ABSTRACT
Air pollution occurs when chemical, physical, or biological agents are injected into the atmosphere in concentrations high enough to damage property, ecological systems, and human health. The Clean Air Act of 1970 and amendments of 1977 form the basis of air pollution control policy. The purpose of the Clean Air Act is to protect and enhance the quality of US air resources. To protect air quality in clean air regions, the Environmental Protection Agency developed and Congress authorized regulations controlling the introduction of new sources of the criteria pollutants. The Clean Air Act requires uniform national emissions standards, based on technical and cost factors, for all new sources of air pollution. The emissions control options for gaseous pollutants are few and expensive. The three major options are afterburners for combustible gases, absorption, and adsorption. Absorption systems involve the pumping of gases through chemical or water sprays so that all the molecules of the gas come into contact with the liquid.
