Silver extraction using emulsion liquid membrane system containing D2EHPA-TBP as synergistic carrier: optimization through response surface methodology

Application of Response Surface Methodology (RSM) for the Optimization of Chromium(III) Synergistic Extraction by Supported Liquid Membrane

“…The experiments also were verified using statistical analysis, and a modified quadratic model was proposed according to the results. The regression reduced model equation for percentage Cr(III) extraction was expressed as Equation (5).…”

“…Addition of extractant/carrier mixture in appropriate proportion into the membrane phase has a synergistic and positive effect on improving both the rate and selectivity of the separation process. However, our previous works [1,4] and experiences of authors [5,8] show that the introduction of a second carrier into the liquid membrane causes an increase in the number of variable process parameters that have a decisive impact on the efficiency of the process. It is necessary to select the most favorable proportions of both carriers and determine their correlations with the most important process parameters such as the initial concentration of transported ions, duration of the process, and membrane stability.…”

“…The most popular types of ion metal carriers are crown ethers; organophosphorus compounds; and primary, secondary, tertiary, and quaternary ammonium salts [3]. However, in recent years, liquid membrane systems with a mixture of two extractants have become very significant in the separation of the metal ions [4][5][6][7][8]. Addition of extractant/carrier mixture in appropriate proportion into the membrane phase has a synergistic and positive effect on improving both the rate and selectivity of the separation process.…”

“…In recent years, the results of research on the optimization of the membrane separation process using RSM have been published increasingly more often [5][6][7][13][14][15][16]. Therefore, it also seems promising to improve the extraction of chromium(III) by the RSM in the supported liquid membrane system.…”

“…In the next step, the modelling of the process was achieved by response surface methodology (RSM) using Box-Behnken design (BBD). BBD was used because, as reported by other authors [5,12], it is a method created for estimating a quadratic model and requires only three levels for each factor and specific positioning of design points, providing strong coefficient estimates near the center of the design space. This means it is significantly easier than other DoE methods, as less time is required, and no runs are include factors outside the min/max values of the studied area.…”