Enrichment Technique of Heavy Metal Ions in Water by Electromembrane Isolation

Rapid enrichment and purification method for low concentration metal ions in solution was proposed.The target metal ions formed coordinated complex with anion first.Under the positive voltage traction,metal complexing ions reached the surface of the ion-exchange membrane and passed through cation exchange membrane under the attraction of anionic membrane layer.It formed anionic complex again in receptor solution and moved to the anode zone in the electric field.Enrichment current found was 1.5 mA.Enrichment times of Hg2+,Cd2+ found were 20,60 min respectively.Enrichment facors of Hg2+,Cd2+ in water sample found were 10.5,3.2 times,respectively.This method avoided the defect of liquid membrane stability.