Determination of Residence Time Distribution (RTD), oxygen volumetric mass transfer coefficient (kLa) and mixing pattern in an Internal Loop Airlift Reactor (ILALR) for both living and nonliving systems have been investigated in this paper. Optimal operating condition is found at a gas flow rate of 2 l min−1. The estimated kLa values for nonliving and living system at 27°C are 0.004 s−1 and 0.017 s−1 respectively. Batch biodegradation of phenol with an initial concentration of 300 mg l−1 by the mixed microbial culture occurs at a very high degradation rate (0.16 mg l−1 h−1).
Keywords: ILALR, internal loop airlift reactors, volumetric mass transfer coefficient, RTD, residence time distribution, bubble diameter, phenol, Haldane substrate inhibition model, hydrodynamics, batch biodegradation