Salt-tolerant Adsorbent For Expanded Bed Based On Cellulose/Stainless Steel Powder Composite Microspheres

Expanded bed adsorption (EBA) is a novel bioseparation technique, which integrates the clarification, concentration and initial purification into a single step operation unit. And that combine the ion exchange chromatography (EEC) with the hydrophobic interaction chromatography (HIC), a mixed-mode and salt-tolerant adsorbent was exploited and the protein binding capacity of the prepared adsorbent is independent on the salt concentration of the solution.In this work, a new type of composite matrix was prepared with cellulose as the framework , stainless steel powder as the inert weighted and the PEG as the porogenic agent through the water-in-oil suspension thermal regeneration method. Then, the physical properties and expansion characteristics of cellulose/stainless steel powder composite matrix were investigated systematically.The performance tests indicate that matrices have well macroporous structure, the protein binding capacity of the prepared anion adsorbent could increase 15 %; the expansion behavior of the matrices agreed well with the Richardson-Zaki law; the flow in expanded bed was proved to be plug flow for the composite matrices prepared.Finally, the paper studied on preparation of the salt-tolerant adsorbent. The optimized reaction conditions about upper ligand density were found to be as follows: the pH of reaction concentration at 10; the quality of benzoyl cysteine at 5g ; the reaction temperature at 50 °C and the reaction time at 12 h. The performance tests indicate that the protein binding capacity of the prepared adsorbent is independent on the salt concentration of the solution. The capacity of Lysozyme were 38 mg /mL and 28 mg /mL in packed bed and expanded bed. We could adopt pH change for protein desorption and the washing efficiency is 88% at pH11.