CLOURD-POINT EXTRACTION OF CHROMIUM(III) ION WITH 8-HYDROXYQUINOLINE DERIVATIVES

摘要

Cloud-point extraction, a less-common extraction metraction, a less-common extraction method, was used to extract chromium(III) ion from aqueous solution. Using a nonionic surfactant solution and 8-hydroxyquinoline (or a derivative), a chrominium(III) complex and unreacted chelating agent were extracted into the micellar phase at a temperature above the cloud-point temperature within two hours. The molar ratio, pH, temperature and hydrophobicity of the chelating agent were factors determining the extraction efficiency. Extraction efficiency was improved to 99/100, and chromium concentration was reduced from 55 ppm to less than 1 ppm when excess chelating agent was used at pH 5.5 at 70 deg C.