Selection of design parameters and optimization of operating parameters of soybean oil-based bulk liquid membrane for Cu(II) removal and recovery from aqueous solutions

The objectives of this work were to select suitable design parameters and optimize the operating parameters of a soybean oil-based bulk liquid membrane (BLM) for Cu(II) removal and recovery from aqueous solutions. The soybean oil-based BLM consists of an aqueous feed phase (Cu(II) source), an organic membrane phase (soybean oil (diluent), di-2-ethylhexylphosphoric acid (D2EHPA) (carrier) and tributylphosphate (phase modifier)) and an aqueous stripping phase (sulfuric acid solution (H 2SO 4)). Effects of design parameters (stirring condition and stripping/membrane to feed/membrane interface area ratio) of soybean oil-based BLM on the Cu(II) removal and recovery from aqueous solutions were investigated and the suitable parameters were selected for further studies. Optimization of the operating parameters (D2EHPA concentration, H 2SO 4 concentration, stirring speed, temperature and operating time) of soybean oil-based BLM for maximum percentage (%) recovery of Cu(II) was then conducted using Response Surface Methodology and the optimum parameters were determined. A regression model for % recovery was developed and its adequacy was evaluated. The experimental % recovery obtained under the optimum operating conditions was compared with the predicted one and they were found to agree satisfactorily with each other.