Research On Removal Of Organic Pollutants In Water By Emulsion Liquid Membrane And Heat-induced Demulsification Technology

As one kind of liquid membrane technology, emulsion liquid membrane (ELM)has the advantages of large contact area, high mass transfer rated. Especially, with theaddition of carrier, it can achieve selective transmission. Also, the solvent, surfactantand carrier can be recovered. Since it was invented, ELM had become the researchfocus. It has been applied in many fields involving wastewater treatment, foodindustry，pharmaceuticals and metallurgy.ELM can achieve high mass transfer properties, but it is difficulty to demulsifythe emulsion after treatment. It is a restriction for the solvent and surfactant recycle.The commonly used method for demulsification is costly and low efficient andhindering the industrial application of ELM.In this article, polyoxyethylene ether surfactant which is temperature-sensitive isused for ELM system. The effects of different variables on emulsion stability arestudied. Heat-induced demulsification efficiencies with variables involvingtemperature, surfactant concentration, internal reagent, volume ratio of internal phaseto oil phase are investigated.Based on the results mentioned above, experiments for removal of pyridine andphenol from wastewater by emulsion liquid membrane and heat-induceddemulsification are conducted. Effects of variables on removal efficiency arediscussed. The results show that in optimization condition, it can reach high removalefficiencies (96.5%for pyridine,95.7%for phenol). The emulsion used can be totallydemulsified around70to80℃. High removal efficiencies still can be achieved byusing the recycled solvent and surfactant. It confirms that the emulsion liquidmembrane and heat-induced demulsification system has high mass transfer efficiencyand the emulsion is recyclable, as a result, it has good industrial application value.