AWWA JAW25635 ✓ Most Recent

Acid-base reactions occur simultaneously with gas transfer reactions in several common applications in water and wastewater treatment. A simple methodology to account quantitatively for the effects of the acid-base reactions on the gas transfer rate was developed, checked by comparison with laboratory data, and applied to an actual drinking water problem situation. Equations for application to a variety of gasliquid contacting reactors are given. The rate of gas adsorption or stripping was shown to be drastically influenced by pH in applicable cases. Laboratory results for stripping of carbon dioxide in batch reactors and continuous-flow countercurrent packed towers compared excellently with the theory. The theory was applied to a full-scale operating system in which hydrogen sulfide is stripped from a groundwater drinking water supply; simultaneous stripping of carbon dioxide and oxidation of the sulfide were accounted for. Reduction of the influent pH was recommended to improve the stripping of the hydrogen sulfide. Includes 18 references, figures. See more