A method of removing contaminants from a gas stream utilizing a supersonic venturi including a converging section, a throat, and a diverging section is provided. A contaminated gas stream and a scrubbing liquid stream are introduced into the converging section, thereby forming a mixed stream which experiences choked flow upon exiting. The choked mixed stream is introduced into the throat section wherein the scrubbing liquid is contacted with the contaminated gas stream. The contaminated scrubbing liquid stream is removed from the supersonic venture scrubber, and an essentially pure gas stream is removed from the diverging section. A flow modification device may be introduced into the throat section. The flow modification device may be either axially or radially adjustable in order to effect the atomization of the scrubbing liquid and/or the contacting of atomized scrubbing liquid with the contaminated gas stream within the throat section.