7 - Control Devices: Electrostatic Precipitation, Scrubbing, Mist Elimination, Adsorption, and Combustion of Toxic and Hazardous Wastes

Abstract

This chapter discusses the techniques of electrostatic precipitation, scrubbing, mist elimination, adsorption, and combustion of toxic and hazardous wastes. There has been a considerable quantity of research conducted in the area of electrostatic precipitation. The development of an optimized collection system for high-resistivity particulate matter includes an efficient pre-charging system coupled to a high electric field downstream collecting system. Thus, the optimization of both the pre-charger and collection systems can be approached independently. New approaches to energization have ranged from the use of computers to operate a more conventional type of transformer–rectifier (T–R) set to the use of pulse energization. These developments provide the user with a variety of energization options in the operation of the ESP system. Wet scrubbers are used to remove particles and gases from gas streams by contacting them with a liquid, usually in the form of droplets. Conventional wet scrubbers remove particles by using inertial and diffusional mechanisms. Mist eliminators are used to remove droplets of liquid from process and exhaust gas streams. Adsorption is used to remove organic and inorganic material from gas streams by contact with a solid. Combusion, in addition to its significance to power generation, is a viable treatment process for the ultimate disposal of a large variety of toxic and hazardous chemical wastes.