Removal of phenol from aqueous medium using micellar solubilization followed by ionic flocculation

Abstract

The disposal of phenol-bearing wastewaters impacts the environment and, consequently, the health of living bodies. This work evaluates the viability of using micellar solubilization followed by ionic flocculation in the removal of phenol from aqueous solutions. Initially, an anionic surfactant, based on vegetable oil and animal fat, was used to promote the solubilization of phenol in the micelles. Then, calcium was added to the solution to promote the formation of flocs with the ability to capture the phenol-rich micelles. At the end of the experiment, the authors investigated the influence of phenol removal considering surfactant, phenol, and electrolytes concentrations; calcium/surfactant ratio; temperature; pH; equilibrium time; and stirring speed. Phenol desorption from the floc surface was evaluated considering process efficiency and kinetics. The removal efficiency reached values close to 60% using: [Phenol] = 100 ppm, [surfactant] = 1300 ppm, 0.5 calcium/surfactant ratio, T = 35 °C, pH = 9.7. A 90% desorption was observed, indicating that desorption of phenol from the floc surface occurs spontaneously. Phenol desorption kinetics was fitted using the Lagergren's pseudo-first order model (R2 = 0.98).