New technique for kla measurement between gas and water in aerated solvent-in-water dispersions
ABSTRACT A new technique is presented to determine gas-to-water overall volumetric mass transfer coefficients (k
a) in a stirred-tank reactor containing solvent-in-water dispersions. The compound to be transferred from the gas to the water was toluene; the water-immiscible organic solvent was FC40, a perfluorocarbon. The k
a was determined in steady-state conditions in the absence of biological consumption. Toluene removal was achieved by passing a continuous flow of toluene-free water through the reactor. When solvent was present it was separated from the water at the reactor outlet by means of a small settler and recycled back to the vessel. The k
a was found to increase with the FC40 volume fraction. An enhancement of 1.9 times on an aqueous-phase-volume basis was found at 15 % (v/v) FC40.