The Separation and Concentration of Cr(VI) from Acidic Dilute Solution Using Hollow Fiber Renewal Liquid Membrane

Abstract

Hollow fiber renewal liquid membrane (HFRLM) technique for simultaneous separation and concentration of Cr(VI) from acidic dilute solution has been studied using tri- n -butyl phosphate as mobile carrier. The influences of the mobile carrier concentration, pH of the feed phase, the initial Cr(VI) concentration, and the stripping concentration on the mass transfer rate are investigated. The transport rate of Cr(VI) increases with increasing the carrier concentration and the stripping concentration, then reaches a “plateau”. The concentration factor as high as 25∼30 has been achieved easily. A mathematical model is proposed to explain the transport mechanism. The validity of this model is evaluated and good agreement between predicted results and experiment data are obtained. Results suggest that the HFRLM technique provides a promising alternative to treat industrial wastewater at low Cr(VI) concentration.