Real‐time control of air pollution

Abstract

The problem of determining real-time (episode) air pollution control strategies for an urban airshed is posed as selecting those control measures from among all possible such that air quality is maintained at a certain level over a given time period and the total control imposed is minimum. The real-time control is based on meteorological predictions made over a several-hour to several-day period. A computational algorithm is developed for solving the class of control problems that result. The theory is applied to a hypothetical study of the effect of implementation of the optimal control on September 29, 1969, in the Los Angeles basin. CHWAN SCOPEOne of the important environmental problems facing urban officials today is the selection and enforcement of air pollutant emission control measures. These measures take two forms: long-term controls (multi-year legislation, such as the Federal new car emission standards through 1976) and short-term controls (action taken over a period of hours to days to avoid an air pollution episode). What is required for each form of control is a methodology for the systematic determination of the best strategy from among all those possible. The development of a theory for setting long-term controls is in progress Kyan, 1971, 1972;Trijonis, 1972). The objective of this paper is the presentation of a theory for the determination of short-term, or real-time, control for urban air pollution.The determination of real-time controls requires a number of elements: (1) a dynamic mathematical model of atmospheric pollutant concentrations, including meteorological variations and atmospheric chemistry, (2) a contaminant emissions inventory for the airshed, including the temporal and spatial variation of all primary pollutant emissions, (3) an enumeration of all feasible control strategies, and (4) some measure(s) of air quality. Given these elements, the problem is posed as choosing the set of control measures which just maintain air quality and do so at the minimum control level.Typical control measures include restrictions on the number of motor vehicles allowed on a freeway, reduced operation of power plants, and substitution of low emission fuel (for example, natural gas) for high emission fuel (for example, coal), in power plants. The control strategy is assumed to be enforced over a certain period, say, one hour, based on meteorological predictions made at the beginning of the period. The strategy for each time period could be determined by an air pollution control agency by means of a computer implementing the algorithm presented. CONCLUSIONS AND SIGNIFICANCEThis paper consists of three parts: (1) the formulation of a general real-time air pollution control problem, (2) the development of a computational algorithm for solving the class of control problems which result, and (3) an application of the theory to a hypothetical study of the effect of implementation of the opimal control on September 29, 1969, in the Los Angeles basin. It is assumed that a mathematical model of pollutant b...

H∞Control Theory Using in the Air Pollution Control System

“…We can make the quantity of pollutant discharged that meets a certain environmental goal to be permissible total emission. Only when the pollutant emissions beyond atmospheric self-purification ability, namely, exceeds the environmental capacity, there may be air pollution [8].…”