汽车排气污染与治理的发展和动向

简介了汽车排气污染对人类健康和生态环境的影响；描述了世界汽车增长与排气污染的现状和发展趋势；综述了汽车排气催化净化技术所面临的挑战和最新研究动向。     

稀薄燃烧型汽车尾气净化的研究

随着我国汽车数量的增加，汽车尾气污染问题日益突出。稀薄燃烧型汽车以其节能性和低污染性得到了广泛的重视。本文主要阐述了稀薄燃烧型汽车尾气的净化研究，并提出了今后的发展方向。     

汽车排气催化净化用金属载体的生产工艺与设备

针对目前我国汽车排气净化催化剂用金属载体的生产现状和发展趋势进行了研究，简述了国内外汽车排气净化用金属载体的生产概况，对金属载体的工艺性能要求与陶瓷载体进行了比较；对金属载体的生产工艺与设备参数以及金属蜂窝载体的产品技术条件进行了分析和介绍。     

稀薄燃烧型汽车尾气净化的研究

随着我国汽车数量的增加 ,汽车尾气污染问题日益突出。稀薄燃烧型汽车以其节能性和低污染性得到了广泛的重视。本文主要阐述了稀薄燃烧型汽车尾气的净化研究 ,并提出了今后的发展方向     

汽车排气催化净化用金属载体的生产工艺与设备

针对目前我国汽车排气净化催化剂用金属载体的生产现状和发展趋势进行了研究 ,简述了国内外汽车排气净化用金属载体的生产概况 ,对金属载体的工艺性能要求与陶瓷载体进行了比较 ;对金属载体的生产工艺与设备参数以及金属蜂窝载体的产品技术条件进行了分析和介绍。     

昆山市区机动车排气污染负荷估算及污染控制对策

根据机动车构成,行驶工况和污染物排放系数,计算了１９９８年昆山市区机动车污染物排放量及机动车和固定源的排污分担率。结果表明,机动车已在为市区空气的主要排放源。结合国家技术政策和当地实际情况,提出了机动车排气污染控制对策。     

重庆市机动车尾气对大气环境的影响分析及减缓措施

在对重庆市机动车保有量、主城区交通状况进行深入调查的基础上，对机动车尾气排放对大气环境的影响进行了细致的分析与评估。阐述了机动车尾气是造成重庆市大气污染的重要因素。同时结合国内外一些先进的预防、控制和处理汽车尾气污染的方法，及近年来的观察、研究和试验，提出了合理减缓、控制机动车尾气污染的措施，以防止机动车尾气污染进一步蔓延。     

机动车污染排放模型研究综述

过去几十年,为了掌握机动车污染排放的规律和特征,向决策者提供科学有效的机动车污染控制措施,研究者们致力于研究机动车污染物排放的物化原理和影响机动车污染的主要因素,并据此建立多种尺度的机动车排放模型,以模拟城市区域或者街道的污染物排放.为了分析机动车的瞬态排放特征,目前的机动车排放模型研究正逐渐从宏观向微观发展,排放测试方法注重获取逐秒的排放数据,排放模型模拟的时间尺度和空间尺度逐步趋向微观.此外,机动车模型研究正趋向与交通模型进行耦合,从而揭示机动车在实际道路交通流中的排放特征.从机动车排放的主要影响因素、机动车排放测试、机动车排放因子模型及机动车排放清单等4个方面综述了国内外机动车排放研究现状和发展动向,对比并评价各种机动车排放模型方法的优缺点和适用范围,对我国的机动车排放模型发展方向进行了展望.     

