土壤PAHs的来源中燃煤源占33.5%,汽油燃烧源占24.8%,柴油燃烧源占31.4%,生物质燃烧源占10.3%.岚山化工园区周围土壤PAHs来源中燃煤源所占比例高于华宇电解铝厂,汽油和柴油燃烧源所占比例低于华宇电解铝厂.岚山化工园区和华宇电解铝厂周边土壤中PAHs的总Ba P_(eq)平均值分别为326.7μg·kg~(-1)和441.1μg·kg~(-1),均低于加拿大土壤质量指导值600μg·kg~(-1).健康风险评估表明,华宇电解铝厂总ILCRs值(3.9×10~(-6)—6.0×10~(-6))高于岚山化工园区(2.9×10~(-6)—4.5×10~(-6)).两化工厂周围土壤总ILCRs值大于1×10~(-6),均存在潜在的致癌风险.     

2009年北京市苯系物污染水平和变化特征

采用Tenax-TA/吸附热解吸、光离子化气相色谱法(GC-PID)对北京市大气中苯系物(BTEX)的小时平均浓度进行了为期1年的观测.结果表明,苯、甲苯、乙苯、间/对-二甲苯和邻二甲苯的年平均浓度分别为:4.43、7.03、2.27、4.18和2.06μg.m-3.苯系物之间具有很好的同源性,其浓度存在明显的日变化和季节变化,这些变化特征与交通尾气排放、采暖期化石燃料燃烧、光化学反应活性等密切相关.苯与甲苯特征比值(B/T)的分析表明,交通尾气排放是北京市大气中苯系物的主要来源,冬季和早春采暖期化石燃料燃烧也是北京市大气中BTEX的重要来源之一.乙苯与二甲苯比值(E/X)的季节变化为:夏季>春季>秋季>冬季,与北京市大气光化学反应活性季节变化趋势相似.2009年北京夏季总苯系物的平均浓度比2004年夏季减少了2/3,表明北京市政府为改善空气质量所采取的一系列控制措施十分有效.     

环境科技简讯

到2005年时,化石能源的利用将占全世界能源的90%.从天然气价格低廉的特点来考虑,利用天然气制取甲醇及合成燃料将是可以发展的代用碳氢燃料;这种燃料很可能成为汽油的竞争者.此外,利用压缩的或液化的天然气代替汽油将具有良好的前景.     

Impacts of methanol fuel on vehicular emissions: A review

● Methanol effectively reduces CO, HC, CO₂, PM, and PN emissions of gasoline vehicles. ● Elemental composition of methanol directly affects the reduction of emissions. ● Several physicochemical properties of methanol help reduce vehicle emissions. The transport sector is a significant energy consumer and a major contributor to urban air pollution. At present, the substitution of cleaner fuel is one feasible way to deal with the growing energy demand and environmental pollution. Methanol has been recognized as a good alternative to gasoline due to its good combustion performance. In the past decades, many studies have investigated exhaust emissions using methanol-gasoline blends. However, the conclusions derived from different studies vary significantly, and the explanations for the effects of methanol blending on exhaust emissions are also inconsistent. This review summarizes the characteristics of CO, HC, NO_x, CO₂, and particulate emissions from methanol-gasoline blended fuels and pure methanol fuel. CO, HC, CO₂, particle mass (PM), and particle number (PN) emissions decrease when methanol-blended fuel is used in place of gasoline fuel. NO_x emission either decreases or increases depending on the test conditions, i.e., methanol content. Furthermore, this review synthesizes the mechanisms by which methanol-blended fuel influences pollutant emissions. This review provides insight into the pollutant emissions from methanol-blended fuel, which will aid policymakers in making energy strategy decisions that take urban air pollution, climate change, and energy security into account.     

A comparative study of particle size distribution from two oxygenated fuels and diesel fuel

Oxygenated fuels are known to reduce particulate matter (PM) emissions from diesel engines. In this study, 100% soy methyl ester (SME) biodiesel fuel (B100) and a blend of 10% acetal denoted by A-diesel with diesel fuel were tested as oxygenated fuels. Particle size and number distributions from a diesel engine fueled with oxygenated fuels and base diesel fuel were measured using an Electrical Low Pressure Impactor (ELPI). Measurements were made at ten steady-state operational modes of various loads at two engine speeds. It was found that the geometric mean diameters of particles from SME and Adiesel were lower than that from base diesel fuel. Compared to diesel fuel, SME emitted more ultra-fine particles at rated speed while emitting less ultra-fine particles at maximum speed. Ultra-fine particle number concentrations of A-diesel were much higher than those of base diesel fuel at most test modes.     

