Impact of anionic surfactants on oxygen transfer rate in the electroflotation process

Abstract

This work concerns the treatment of liquid effluents rich in anionic surfactant by the electroflotation process in batch mode. The oxygen transfer was studied considering its importance for the abatement of the dissolved organic matter in the industrial effluents. The volumetric mass transfer coefficient (K L a) which is the key parameter in the characterisation of transfer process was evaluated for different values of current density and various surfactant concentrations. The volumetric mass transfer coefficient was also dissociated to evaluate the liquid-side mass transfer coefficient (K L) and specific interfacial area (a). The K L decreases with the anionic surfactant concentration until the critical micelle concentration and then it has undergone a notable increase, the specific interfacial area decreases with the anionic surfactant. Models of (K L) have been established to describe the effects of the operational parameters as well as the physicochemical characteristics of the liquid phase on the oxygen transfer.

Ultrafine Kaolinite Removal in Recycled Water from the Overflow of Thickener Using Electroflotation: A Novel Application of Saline Water Splitting in Mineral Processing

“…Ti electrodes play a fundamental role in the removal of kaolinite. The generated bubbles and flocs are created according to electrochemical reactions shown in Equations ( 3)-( 6) [53][54][55][56][57]. The microbubbles of H2 and O2 generated on the surface of the Ti electrodes in contact with a saline electrolyte during the EF process proceed via specific mechanisms of H2 evolution reaction (HER) and O2 evolution reaction (OER) in Equations ( 3) and (5), For NaCl electrolytes, the high R MF values observed at runs with 20 V/SHE and 20 min indicates large amounts of Ti flocs that were efficiently removed.…”

Electroflotation Extraction of Lanthanum and Scandium Hydroxides From Aqueous Solutions

“…Special attention should be paid to the effect of organic surfactant additives and flocculants on electroflotation in aqueous solutions. Surfactants are often applied for optimization of the separation process; they affect the bubble size [27,28] and therefore the oxygen transfer rate. Moreover, surfactants can also be extracted from aqueous solutions using electroflotation [29].…”