Extraction of lead ions from aqueous solution by co-stabilization mechanisms of magnetic Fe2O3 particles and nonionic surfactants in emulsion liquid membrane

Abstract

A study of the impact of nonionic surfactants (span 80) on the emulsification of kerosene in the presence of magnetic α-Fe2O3 particles and the stability of the formed emulsions was carried out. Generally, emulsion liquid membrane (ELM) contains Bis-2-ethylhexyl phosphoric acid (D2EHPA) as a carrier, H2SO4 as an internal phase, kerosene as organic phase stabilized by an emulsifier, and co-emulsifier, which have been utilized to investigate its ability in the extraction of lead (Pb) from aqueous solutions. Further, the influence of experimental parameters affecting ELM stability and its extraction efficiencies such as emulsification time, homogenizer speed, surfactant concentration, Fe2O3-span 80 ratio, H2SO4 concentration, and the volume ratio of oil to internal phase (O/I), was examined. Additionally, investigation of the pH of feed solution, extractant concentration, agitating speed, the ratio of emulsion to the external phase (EM/E), initial lead (Pb) concentration, and contact time were carried out. The results confirmed the existence of co-stabilization strategy, which leads to the stability of the emulsion and improvement in the extraction efficiency of lead ions (Pb) to 97.2% after 8.0 min of mixing time under best-operating conditions with 0.3% membrane breakage.