Pennsylvania’s Compuiterized Air Monitoring System

The Pennsylvania Air Pollution Commission has developed a regulatory program based upon the control of local air pollution problems and reduction of pollutant levels in air basins. The geographical boundaries of 10 air basins have been established. The Commission’s air basin regulations will provide for the reduction of over-all pollutant levels and for emergency procedures in the event of adverse meteorological conditions. The paper discusses the format and objectives of the program.

In order to effectively enforce the air basin regulations and maintain the necessary surveillance of the state’s air quality, a "computerized real time on-line integrated air monitoring-data handling system" has been designed. The system will incorporate a network to constantly monitor the air in each air basin.The primary objectives of the system are: 1. Constant surveillance of air pollution in the air basins.

2. Provide information on air pollution potential alerts.

3. Aid in further development of air quality criteria and regulations.

The air monitoring network is estimated to include approximately 25 remote stations. Each remote will contain air pollution and meteorological sampling equipment and hardware to telemeter to a central station. The data will be transmitted over leased telephone lines. The central station in Harrisburg will contain the necessary hardware to receive and process data, calculate and display results and permit supervisory control of the network. Output options will include immediate display of edited data, command and alarm information, and presentation of statistical results.

Although the air monitoring system is one of the principle ingredients of the program, the air basin concept encompasses other component systems designed to knit together the entire air pollution control program in Pennsylvania.     

enforcement of diesel smoke emissions for the state of new jersey

This paper reports on the research program undertaken by the State of New Jersey to determine those tests and instruments which can be used by authorized state agencies for the enforcement of diesel smoke emissions. The state agencies under consideration for the enforcement of diesel smoke emissions are the following: (1) The Division of Motor Vehicles, in its system of state owned inspection stations, will be able to inspect all diesel-powered trucks, and tractors which are registered in New Jersey. (2) The Public Utilities Commission will be able to inspect at their home garages all buses registered in the State. (3) The New Jersey State Police will be able to inspect diesel-powered vehicles on the road. It was decided that the maximum inspection time for each vehicle was not to exceed one minute. On the basis of the one minute per vehicle requirement, eight different tests were evaluated to determine which ones correlated well with normal vehicle operation. These tests included acceleration of a fixed external inertia, free acceleration of only the moving parts of the engine, three ramp tests, a test in which a heavy vehicle was towed, and a driving test in which the vehicle being tested was actually accelerated. The results of tests demonstrated that the modified free acceleration method correlates reasonably well with a loaded steady state cycle, distinguishes the high emitters and is simple to perform. Consequently, the free acceleration test method is recommended for use in inspection stations and on the road. Finally, nearly two hundred vehicles have been tested by this procedure to determine present and potential levels of diesel smoke emissions. Another phase of the program consisted of the determination of smoke measuring techniques and instrumentation. The use and design of smokemeters were extensively investigated, as well as the use of the visual and photographic techniques. Of the various smokemeters tested for this application, several measured smoke satisfactorily in the laboratory, but none were found adequate for field use; they either lacked portability or were unstable due to the deposition of soot on the optics. At the time of writing, specifications for the necessary smokemeter have been drafted and published for bid to interested manufacturers.     

The Number-Size Distribution of Atmospheric Particles During Temperature Inversions

Instruments capable of measuring in situ numbers of particles within specific size ranges covering a particle-diameter spectrum of approximately 0.001 – 10 microns have been employed to continuously monitor the concentration and size-distribution of atmospheric aerosols. The monitoring site was a television tower located on the boundary between Minneapolis and St. Paul, Minnesota. Air samples were drawn from 70, 170, and 500 feet above ground level and analyzed with optical, electrical, and condensation particle counters to obtain a number-size distribution within the 0.001 – 10 micron size range. In addition to the measurement of particle number and size, several micrometeorological parameters were simultaneously monitored. Particle number-size distributions which were measured during periods of temperature inversion are reported     

Product Guide/1970

Abstract

In Mexico City, the use and composition of fuels determine that carbon monoxide (CO) comes mostly from mobile sources, and sulfur dioxide (SO₂) from fixed and mobile sources. By simultaneously measuring hydrocarbons (HC), CO, and SO₂ in the atmosphere of Mexico City, the relative amounts coming from different sources can be estimated. Assuming that some HC are emitted proportionally to CO emissions, we can establish that [HC]₁= m1? [CO], where the proportionality constant ml corresponds to the ratio of emissions factor for HC and CO in mobile sources. Similarly for fuels containing sulfur, it can be assumed that [HC]₂ = m2 ? [SO₂]. In this way, the total HC are [HC]_total=[HC]₀+ ml ? [CO]+ m2 ? [SO₂], where [HC]₀ corresponds mainly to other sources like solvent evaporation, gas consumption, and natural emissions. In this way, it can be estimated that in Mexico City 75% of average HC comes from mobile sources, 5% from sulfur-related sources, and 19% from natural sources and solvent evaporation. Compared with the HC/CO ratio measured in the exhaust pipe of vehicles, we estimated that 70% of HC emitted from mobile sources are evaporative losses, and only 30% come through the exhaust system.     

