Microscopic Study On Stability Of Emulsion Liquid Membrane And Extraction Efficiency Of Cr (Ⅵ) From Wastwater

Using a capillary video microscopy technique, the stability of TBP-Span80-kerosene emulsion liquid membrane (ELM) system was investigated by preparing a single W₁/O/W₂ double emulsion globule. The efficiency of ELM for removing Cr (â…¥) was also studied. Combining these two experiments, the effects of pH, Span80, TBP and NaOH on both the stability and Cr (â…¥) extraction efficiency were analyzed. It was found that the oil-soluble surfactant was the key factor for the ELM stability and the system stability was enhanced with increasing surfactant concentration. In order to remove Cr (â…¥) effectively with ELM, the surfactant concentration must be above the minimum concentration required for the stability of ELM. Acidity reduces the stability but it is required for the removing process, and it is favorable to the oil-water separation after the reaction. TBP has no remarkable impact on the stability, however, NaOH in the internal water phase has great effect on both stability and Cr (â…¥) extraction...