Simultaneous removal of ethyl acetate and ethanol in air streams using a gas-liquid-solid three-phase flow airlift loop bioreactor

A gas-liquid-solid three-phase flow airlift loop bioreactor was applied to treat air streams containing a mixture of ethyl acetate and ethanol. The activated sludge was replaced by biological membrane in the experiment. The influences of pH and jet waste gas influx on the removal efficiency and outlet ethyl acetate and ethanol mixture concentration were investigated. The optimum pH and jet waste gas influx were 6.0 and 4.4 m/s, respectively. Under the optimum operation conditions, the average removal efficiencies of ethyl acetate and ethanol in the mixture were higher than 98%. and accordingly, the outlet concentrations of ethyl acetate and ethanol were lower than 150 mg/m(3). The elimination capacities of ethyl acetate (504 g/m(3)/h) or ethanol (685 g/m(3)/h) in the mixture as two mixture pollutants, which were higher than those in biofilters (ethyl acetate 400 g/m(3)/h and ethanol 195 g/m(3)/h) reported in the literatures [Y.H. Liu, X. Quart, Y.M. Sun, J.W. Chen, D.M. Xue, J.S. Chung, Simultaneous removal of ethyl acetate and toluene in air stream using compost-bases biofilters, J. Hazard. Mater. B 95 (2002) 199-213; D. Arulneyam, T. Swaminathan, Biodegradation of ethanol vapour in a biofilter, Bioprocess Eng. 22 (2000) 63-67], were also higher than those of pure ethyl acetate (480g/m(3)/h) or ethanol (671 g/m(3)/h) as single pollutant in gas-liquid-solid three-phase flow airlift loop bioreactor. (C) 2004 Elsevier B.V. All rights reserved.