Emulsion liquid membrane for removal of pesticides from aqueous solution: emulsion stability and effect of operational parameters

The removal of lambda-cyhalothrin (LCT) from an aqueous solution was investigated and eval-uated by the emulsion liquid membrane (ELM) technique using Span 80 as the surfactant, n -hex-ane as the diluent, and HCl as the stripping phase. Crucial parameters influencing the stability of emulsions through breakage and extraction efficiency, such as emulsification time, surfactant con-centration, contact time, emulsification speed, internal phase concentration, external phase-to -mem-brane volume ratio, effect of feed pH, mixing speed, and internal phase-to-membrane volume ratio were investigated. The results indicated that 94.7% of LCT could be extracted at a contact time of 8 min under ideal experimental conditions, with a low membrane breakage of 0.48%. Furthermore, the extraction kinetics were investigated and the mass transfer coefficient was estimated. Based on the obtained results, the ELM technique could be a promising alternative method to minimize environmental pollution caused by pesticides to a large extent.