The effect of metal ions on humic acid removal and permeation properties in an ultrafiltration system.

With a view to improving the removal of humic acid from aqueous solution, the effect of metal ion addition on the separation of humic acid from water in an utrafiltration (UF) system was investigated. The valence of the metal ion and the molar ratio of humic acid to metal ion strongly affected the permeation flux during ultrafiltration. It was found that the ionic strength, dissociation constant and operating pressure were not major factors affecting the separation performance of the ultrafiltration process.