OXIDATION OF ETHANOL VAPORS IN A SPIRAL BIOREACTOR

A fixed film spiral bioreactor containing immobilized activated sludge microorganisms has been used to degrade ethanof vapors. The effect of air flow rate, and ethanol feed concentration on elimination capacity has been investigated. Air flow rate is varied in the range from 2.34 to 40.0 dm(3) min(-1). Ethanol feed concentration is varied in the ra nge from 600 to 7000 ppmv. In the concentration range studied, the eli mination capacity increased proportionately with an increase in feed c oncentration. However, the elimination capacity decreased significantl y at flow rates greater than 20 dm(3) min(-1) owing to insufficient re sidence time. The maximum elimination capacity observed was 185 g etha nol h(-1) m(-3) of reactor volume. Critical ethanol loading, defined a s the maximum loading to achieve greater than 99% elimination at vario us residence times have been determined. These data are extremely usef ul in designing bioreactors for large scale applications.