The Use of Aircraft in Air Pollution Research

An instrumented single engine aircraft is being used to characterize plumes from large emission sources. By cross sectioning these plumes at a number of points we hope to describe the character and concentration of pollution as it ages and travels downwind under known meteorological conditions. This paper reports experimental work thus far completed on aerosol measurement. Flights have been made through plumes from a large coal-fired power station, forest fires, and a gravel plant. Particle counts in various size classifications were made with a Bausch and Lomb 40–1 Dust Counter which was carried in the aircraft. Selected meteorological parameters were recorded. Results show the aerosol concentrations in various size classifications that are found at successive distances downwind from these sources for distances up to 32 miles. Background aerosol concentrations are also reported, and variations in these can be noted with respect to time, location and altitude.     

Air Pollution Research Problems

The TR-l Research Committee of the Air Pollution Control Association conducted a survey during 1969–70 to determine what air pollution research problems require attention. All APCA committees were requested to contribute topics to this survey, especially within their area of activity. Other professional societies were contacted through liaison representatives of APCA. The responses to the survey have been reviewed, categorized, selected, and edited for inclusion in this report. Additional material and concepts have been contributed by members of the TR-l Committee.     

The Opportunities for the Industrial Scientist-Engineer in Air Pollution Research

The industrial scientist-engineer is characterized by a high level of interest in solving problems, with the honest expectation that a novel solution to a problem will be rewarded by society with attendant economic benefits to his employer and to himself. Markets for new and improved emission control equipment and techniques are being created by the ever increasing public awareness of the consequences of continuing air pollution and suggest that new emission-free processes and manufacturing techniques and products will similarly find ready acceptance if not outright demand.     

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.     

Lidar Applications in Air Pollution Research and Control

The fundamental capabilities and limitations of the lidar (laser radar) in observing particulate concentrations in the atmosphere are discussed. The advantages of the lidar technique stem from its ability to obtain measurements remotely and at a high density in space and time. The quantitative application of the technique is limited by the accuracies with which: (1) the separate effects upon the return signal of back-scatter and attenuation may be identified; and (2) the optical parameters may be related to the characteristics of the aerosol. The main areas of utility for lidar in air pollution research and control are: (1) to observe the structure and height of mixing layers; (2) to measure the transport and diffusion of plumes or clouds of particulates; and (3) to remotely determine smoke-plume opacity. These applications are briefly reviewed and exemplified.     

Government Sponsored Air Pollution Research Relating to Agriculture

The absorption of hydrogen sulfide and methyl mercaptan by aqueous solutions of chlorine, sodium hydroxide, and chlorine plus sodium hydroxide was studied using a two-inch diameter absorption column packed with ¼ inch Intalox saddles. Absorption rates were noticeably affected by chemical reactions occurring in the aqueous chlorine and hydroxide media. These solutions were studied as a means of controlling sulfur-containing gas emissions from kraft paper mills. The absorption studies indicated that aqueous chlorine solutions at a pH above 12 were effective absorbents for hydrogen sulfide removal in absorption equipment designed to tolerate sulfur in suspension. The absorption of methyl mercaptan in aqueous chlorine solutions appeared to be impractical since dimethyl disulfide was apparently the only product formed and was stripped from the tower by the gas stream. Sodium hydroxide solution was an effective absorbent for both methyl mercaptan and hydrogen sulfide when hydroxide to sulfide or mercaptan feed ratios were greater than 1 or 1.8, respectively. The mercaptan absorption coefficient was approximately twice that for sulfide absorption.     

The Impact of Computers Upon Air Pollution Research

The electronic computer has had a profound effect upon air pollution research activities. This paper discusses some of the ways in which Public Health Service scientists routinely make use of the computer. It is used as a data processor to handle the large volumes of data resulting from continuous air monitoring devices. More importantly, it is used to perform the very complex computations involved in various statistical analyses and mathematical model building. In future years computers may be used on a real-time basis to control the sources which emit pollutants to the atmosphere.     

Air Pollution Equipment for Foundry Cupolas

The choice of air pollution equipment best suited for a specific foundry cupola involves the consideration of a number of factors.—They are: (1) The design of the cupola, including openings, door enclosures, height of stack, etc. These features greatly affect the size, cost, and efficiency of control systems. (2) The constituents of the effluent gas and the other properties, such as temperature and volume, are extremely important because corrosion, warpage, and low efficiency can result from these variables. (3) Four distinctly different types of air pollution control equipment are available for cupolas. They vary widely in initial cost, operating cost, and maintenance, but also vary widely in efficiency. (4) Local air pollution regulations and community considerations dictate the choice of air pollution equipment. Those regulations now in force are quite stringent in some localities, but quite lenient in others. An incremental approach to installation of systems would make one economically feasible for the small foundry.     

Annotated Bibliography for Air Pollution Meteorology

This annotated bibliography was prepared for the purpose of directing interested persons to some of the more helpful references in the field of air pollution meteorology. It obviously is not a complete listing. The reader who requires more information is directed to the references in the articles listed.     

Industrial Planning for Air Pollution Control

Seven general planning concepts for air pollution control are presented for industry’s consideration in this text of a speech delivered at the Air Pollution Control Workshop, New England Conference on Urban Planning for Environmental Health, Tufts University, Medford, Massachusetts, September 9, 1965.     