The Removal of Particulate Matter from Fluid Bed Catalytic Cracking Unit Stack Gases

The application of a high-efficiency centrifugal type of separator to fluid bed catalytic cracking units is described in which most of the catalyst particles often lost to the atmosphere are concentrated into a small part of the stack gas (2%). A further separation can then be made on this small stream by an auxiliary separator which further concentrates the catalyst particle into 0.1% of the initia stream. Performance of the main and auxiliary separators are such as to reduce the loss of catalyst particles in the stack gas from 800 ppm to less than 60 ppm in a typical unit. Large amounts of power can be recovered by application of expander turbines to catalytic cracking plants employing this system of separation.     

On the Relation Between the Indoor and Outdoor Concentrations of Nitrogen Oxides

Simultaneous measurements were made of the concentrations of NO, NO₂, and CO inside and outside of a building. The building is located in the Los Angeles area, which is heavily polluted by photochemical smog, and the experiments were conducted at a time of the year when the pollutants in question tend to be high. The results shows that there is a direct relationship between the inside and outside concentrations, and that the phase lag between the concentrations depends principally on the ratio of the building volume to the ventilation rate. Although the outside concentrations of the pollutants in question did not follow the same pattern every day, peak concentrations seemed to be related to “rush-hour” traffic. By reducing ventilation rates during these periods, it may be possible to reduce the concentration peaks inside of the building. The building involved in the current study was not located in the immediate vicinity of heavy traffic, and the indoor concentrations of NO, NO₂, and CO did not appear to be very severe when compared to those defined by present air quality standards. Finally, the results support the belief that NO and O₃ do not co-exist indoors except in very small quantities.     

A Rating of the Major Air Pollutants and Their Sources by Effect

The available national annual air pollution emissions are based on mass. Different air pollutants have greatly different toxicities per unit mass, hence the emissions should be rated by effect, not by mass, so that more sensible priorities can be set in control research and regulation. Effect factors are derived from the health effect literature indirectly by using the national ambient air quality standards. The resulting analysis by effects shows transportation to be still the largest source as it is in the mass analysis while hydrocarbons become the largest pollutants by effect compared to carbon monoxide being the largest pollutant by mass.     

National Air Quality Standards for Automotive Pollutants – A Critical Review

The recently promulgated national air quality standards for carbon monoxide, nitrogen dioxide, hydrocarbons, and photochemical oxidant are critically reviewed.This review indicates that the standards are more restrictive than can be supported by available data.     

A Portable,Battery-Operated,Immediate-Readout Dust-Particle Analyzer

A portable, battery-operated, electro-optical dust analyzer operating on the principle of light scattering from individual dust particles in air drawn through a high-intensity light field has been developed for monitoring dust levels where external power may be unavailable. The instrument counts and size-discriminates airborne particles over two size ranges upwards of 0.3 microns with immediate readout. A dilution mechanism permits analysis of particulate concentrations as high as 2400 particles/cm³ on each channel. The self-contained Ni-Cd batteries are rechargeable. Total weight, including batteries and all components, is approximately 14 Ib. Total power used, mainly for pumping a filtered air sheath at 300 cm/sec and for the light source, is less than 34 watts. Another unique feature is the flow system designed for turbulence suppression.

Electronic calibration in terms of number of particles/cm³ for each size range is accomplished in the laboratory by means of a pulse generator with respect to which the readout indicator is calibrated for count. The input voltages to the pulse-height discriminators are appropriately attenuated for various pulse amplitudes simulating the output of the light-sensitive pickup, a photomultiplier tube.Pulse height as a function of particle size was measured for polystyrene latex beads ranging from 0.3 to 2 microns in diameter. Good correlation is obtained with results from commercial analyzers.

Field surveys have been undertaken with the CAES prototype analyzer at various sites in central Pennsylvania and at numerous sampling points within the cities of Pittsburgh and Philadelphia. Particulate concentrations as high as 1400 particles/ cm³ have been measured at a coal cleaning plant.