Cloud point extraction of La(III) by C13E10 non-ionic surfactant: Statistical refinement of experimental optimization by L9 Taguchi's design

The cloud point extraction experiments of La(III) ions using the C13E30 as non-ionic surfactant were carried out. The experimental optimization was realized by the classical method when optimizing one experimental factor at the time. The results showed that the La(III) ions were extracted at 61.77% and stripped from the loaded coacervate phase at 90.26% in one-stage with the nitric acid solution of 10(-1) M. The most influent experimental factors such as: initial concentration of feed phase (A), C13E30 concentration (B), quantity of sodium chloride salt (C) and pH of aqueous feed solution (D) were studied by the Taguchi's DOE methodology using an orthogonal array L-9 (34). Statistical study based on the ANOM and ANOVA analysis showed that the factor D constituted a noise and the levels optimum combination for the maximum extraction yield of La(III) was at: C-0 = 150 ppm and [C13E30] = 15% w/w without the add salt. These results were refined by using the Design-Expert 7 software where the predicted extraction yield of La(III) was in good agreement with that obtained experimentally (62.88% against of 61.77%), in which the standard deviation was of 1.81%. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.