Impact of hydrodynamic regime on the capacity of oxygen transfer in a stirred electroflotation column

Abstract

Electroflotation (EF) is a relatively new technology for industrial wastewater treatment. It is considered as the electrochemical version of the traditional flotation. It is distinguished by the mechanism of bubbles production. In this context, we studied oxygen transfer in an agitated EF column by Rushton turbine (TR). The capacity of oxygen transfer is controlled by the volumetric mass transfer coefficient (K_La). This coefficient was experimentally evaluated for different hydrodynamic regimes. The hydrodynamic regimes are associated with the variation of Reynolds number relative to the agitation movement and to the movement of gas bubble in the liquid phase. Model of K_La was established in order to describe the effect of the operating parameters and the Reynolds number on the oxygen transfer rate. Such model allows the prediction of optimal treatment regime when EF is used as an industrial process to treat wastewaters.

Keywords:

• Electroflotation (EF)
• Coefficient of oxygen transfer
• Agitation
• Reynolds number