Optimization of Bioscrubber Performances: Experimental and Modeling Approaches

Abstract

The deodorization efficiency of a suspended-growth bioscrubber was characterized from an experimental and theoretical approach, in order to optimize such systems for the treatment of polluted air from wastewater low lift station. A model of prediction of volatile compound removal efficiencies was developed according to operating conditions and contact mode (packed and spray column). The predictive ability of the model was validated from transfer data obtained with two representative molecules (ethanol and hydrogen sulfide) on a laboratory scale device. The theory takes into account the hydrodynamic characteristics of the fluids flowing in the contactor, which were defined from a previous experimental residence time distribution study. A study of parametric sensitivity of the model was then conducted to evaluate the influence of operating conditions (gas and liquid flow rates, contact mode, washing solution characteristics), hydrodynamic parameters of each flow (liquid holdup in the column, hydrodynamic behavior of the liquid flow, axial dispersion of the gas flow), and biodegradation step on the deodorization efficiency of a bioscrubber applied to the treatment of a polluted gas containing ethanol. The assumptions of sizing and optimization were confirmed on a suspended-growth bioscrubber used for the deodorization of an exhaust gas emitted by a wastewater low lift station.