Polynuclear aromatic compounds in kerosene,diesel and unmodified sunflower oil and in respective engine exhaust particulate emissions

Polynuclear aromatic compounds (PAC) were characterized in diesel fuel, kerosene fuel and unmodified sunflower oil as well as in their respective engine exhaust particulates. Diesel fuel was found to contain high amounts of different PAC, up to a total concentration of 14,740?ppm, including carbazole and dibenzothiophene, which are known carcinogens. Kerosene fuel was also found to contain high amounts of different PAC, up to a total concentration of 10,930?ppm, consisting mainly of lower molecular weight (MW) naphthalene and its alkyl derivatives, but no PAC component peaks were detected in the unmodified sunflower oil. Engine exhaust particulates sampled from a modified one-cylinder diesel engine running on diesel, kerosene and unmodified sunflower oil, respectively, were found to contain significantly high concentrations of different PAC, including many of the carcinogenic ones, in the soluble organic fraction (SOF). PAC concentrations detected at the exhaust outlet indicated that most of the PAC that were present in diesel and kerosene fuels before the test runs got completely burnt out during combustion in the engine whereas some new ones were also formed. The difference between the character and composition of PAC present in the fuels and those emitted in the exhaust particulates indicated that exhaust PAC were predominantly combustion generated. High amounts of PAC, up to totals of 52,900 and 4830?µg?m^?3 of burnt fuel, in diesel and kerosene exhaust particulates, respectively, were detected in the dilution tunnel when the exhaust emissions were mixed with atmospheric air. Significant amounts of PAC were also emitted when the engine was run on unmodified sunflower oil with a total concentration of 17,070?µg?m^?3 of burnt fuel detected in the dilution tunnel. High proportions of the combustion-generated PAC determined when the engine was run on diesel, kerosene and unmodified sunflower, respectively, consisted of nitrogen-containing PAC (PANH) and sulphur-containing PAC (PASH).     

Effects of ambient temperature on regulated gaseous and particulate emissions from gasoline-, E10- and M15-fueled vehicles

• Emissions from two sedans were tested with gasoline, E10 and M15 at 30°C and -7°C. • As the temperature decreased, the PM, PN and BC emissions increased with all fuels. • Particulate emissions with E10 and M15 were more sensitive to the temperature. • The PN and BC generated during cold start-up dominated those over the WLTC. Ambient temperature has substantial impacts on vehicle emissions, but the impacts may differ between traditional and alcohol gasolines. The objective of this study was to investigate the effects of temperature on gaseous and particulate emissions with both traditional and alcohol gasoline. Regulated gaseous, particle mass (PM), particle number (PN) and black carbon (BC) emissions from typical passenger vehicles were separately quantified with gasoline, E10 (10% ethanol and 90% gasoline by volume) and M15 (15% methanol and 85% gasoline by volume) at both 30°C and -7°C. The particulate emissions with all fuels increased significantly with decreased temperature. The PM emissions with E10 were only 48.0%–50.7% of those with gasoline at 30°C but increased to 59.2%-79.4% at -7°C. The PM emissions with M15 were comparable to those with gasoline at 30°C, but at -7°C, the average PM emissions were higher than those with gasoline. The variation trend of PN emissions was similar to that of PM emissions with changes in the fuel and temperature. At 30°C, the BC emissions were lower with E10 and M15 than with gasoline in most cases, but E10 and M15 might emit more BC than gasoline at -7°C, especially M15. The results of the transient PN and BC emission rates show that particulate emissions were dominated mainly by those emitted during the cold-start moment. Overall, the particulate emissions with E10 and M15 were more easily affected by ambient temperature, and the advantages of E10 and M15 in controlling particulate emissions declined as the ambient temperature decreased.     

Tiefentschwefelte Kraftstoffe

In recent years, much attention has been given to the desulphurization of fuels like diesel oil and gasoline, since exhaust gases containing SOx cause air pollution and acid rain. Moreover, a lower sulphur content of fuels would allow the use of new engines and catalytic systems for the reduction of CO, particle and NOx-emissions, and a more efficient fuel consumption. The S-level in fuels is presently limited in Germany for gasoline and diesel oll to 150 ppm and 350 ppm, respectively. In 2005 the level will be decreased Europe-wide for all vehicle-fuels down to 50 ppm; in some countries, fuels are or will be on the market with even less sulphur. The current technology of hydrodesulphurization (heterogeneous, catalyzed hydrorreating of organic sulphur compounds) can desulphurize quite adequately down to today’s S-level. The process, however, is limited for the production of ultra-low sulphur fuels, and the expenses (pressure, reactor size, investment costs, energy consumption, specific active catalysts) are high to meet future requirements. alternative processes, which are not limited to hydrotreating, are therefore desirable. Beside an overview about hydrotreating, this paper presents two quite different alternatives: Extraction of sulphur compounds by ionic liquids and the synthetic production of S-free fuels from natural gas by Fischer-Tropsch-synthesis. Ionic liquids (ILs) are low melting (<100°C) salts which represent a new class of non-molecular, ionic solvents. In the experiments presented, extraction of model diesel oils (dibenzothiophene and dodecanthiol in n-dodecane) as well as of a real predesulphurized diesel oil (with about 400 ppm S) were investigated. The results show the excellent and selective extraction properties of ILs for organic sulphur compounds, especially with regard to those compounds which are very difficult to remove by common hydrodesulphurization. As expected, the desulphurization by extraction is much more complicated in case of real diesel oil (compared to a model oil) due to its complex chemical composition including many different sulphur compounds and other impurities like organic nitrogen and metal-compounds. Nevertheless, the results with pre-desulphurized diesel oil are also very promising. So, extraction of sulphur components by ILs is a new approach for deep desulphurization of diesel oil. The application of very mild process conditions (low pressure and temperature) in comparison to traditional hydrotreating is an additional advantage of this new concept. An alternative to today’s fuels based on crude oil is the production of gasoline and diesel oil from natural gas (or other fossil fuels like coal) by Fischer-Tropsch-synthesis (FTS). The products like diesel oil are completely free of sulphur and other impurities like nitrogen and metal compounds. Although several FTS-processes have been investigated and developed, and some processes are already running on a technical scale, a real breakthrough was not obtained up to now. The production costs of these capital-intensive processes are probably above the breakeven point, at least at today’s oil price. In this paper, a ‘lowcost’ process is discussed, which is based on nitrogen-rich syngas. In contrast to classical FTS-processes with nitrogen-free syngas, the investment costs are probably lower: The syngas is produced by partial oxidation with ait, which eliminates the need of an air separation plant, while a process with nitrogen-rich syngas does not utilize a recycle loop and a recycle compressor.     

