Emulsion liquid membrane for copper and cadmium removal

ELM is a multiple water-in-oil-in-water (W/O/W) emulsion system that consists of three main phases, membrane phase, internal phase and external phase. The aim of this research was to remove cadmium and copper using ELM and to identify the best physical condition to achieve maximum solute removal using ELM. Three parameters involved are pH of external phase, stirring speed and phase ratio as function of extraction time. To prepare membrane phase, surfactant (Span 80), carrier (D2EHPA) and diluents (kerosene) were mixed and HCl was added as internal phase at varying ratio from 1:1, 3:1, 5:1 and 10:1 of membrane phase to internal phase. The mixture was then homogenized by using ultra-speed homogenizer at various speeds starting from 5000 rpm to 15000 rpm. This mixture was then mixed by using agitator with different time at speed starting from 300 rpm to 700 rpm. Each sample was collected and analyzed using Atomic Absorption Spectrophotometer (AAS) to determine the copper and cadmium concentration. The percentage of copper and cadmium removal was calculated using the data obtained. The best pH was at 4 and 400 rpm was identify as the best stirring speed with 1/3 as the best phase ratio. It took 20 minutes for copper and 10 minutes for cadmium to achieve highest removal.