An Electro-Ultrafiltration/Electrodialysis Coupling Process for Concentration and Desalination of Protein Solutions

An electro-ultrafiltration/electrodialysis coupling process (EUF-ED) was proposed and performed for concentration and desalination of bovine serum albumin (BSA) solutions using a home-made EUF-ED membrane module, wherein an anion and a cation exchange membrane were designed at the anode and cathode sides, respectively. This process was compared with EUF and UF processes under the same operating conditions. The effects of electric current strength, feed concentration and flow rate, ionic strength of feed solution, electrolyte concentration and flow rate on the performance of the EUF-ED process were also investigated. Experimental results showed that the EUF-ED process could lessen concentration polarization and membrane fouling significantly, and enhance the permeate flux and decrease the salt content in BSA solutions simultaneously. The batch concentration experimental results showed that, as compared with the EUF, the EUF-ED process could reduce concentration time required by 20% and solution conductivity by 22% when a 150 mA electric current was applied. These results indicated that EUF-ED process could achieve higher efficiency at the same energy consumption and would be a promising method to promote the performance of electric field enhanced membrane process.