Possibilities and limitations of ecotoxicological testing of chemicals

This study concerns the polycyclic aromatic hydrocarbons (PAH's) emission from gasoline and diesel automobile engines.

The sampling procedure, the extraction and the analytical method are presented. Using the gas chromatography‐mass spectrometry technique it is possible to detect and quantify easily about 15 PAH's. Data obtained on exhaust particles collected from gasoline and diesel automobile engines are presented and discussed.     

Particulate and semivolatile associated aliphatic hydrocarbon exhaust emission from heavy duty diesel vehicles

The exhaust emissions from two heavy duty diesel vehicles running on eight different fuel compositions were investigated regarding their content of high molecular weight (≥ C₁₂) aliphatic/ olefinic hydrocarbons. It was concluded that the emitted amount of semi‐volatile associated aliphatic hydrocarbons (range C₁₂‐C₂₂) depend on the fuel used in the engines and that these emissions mainly consisted of uncombusted fuel components. It was also found that uncombusted engine lubrication oil was the main constituent of the emitted particulate associated aliphatic hydrocarbons (C₁₇‐C₄₀). These constituted between 58% and 95% of the total emissions of the high molecular weight aliphatic compounds. Emission factors for the total of high molecular aliphatic hydrocarbons (C₁₂‐C₄₀) were demonstrated to be in the range of 15–100 mg/km. Some individual aliphatic hydrocarbons with cocarcinogenic effects were identified and quantified in both particulate and semi‐volatile phases of the exhaust. Multivariate data analysis was used to investigate the relationship between fuel parameters and emission of semi‐volatile aliphatic emission.     

Environmental aspects of biofuels in road transportation

Energy is a vital and growing need for human activities such as transport, agriculture and industry. The transport and agriculture sectors are major consumers of fossil fuel. However, availability of fossil fuels is limited. The use of fossil fuels is of increasing environmental concerns because it produces toxic airborne particulates and greenhouse gases such as CO₂. The increasing industrialization and motorization of the world led to a steep rise for the demand of petroleum-based fuels. Hence, it is necessary to seek alternative fuels, which can be produced from resources available locally within the country such as alcohol, biodiesel and vegetable oils. Biodiesel is defined as the mono alkyl esters of vegetable oils or animal fats. Biodiesel is the best candidate for diesel fuels in the diesel engines. The advantage of biodiesel over gasoline and petroleum/diesel is its eco-friendly nature. This article reviews the production, characterization and current status of biofuels mainly biodiesel along with the environmental impacts of particulate matter, greenhouse gas emissions originated from biodiesel.     

Life cycle analysis and choice of natural gas-based automotive alternative fuels in Chongqing Municipality, China

Road transport produces significant amounts of emissions by using crude oil as the primary energy source. A reduction of emissions can be achieved by implementing alternative fuel chains. The objective of this study is to carry out an economic, environmental and energy (EEE) life cycle study on natural gas-based automotive fuels with conventional gasoline in an abundant region of China. A set of indices of four fuels/vehicle systems on the basis of life cycle are assessed in terms of impact of EEE, in which natural gas produces compressed natural gas (CNG), methanol, dimethylether (DME) and Fischer Tropsch diesel (FTD). The study included fuel production, vehicle production, vehicle operation, infrastructure and vehicle end of life as a system for each fuel/vehicle system. A generic gasoline fueled car is used as a baseline. Data have been reviewed and modified based on the best knowledge available to Chongqing local sources. Results indicated that when we could not change electric and hydrogen fuel cell vehicles into commercial vehicles on a large scale, direct use of CNG in a dedicated or bi-fuel vehicle is an economical choice for the region which is most energy efficient and more environmental friendly. The study can be used to support decisions on how natural gas resources can best be utilized as a fuel/energy resource for automobiles, and what issues need to be resolved in Chongqing. The models and approaches for this study can be applied to other regions of China as long as all the assumptions are well defined and modified to find a substitute automotive energy source and establish an energy policy in a specific region.