Separation and Determination of Cadmium(II) in Wastewater by Bisolvent of Ester and Ionic Liquid Flotation System

Abstract

In this study, the flotation technology was used to separate and enrich the heavy metal Cd 2+ ions. Based on literature, it was found that Cd 2+ could form CdI4 2-with KI in solution and then (RhB)2(CdI4) was occurred when CdI4 2-was mixed with rhodamine B. This ternary associate was determined by bisolvent of ester and ionic liquid flotation system. Ionic liquid was [Bmim]BF4, the optimal amount of acetic acid, potassium iodide and rhodamine B was 8, 20 and 4 mL, respectively. The best removal efficiency obtained at a flotation time of 15 min with air flow rate of 30 mL/min and 38 % mass fraction of (NH4)2SO4 solution was 95.68 %. The experimental data indicated that the ionic liquid have more excellent function than the traditional organic solvents.