Air Pollution Acronyms

Abstract

Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion chamber of a solid waste incinerator provides crucial insight into the incinerator’s performance. However, the interrelation of the gas flow with the burning waste has not been adequately treated in many CFD models. A strategy for a combined simulation of the waste combustion and the gas flow in the furnace is introduced here. When coupled with CFD, a model of the waste combustion in the bed provides the inlet conditions for the gas flow field and receives the radiative heat flux onto the bed from the furnace wall and gaseous species. An unsteady one-dimensional bed model was used for the test simulation, in which the moving bed was treated as a packed bed of homogeneous fuel particles. The simulation results show the physical processes of the waste combustion and its interaction with the gas flow for various operational parameters.     

Air Pollution Control Costs for Coal-to-Electricity Systems

This paper describes a comprehensive set of economic models developed to assess the air pollution control costs of alternative systems for generating electricity from coal. Models of individual system components were formulated based on engineering and statistical analyses of other detailed models and data reported in the literature for currently available technologies. The air pollution control options modeled include 4 levels of physical coal cleaning, 3 types of dry fly ash collectors, a wet limestone FGD system, and 2 options for solid waste disposal. In addition, the cost of a power plant with no air pollution controls was modeled to determine the total system cost, including energy needed to operate environmental control systems. The principal criteria guiding the development of these models were that they be (1) computationally simple and economical to use, with a minimum of detailed data requirements, (2) sensitive to variations in pollutant emission regulations, coal characteristics, and key plant design parameters, and (3) systematic, based on a specified amount of power production and the same constant dollars. Extensive sensitivity analyses and case studies performed with these models indicate excellent agreement with the results of other studies and models applicable only to individual environmental control options. Applications of these models are discussed and illustrative results presented.     

Use of Plants for Air Pollution Monitoring

Leaf injury data from acute and chronic exposure studies of Dare soybean were regressed against the logarithms of exposure time and O₃ and SO₂ concentrations to develop a new two-pollutant leaf injury model (which explains 88% of the variance) and to calculate the parameters of best fit for this new model and a previously developed one-pollutant model. Using the calculated parameters, the percentage of leaf surface Injured over a growing season by O₃, SO₂, or both simultaneously was estimated for an ambient air sampling site located 2 miles from a coal burning power plant. For this site, the one- and two-pollutant models predicted that SO₂ effects would be negligible If SO₂ concentrations never exceeded the National Ambient Air Quality Standard (NAAQS) of 0.50 ppm, averaged over 3 h. However, calculations suggest that O₃ may injure up to 24% of Dare soybean leaf surface over a growing season even though the O₃ NAAQS of 0.12 ppm, averaged over 1 h, is never exceeded. Because the 3 h SO₂ standard is exceeded at very few places, the O₃ model is usually sufficient to estimate Dare soybean leaf Injury. Leaf injury is estimated by taking the logarithm of the summation of each daytime hour’s exponentiated O₃ concentration (c) measured at an ambient air sampling site over a growing season. This is expressed as: z = -0.0828 + 0.4876 in (Σco₃ ^2.618), where z is the Gaussian transform of percent leaf injury. The methods developed in this paper, using Dare soybean data as an example, may apply to other plants.     

Odor Determination Techniques for Air Pollution Control

Abstract

An airborne lidar was used to study the smoke plume from the burning of a controlled oil spill on the ocean. The ratio of the amount of light (at a wavelength, λ, of 0.532 u.m) backscattered by the smoke to the amount of light extinguished by the smoke was determined by measuring the strength of a laser beam after it had passed through the smoke plume, been reflected from the ocean, and passed through the smoke plume again, and comparing this to the strength of the laser beam reflected directly from the ocean. The optical depth of the smoke (at λ = 0.532 µm) was typically between 0.2 and 0.5. The mass fluxes of smoke particles that passed through four vertical cross sections of the (nonsteady state) smoke plume were estimated from lidar measurements to be 142, 175, 423, and 414 g ^s-1, compared to an average smoke mass production rate of ~770 g s^-1. The spatial distribution of smoke mass along the long axis of the plume was also estimated from the lidar measurements; derived smoke mass concentrations were generally <300 µg ^m-3, with a few isolated values up to ~800 µg ^m-3.     

Graduate Education for Air Pollution Control Personnel

Tendergreen bean plants were grown from seeding to seed maturity under continuous exposure to HF gas at fairly uniform concentrations averaging 0.58, 2.1, 9.1, and 10.5 µg F/m³. Progeny of these plants and of comparable control plants were grown in a clean atmosphere to determine if subsequent generations were affected by HF treatment of the parents.

No effects of HF were found among the progeny of the plants grown at 0.58 µg F/m³. The F₁ generation progeny of the other HF treated plants were less vigorous than control plant progeny, as shown by later emergence, smaller primary leaves, and slower stem growth. This probably was a consequence of the lower starch content of the seed of the HF treated plants. The primary leaves of some F₁ progeny of the plants grown in the three highest HF treatments were severely stunted and distorted. This also may have been due to the low starch content of the seed, or perhaps it resulted from damage to the plumules in shriveled, distorted seed produced in these treatments.

Some of the early trifoliate leaves of many F₁ generation progeny of the plants grown at 2.1 µg F/m³ and higher were abnormal in the separation and number of their leaflets. This abnormality apparently was heritable, for in the next (F₂) generation it occurred most frequently among plants whose parents were abnormal. However, considerably fewer F₃ generation plants had abnormal trifoliate leaves, indicating rapid reversal to the normal form.