Separation of aniline from aqueous solutions using emulsion liquid membranes

An emulsion liquid membrane process is developed to separate aniline from d ilute aqueous solution. Aniline (amino-benzene) is a carcinogenic chemical common in industry and industrial wastewater. Due to aniline's high boiling point (183 degrees C) and low concentration in wastewater, more traditiona l methods of separation such as distillation are very energy intensive. Thi s emulsion process is offered as a low energy alternative, All separations occur in a Rushton stirred tank. The membrane phase consists of kerosene an d the surfactant sorbitan monooleate (span 80). Hydrogen chloride solution is the internal phase. This study also examines the effects of HCl concentr ation, aniline concentration, and the amount of emulsion on separation. Up to 99.5% of the aniline is removed from solutions containing 5000 ppm in as little as 4 min depending on process conditions. Leakage is minimal and sw elling is only about 3% after 5 min of processing. Approximately 98% of the membrane phase (both kerosene and span 80) is successfully recovered and r ecycled by using heat and/or adding 2-propanol fur demulsification. (C) 199 9 Elsevier Science B.V. All rights reserved.