Criteria for Certification of Motor Vehicle Pollution Control Devices in California

This investigation used an acid medium for sampling atmospheric oxidants. The acid iodide oxidant procedure was unaffected by air or oxygen, temperature variance, and reducing gases (sulfur dioxide and hydrogen sulfide.) The method possessed good color stability. The method also agreed favorably with the 1 or 2% neutral buffered iodide method when a chromium trioxide scrubber was required to remove the reducing gases from the latter procedure.

The acid oxidant absorption solution of 1 3 ml in a midget impinger contained 10 ml of 1.5% potassium iodide in a 0.1 N sodium hydroxide solution and 3 ml of acetic acid (1:5) which produced a solution of approximately 3.8 pH. Particulate matter was removed by a glass wool attachment to the midget impinger. The air was sampled with a Gelman Sequential Sampler at the rate of 1.41 liters per minute. After the oxidant sample was collected, the absorbing solution was transferred to a graduated cylinder and the volume was adjusted to 25 ml with distilled water. The absorbance was read at 355 millimicrons wavelength by a spectrophotometer in a 1 cm cell. The acid oxidant method was effective between 1 to 70 pphm of ozone.     

机动车排放污染防治

介绍机动车尾气污染的现状和危害，分析国外实现排放控制所经历程，探讨我国控制尾气污染的措施和支撑技术。     

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.     

九江市机动车尾气污染控制对策

机动车尾气已成为城市重要的空气污染源之一,对城市的环境影响越来越严重.根据《九江市环境保护“十一五”规划》,九江市机动车尾气污染的控制势在必行.因此,为了有利于城市机动车尾气污染的综合整治和科学管理,结合该市特征和机动车尾气污染现状,在分析机动车尾气污染形成原因的基础上,提出了控制城市机动车尾气污染的对策.     

A Fuel-Based Motor Vehicle Emission Inventory

Abstract

A fuel-based methodology for calculating motor vehicle emission inventories is presented. In the fuel-based method, emission factors are normalized to fuel consumption and expressed as grams of pollutant emitted per gallon of gasoline burned. Fleet-average emission factors are calculated from the measured on-road emissions of a large, random sample of vehicles. Gasoline use is known at the state level from sales tax data, and may be disaggregated to individual air basins. A fuel-based motor vehicle CO inventory was calculated for the South Coast Air Basin in California for summer 1991. Emission factors were calculated from remote sensing measurements of more than 70,000 in-use vehicles. Stabilized exhaust emissions of CO were estimated to be 4400 tons/day for cars and 1500 tons/day for light-duty and medium- duty trucks, with an estimated uncertainty of ±20% for cars and ±30% for trucks. Total motor vehicle CO emissions, including incremental start emissions and emissions from heavy-duty vehicles were estimated to be 7900 tons/day. Fuelbased inventory estimates were greater than those of California's MVEI 7F model by factors of 2.2 for cars and 2.6 for trucks. A draft version of California's MVEI 7G model, which includes increased contributions from high-emitting vehicles and off-cycle emissions, predicted CO emissions which closely matched the fuel-based inventory. An analysis of CO mass emissions as a function of vehicle age revealed that cars and trucks which were ten or more years old were responsible for 58% of stabilized exhaust CO emissions from all cars and trucks.     

Pollution Control Progress

A scrubbing process for flue gas desulfurization, based upon naturally occurring carbonate rocks, has been developed from laboratory to pilot plant scale. Calcitic limestones are better sulfur dioxide absorbents than dolomitic ones when used in the slurry form. The process was tested on a 200-cfm pilot plant on a coal-fired boiler. Various types of scrubbing equipment were evaluated. Up to 80 per cent sulfur dioxide removal was feasible. The consumption of limestone ranged between 20 and 30 per cent more than the stoichiometric requirements.     

Effects of the Motor Vehicle Control Program On Hydrocarbon Concentrations in The Central Los Angeles Atmosphere

The body of information presented in this paper is directed to those individuals concerned with the effect of the motor vehicle control program on ambient hydrocarbon concentrations in a metropolitan area during peak traffic hours. The data used in this study are from gas chromatographic analyses of air samples taken in 1963-65, before implementation of the exhaust control program for new motor vehicles, and in 1971 and 1973, after several years’ application of this program. A brief history of the motor vehicle program in California together with emission standards for hydrocarbons are discussed and certain automobile-related hydrocarbons are identified and characterized. Frequency distributions were constructed for total hydrocarbons, non-methane hydrocarbons, methane, acetylene, and isopentane for 1963-65, 1971, and 1973 and the standard deviation (1 sigma) concentration limits are discussed for each of the subgroups mentioned above. The average concentration and relative percent comparisons for methane, ethane, n-butane, isopentane, C₃+ paraffin, eth-ene, propene, C₄ +olefin, acetylene, benzene, and toluene are shown and discussed in detail. These studies: 1) show hydrocarbon emissions from motor vehicles were reduced 47.6% during this time period; 2) indicate selective reduction of compounds; and 3) reveal a 51.8% reduction in the 1973 ambient total hydrocarbon concentration since 1963-65.     

Air Pollution Control Philosophies

Most air pollution control programs rest on one or more of the following four basic philosophies: emission standards, air quality standards, emission taxes, and cost benefit analysis. Frequently they rest on mixtures or combinations of these four. This paper examines each of the four separately, tries to show why each is different from the others, and compares their advantages and disadvantages.     

California Vehicle Exhaust Control

The purpose of this paper is to relate California’s experience with vehicle exhaust controls for three model years and to discuss future possibilities for improving the continued effectiveness of these controls. Tests of exhaust controls on 1966 and subsequent model cars in public use indicate a reduction in hydrocarbons of about 60% for the vehicle life of 100,000 miles compared to uncontrolled cars. However, emission levels and emission deterioration rates in public use are higher than those reported from proving ground tests. Significant percentages of new cars are delivered from the factory maladjusted which has a significant effect on emissions. These maladjustments are worsened by automotive service personnel.     

Careers in Air Pollution Control

Abstract

The destruction of parts per million (ppm) levels of volatile organic compounds in a dry air stream by high–energy electron–beam irradiation has been investigated in a pilot plant at the University of Tennessee Space Institute, Tullahoma, Tennessee. In a series of experiments, dry air contaminated with various VOCs in the concentration range of 50–1000 ppm were treated in the UTSI pilot plant to determine the extent of destruction at various electronbeam dose levels.

The destruction removal efficiency was determined as a function of the electron beam irradiation dose. The results suggest a charge transfer reaction as the major decomposition mechanism. A theoretical foundation of the process, along with a simple first–generation reaction kinetics model, a summary of the results from the pilot plant flow reactor, and a preliminary cost analysis for a fullscale detoxification plant using currently available electronbeam gun technology are presented in this paper.     

Designing for Air Pollution Control

This paper was one of several presented at the Workshop on Air Pollution Control in Portland, Oregon, on May 6, 1968. The Workshop was sponsored by the Manufacturing Chemists Association and the Chemical Industry Council of the Pacific Northwest in cooperation with the Association of Oregon Industries, Association of Washington Industries, and the Environmental Committee of the Portland Chamber of Commerce. While many of the papers were of localized interest, this paper speaks to anyone designing air pollution control systems.