VOLUMETRIC OXYGEN MASS-TRANSFER COEFFICIENT IN AN UPFLOW COCURRENT PACKED-BED BIOREACTOR

A new approach for volumetric oxygen mass transfer determination in an upflow cocurrent bioreactor packed with expanded clay balls is propos ed in this paper. The chemical method of CuCl oxidation was adapted fo r k(L)a determination in the Biological Filtration Oxygenated Reactor (BIOFOR(R)). The variations of water and air superficial velocities sh owed that the water superficial velocity significantly influences the oxygen mass transfer. However, variation of air superficial velocity h as little effect on the mass transfer coefficient. A mathematical proc edure is developed for k(L)a calculation using experimental results. T o predict the volumetric oxygen mass transfer coefficient, a modified correlation, published by Reiss (1967, I&EC. Proc. Des. Dev. 6, 486-49 9), is proposed. Using water superficial velocities and pressure drop, this correlation enables the determination of the k(L)a coefficient a t any time, during the biological wastewater treatment cycle. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.