实用高效的油烟净化技术及设备

随着餐饮业的快速发展，油烟的污染日益严重。探讨分析了目前油烟污染的净化处理现状，论述了新型高效的油烟净化技术机理，从而开发研制出经济实用的油烟净化设备，为我国控制油烟污染开辟了新途径。     

基于GIS城市机动车尾气扩散迁移研究

中国城市大气污染日趋严重，汽车尾气污染所占比重越来越大。交通、道路、管制及气候条件等是影响城市机动车尾气排放的主要因素。本文根据机动车尾气研究的实际，研究了专题MGIS数据库结构， 并以广州为例，建立了基于GIS的城市机动车尾气扩散迁移预报系统，在此基础上实现了机动车尾气污染状况的可视化。     

The impact of motor vehicle control technologies on future photochemical ozone formation in the United Kingdom

Legislation to control motor vehicle exhaust emissions has been introduced in the United Kingdom in stages since the early 1970s. Recently, a further step has been taken towards reducing future exhaust emissions of carbon monoxide, unburnt hydrocarbons and oxides of nitrogen in the 'Luxembourg agreement' (Lubinska, 1985). In this paper, the possible impact of these proposed controls on photochemical air pollution formation in the United Kingdom is investigated, including an evaluation of the relative merits of the two principal emission control options for petrol-driven cars: 'Lean Burn' engines and 'Catalyst' exhaust gas treatment.     

Measurements of ion concentration in gasoline and diesel engine exhaust

The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10⁶ cm⁻³ with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10⁸ cm⁻³ with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.     

激光质谱法对机动车尾气中污染物的测量

本文详细介绍了一种全新的污染物测试方法———激光质谱法的原理和特点。我们应用这一方法对机动车尾气进行了初步探测 ,得到了 2 6 6nm激光作用下汽车尾气的激光电离质谱图 ,并对摩托车发动机运行状态与苯系列污染物排放量之间的关系进行了初步的在线测量     

Status of Control of Motor Vehicle Emissions in California

The State of California, because of an acute air pollution problem has been forced to move ahead on a pioneer basis to control motor vehicle emissions. The Golden State’s program, as put into operation by the Motor Vehicle Pollution Control Board, is discussed in detail. Inspection-installation stations, enforcement and legal requirements relating to crankcase control devices and other facets of the program are presented. Of particular importance is the experience gained by the Board in requiring devices on all new vehicles registered in California and its used vehicle program, affecting vehicles back to the 1950 model year. Recent developments in exhaust control, anticipated installation requirements, and scheduling, as well as an indication of staff long-term planning is also outlined. California’s program is based on the principle that the motor vehicle must be controlled and that sewage no longer can be dumped into the air, if the public health is to be preserved.     

Research Note: Air pollution challenges and solutions for China's urban transportation development

China has experienced dramatic urbanisation and motorisation in the past 20 years. The phenomenal rise in the vehicle population in major cities has resulted in increased air pollution, traffic congestion and other 'wicked problems'. The Chinese government at all levels has made significant effort to control motor vehicle emissions, but vehicle population growth far outpaces their efforts, resulting in deteriorating air quality. Successful vehicle emissions control policies in industrialised countries offer China new technical and policy tools. This paper outlines China's current air pollution challenges and the technical and policy solutions under consideration by the Chinese central and municipal governments.     

Factors affecting heavy-duty diesel vehicle emissions

Societal and governmental pressures to reduce diesel exhaust emissions are reflected in the existing and projected future heavy-duty certification standards of these emissions. Various factors affect the amount of emissions produced by a heterogeneous charge diesel engine in any given situation, but these are poorly quantified in the existing literature. The parameters that most heavily affect the emissions from compression ignition engine-powered vehicles include vehicle class and weight, driving cycle, vehicle vocation, fuel type, engine exhaust aftertreatment, vehicle age, and the terrain traveled. In addition, engine control effects (such as injection timing strategies) on measured emissions can be significant. Knowing the effect of each aspect of engine and vehicle operation on the emissions from diesel engines is useful in determining methods for reducing these emissions and in assessing the need for improvement in inventory models. The effects of each of these aspects have been quantified in this paper to provide an estimate of the impact each one has on the emissions of diesel engines.     

