ABSTRACT
Gaseous pollutants in air, such as carbon monoxide, the oxides of nitrogen, the oxides of sulfur, and unburned hydrocarbons, are by far the major pollutants in terms of mass. For outdoor air, approximately 90% by mass of the air pollutants are gases, with most being the result of combustion of fossil fuels and biomass. For many indoor environments, the ratio of gaseous pollutants to the total could be higher. Absolute concentrations of gaseous pollutants in indoor air, however, are relatively low. Four general categories of gaseous pollutant control technologies are commonly used to remove gaseous pollutants from air: adsorption, absorption, catalytic conversion, and source reduction. This chapter describes the principles of the first three categories.
