Bioremediation of contaminated air using an external-loop airlift bioreactor

Biological air treatment methods are gaining popularity in the chemical industries due to their low cost and ability to convert many hazardous volatile organic compounds (VOCs) into harmless byproducts. An external loop, airlift bioreactor (ELAB) is used to separately bioremediate two prototype, water soluble VOC compounds: p-cresol and ethanol. In both cases, the effluent air was cleansed and bioremediated to below detectable limits (beyond 99.7% removal) due to the efficient scrubbing action of the ELAB. The bioreactor continued to provide this removal efficiency up to maximum air p-cresol concentration of 0.6 g/m(3) and ethanol concentration of 110 g/m(3) and at bioreactor loading rates up to 8 g/m(3) h for p-cresol and 220 g/m(3).h for ethanol. A dynamic and quasi-steady state, biokinetic model is shown to predict the transient bioremediation process very well using batch growth biokinetic parameters.