Stability of emulsion liquid membrane using bifunctional diluent and blended nonionic surfactant for phenol removal

Abstract

This study investigates the interfacial stability of emulsion liquid membrane (ELM) for phenols removal through the introduction of blended surfactant in the formulation of liquid membranes. The stability was studied in terms of emulsion breakage time and droplets size distribution. The components used in ELM were a mixture of palm oil and kerosene (7:3) as a diluent, sorbitan monooleate (Span 80) and polyoxyethylene sorbitan monooleate (Tween 80) as a surfactants, and sodium hydroxide as a stripping agent. Parameters such as hydrophilic-lipophilic (HLB) value, mixed surfactant concentration, homogenizer speed, emulsification time and organic-to-internal (O/I) ratio were evaluated. Results show that stable emulsion was formed at HLB 5, 3 % (w / v) of blended surfactant, 8000 rpm of homogenizer speed, 3 min of emulsification time and 3:1 O/I ratio. 83.4 % of phenol were extracted under these conditions without any emulsion breakage or swelling. Thus, Span 80 and Tween 80 mixture has high potential as surfactant and is capable to increase the stability of emulsion.