Removal of methanol vapors in a jet-loop bioscrubber equipped with a venturi injector

Abstract

A jet loop reactor equipped with a Venturi injector was used as a bioscrubber to treat air polluted with methanol. The oxygen transfer coefficient of the reactor was first characterized under abiotic conditions at different volumetric power inputs, ionic strengths and dynamic viscosities. The oxygen transfer coefficient (KLa) ranged 46.9–1272.82 h−1 with an actual volumetric power inputs from 3.6 to 21.5 kW m−3. Then, the reactor was inoculated with a mixed culture and applied for the treatment of air artificially polluted by methanol. Over 91 days, the actual volumetric power input was maintained at 11 kW m−3 and the KLa ranged from 720 to 860 h−1, while the volumetric loading rate was increased from of 5–60 g L−1 d−1 and the hydraulic residence time was increased from of 12–96 h. The volumetric methanol removal rate reached a maximum of 40.75 g L−1 d−1, at a removal efficiency of 67.6%. Under the optimal conditions tested, the microbial growth yield reached a minimum value of 0.11 g COD g−1 COD. These results suggest that high efficiency reactors such as the Venturi jet loop tested in the present work allow to reach high volumetric removal rates while maintaining low growth yield.