Foam fractionation is an economical and effective technology for protein concentration and separation However the presence of antifoaming agent in the fermentation broth restricts the application of this technology In this paper surfactant-assisted foam process was conducted with a mimic system using bovine serum albumin (BSA) as target protein polyoxypropylene polyoxyethylene glylerin ether (PGE) as antifoaming agent and cetyltrimethyl ammonium bromide (CTAB) as surfactant putting emphasis on study of the effect of ionic strength on the separation process The experimental results showed that with ionic strength increasing the mixed-system foaming ability gradually increased Under the conditions of C-BSA 100 mg/L C-CTAB 20 mg/L C-PGE 8 mg/L and pH 74 feed liquid 250 mL air flow rate 100 mL/min at 25 C the maximum enrichment ratio of BSA reached 27 when the ionic strength was 0 0500 mol/kg and the maximum recovery of BSA reached 80 5% when the ionic strength was 0 1696 mol/kg Furthermore K+ had better separate efficiency than Na+ under the same ionic strength (C) 2010 Elsevier B V All rights reserved