Soybean Oil-Based Bulk Liquid Membrane for Simultaneous Extraction and Stripping of Cu(II) from Aqueous Solutions

Abstract

This work aimed to investigate the simultaneous extraction and stripping of Cu(II) from aqueous solutions through a soybean oil-based bulk liquid membrane (BLM). The membrane phase used was soybean oil (diluent) loaded with di-2-ethylhexylphosphoric acid (carrier) and tributylphosphate (phase modifier), whereas the stripping phase was sulphuric acid (H2SO4) at various concentrations. Effects of stirring condition, strip to feed interface area (S:F) ratio, H2SO4 concentration and operating time on Cu(II) extraction and stripping through soybean oil-based BLM were investigated. It was found that stirring affected the extraction process significantly but showed relatively smaller effect on the stripping process. The other parameters such as S:F ratio, H2SO4 concentration and operating time, however, were found to control the stripping process more than the extraction process. The highest extraction (98%) and stripping (86%) were achieved by using soybean oil-based BLM with four stirrings for all phases, S:F ratio of 2.5:1 and 3 M H2SO4 as the stripping phase within 24 h of operating time. Application of soybean oil-based BLM in real industrial wastewater was also investigated.