Effects of water-emulsified fuel on a diesel engine generator’s thermal efficiency and exhaust

Water-emulsified diesel has proven itself as a technically sufficient improvement fuel to improve diesel engine fuel combustion emissions and engine performance. However, it has seldom been used in light-duty diesel engines. Therefore, this paper focuses on an investigation into the thermal efficiency and pollution emission analysis of a light-duty diesel engine generator fueled with different water content emulsified diesel fuels (WD, including WD-0, WD-5, WD-10, and WD-15). In this study, nitric oxide, carbon monoxide, hydrocarbons, and carbon dioxide were analyzed by a vehicle emission gas analyzer, and the particle size and number concentration were measured by an electrical low-pressure impactor. In addition, engine loading and fuel consumption were also measured to calculate the thermal efficiency. Measurement results suggested that water-emulsified diesel was useful to improve the thermal efficiency and the exhaust emission of a diesel engine. Obviously, the thermal efficiency was increased about 1.2 to 19.9%. In addition, water-emulsified diesel leads to a significant reduction of nitric oxide emission (less by about 18.3 to 45.4%). However, the particle number concentration emission might be increased if the loading of the generator becomes lower than or equal to 1800 W. In addition, exhaust particle size distributions were shifted toward larger particles at high loading. The consequence of this research proposed that the water-emulsified diesel was useful to improve the engine performance and some of exhaust emissions, especially the NO emission reduction.

Implications:The accumulated test results provide a good basis to resolve the corresponding pollutants emitted from a light-duty diesel engine generator. By measuring and analyzing transforms of exhaust pollutant from this engine generator, the effects of water-emulsified diesel fuel and loading on emission characteristics might be more clear. Understanding reduction of pollutant emissions during the use of water-emulsified diesel helps improve the effectiveness of the testing program. The analyzed consequences provide useful information to the government for setting policies to curb pollutant emissions from a light-duty diesel engine generator more effectively.     

Tomato Root: Site of Initial Alteration in Minor Elements in Cadmium Treated Plants

Abstract

Societal and governmental pressures to reduce diesel exhaust emissions are reflected in the existing and projected future heavy-duty certification standards of these emissions. Various factors affect the amount of emissions produced by a heterogeneous charge diesel engine in any given situation, but these are poorly quantified in the existing literature. The parameters that most heavily affect the emissions from compression ignition engine-powered vehicles include vehicle class and weight, driving cycle, vehicle vocation, fuel type, engine exhaust aftertreatment, vehicle age, and the terrain traveled. In addition, engine control effects (such as injection timing strategies) on measured emissions can be significant. Knowing the effect of each aspect of engine and vehicle operation on the emissions from diesel engines is useful in determining methods for reducing these emissions and in assessing the need for improvement in inventory models. The effects of each of these aspects have been quantified in this paper to provide an estimate of the impact each one has on the emissions of diesel engines.     

Exhaust temperature profiles for application of passive diesel particulate filters to solid waste collection vehicles in California

To reduce public exposure to diesel particulate matter (DPM), the California Air Resources Board has begun adoption of a series of rules to reduce these emissions from in-use heavy-duty vehicles. Passive diesel particulate filter (DPF) after-treatment technologies are a cost-effective method to reduce DPM emissions and have been used on a variety of vehicles worldwide. Two passive DPFs were interim-verified in California and approved federally for use in most 1994--2002 engine families for vehicles meeting min engine exhaust temperature requirements for successful filter regeneration. Some vehicles, however, may not be suited to passive DPFs because of lower engine exhaust temperatures. The purpose of this study was to determine the applicability of two types of passive DPFs to solid waste collection vehicles, the group of vehicles for which California recently mandated in-use DPM reductions. We selected 60 collection vehicles to represent the four main types of collection vehicle duty cycles--rolloffs, and front-end, rear, and side loaders--and collected second-by-second engine exhaust temperature readings for one week from each vehicle. As a group, the collection vehicles exhibited low engine exhaust temperatures, making the application of passive DPFs to these vehicles difficult. Only 35% of tested vehicles met the temperature requirements for one passive DPF, whereas 60% met the temperature requirements for the other. Engine exhaust temperatures varied by vehicle type. Side and front-end loaders met the engine exhaust temperature requirements in the greatest number of cases with approximately 50-90% achieving the required regeneration temperatures. Only 8-25% of the rear loader and roll-off collection vehicles met the engine exhaust temperature requirements. Solid waste collection vehicles represent a diverse fleet with a variety of duty cycles. Low engine exhaust temperatures will need to be addressed for successful use of passive DPFs in this application.