Abstract

Masoud Nasiri Zarandi and Amirhossein Soltani

DOI : http://dx.doi.org/10.13005/ojc/340609

The purpose of this study was to investigate the extraction of lead by emulsion liquid membrane as an effective alternative to conventional lead extraction methods. The emulsion included D-2-ethylhexyl phosphoric acid (D₂EHPA) as a carrier, paraffin and kerosene composition as an organic solvent, Span 80 as an emulsifier and sulfuric acid as an internal stripping phase. In this project, 7 effective factors in extraction of lead were chosen by emulsion liquid membrane, which included concentration of sulfuric acid in the internal phase, volume ratio of the emulsion to external phase (R_ew), the ratio of organic phase to internal phase (R_oi), initial pH of external phase, contact time of the emulsion and external phase, carrier concentration and concentration of surfactant in the membrane phase. After the initial experiments to make a stable emulsion, membrane phase mix (70% paraffin and 30% kerosene), homogenizer speed (12000 rpm) and mixer speed (309 rpm) were selected. The final experiments were designed by Taguchi statistical method. Optimization was done according to higher extraction rate and the effect of each of these factors and their optimal values as well as optimal conditions were determined. By verification test, it was shown that more than 92% of lead can be extracted from a solution with a concentration of 2000 ppm.

Emulsion Liquid Membrane; Extraction; Lead; Taguchi Analysis; Wastewater

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