Effect and optimization parameters of phenol removal in emulsion liquid membrane process via fractional-factorial design

Abstract

Phenol removal from wastewater was investigated and optimized using formulated blended surfactant ionic liquid emulsion liquid membrane. In this research, a mixture of kerosene and palm oil was chosen as a liquid membrane phase medium. The components utilized in the emulsion formulation are palm oil to kerosene (7:3 ratio) as diluent, blended surfactant of Span 80 and Tween 80 as surfactants, ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]+[NTf2]−) as a stabilizer, and sodium hydroxide (NaOH) as a stripping agent. The experimental of extraction process was designed and optimized using fractional-factorial design and response surface methodology (RSM) respectively. In this study, the optimum process conditions were obtained at an agitation speed of 267 rpm, 5 min of extraction time, 0.107% (w/v) of the concentration of ionic liquid and treat ratio of 1:7.3 where 83% of phenol was extracted in stable duration process without emulsion breakage. Meanwhile, about 11 times enrichment ratio of phenol was recovered as concentrated phenolate solution in the stripping phase. In conclusion, emulsion stability, phenol extraction and recovery could be increased using blended surfactant ionic liquid.