Development and application of the thin channel rectangular air lift mass transfer reactor to fermentation and waste‐water treatment systems

Abstract

SummaryThe consideration of fermentation principles in the treatment of industrial atid sanitary waste waters leads to substantial process improvements. In perticular, the rate of reaction can be improved by several fold by establishing the proper environmental conditions for microbial growth in a fermentation system. Recent work on the concentric cylinder air lift has shown it to be an economical fermentor with many advantages over conventional fermentors. An attempt to improve the economical performance of this system led to the development of the thin channel rectangular air lift fermentor. This was based upon a theoretical analgsis of performance parameters. The analysis indicates decreased bubble coalescence, increased bubble entrainment, decreased power costs, increased mass transfer coefficients, and decreased capital costs. Experience using a prototype thin channel rectangular air lift system with sanitary and industrial waste-water treatment systems has demonstrated exceptionally high rates of BOD removal at low operating and capital costs.

Gas holdup and overall volumetric oxygen transfer coefficient in airlift contactors

“…A dimensional analysis of the parameters that may affect (K,U,)~ in the airlift contactor was carried out. The effect of (UL)r on (K,a,), has been discussed earlier, and it is considered as an independent parameter in equation (14) because it has been shown to be variable with geometry or design of the AL contactor. Performing a dimensional analysis on equation (14) gives the dimensionless groups in equation (15).…”

Airlift Reactors: Characteristics, Applications and Design Considerations

“…The influence of induced liquid circulation on the riser gas holdup and on overall mass transfer were reflected in the correlations proposed by Bello el aL7' and Miyahara et aLs1 (Eqs. (29), (30), (41) in Table I). All these equations also contained gas velocity as a parameter but these two velocities were not independent of each other.…”

Kinetics and Transport Phenomena in Biological Reactor Design

“…A rectagular a i r l i f t has been repoted (Gasner, 1974) and airlifts with external recirculation (Kanazawa. 1975) have been proposed.…”