Experimental and modeling studies on Cd (II) ions extraction by emulsion liquid membrane using Triton X-100 as biodegradable surfactant

Abstract

In the recent years, the Emulsion Liquid Membrane (ELM) is considered as an attractive effective and alternative technique for the removal of toxic heavy metals from various aqueous waste effluent streams. In this work, ELM method is used to remove cadmium ions from stream water. Emulsion liquid membrane consisted of kerosene as organic solvents; Triton X-100as stabilized biodegradable surfactant and di-(2-ethylhexyl) phosphoric acid(D2EHPA) as carrier or extractant. At a fixed temperature (20 °C) Cd (II) extraction yield, Y (%), quantifying the efficiency of the process, was considered as a function of three parameters: D2EHPA/Triton X-100 ratio ranging from 0.5 to 3.5, initial feed phase concentration between 300 and 500 ppm and feed phase pH from 5 to 9.The experimental of the process parameters was optimized using an empirical smoothing method. The results were represented on three-dimensional plots using the Box-Behnken design and the response surface methodology. It was indicated that the calculated values being in good agreement with experimental data that under the optimized conditions ([Cd] =500 ppm, V agitation = 200–300 rpm, t = 20 min and pH = 7.6), Cd (II) ions extraction was recorded more than 98% of efficiency.