Although Venturi scrubbers are used predominantly for control of particulate air pollutants, these devices can simultaneously function as absorbers. Consequently, absorption devices used to remove gaseous contaminants are referred to as absorbers or wet scrubbers (USEPA-84/03, p. 1-7). To remove a gaseous pollutant by absorption, the exhaust stream must be passed through (brought into contact with) a liquid. The process involves three steps: