Mass Transfer Characteristics Of Hemoglobin Solution In Ultrafiltration Membrane Separation

With the fact of the world's wide blood resouce shortage ,blood substitute is an artificial product which can partly replace human blood in function. Hemogloblin is the main protein that enables red blood cell(RBC) to carry oxygen and transport it to many tissues and organs. Nowaday's research about blood substitute pays much attention to hemogloblin and its derivatives .Therefore it's very important that we should study on the theory of the purification of hemogloblin and the practice. As one of the membrane separation technologies, the pressure of ultrafiltration is about 0.01~0.5Mpa. It has the advantage of small working space, low energy cosumping, few request for pump and tubular products. And it also has the feature that its pressure is quite small and the equipment is simple. With these yeas'widely application of ultrafiltration in our country, membrane ultrafiltration has been used in biomedical and biochemistry at large, especially in protein separation and purification. In our research, we use ultrafiltration to purify hemogloblin from its suspension, and study the mass transfer features of the hemogloblin suspension in ultrafiltration. We also analyse the operating pressure's effects on membrane flux, and discuss the mechanism of the hemogloblin suspension's mass transfer in order to offer theory evidence for the production of this techonology.About our study:Objective:Optimize hemogloblin's ultrafiltration operating condition with the mass transfer model to separate hemoglobin with high purification, offer theory referrence for preparing hemogloblin using membrane.Methods: hemoglobin solutions were concentrated by membrane ultrafiltration, then analysed the ultrafiltration effect under different pressures and the relationship between pressure and flux. Finally, we discussed the mass transfer mechanism in the progress of ultrafiltration.Results:①For the solution concentration of 1.69,2.07,2.66,3.66 g/L, the ultrafiltration flux was 1.9275,1.8750,1.8125,1.7500 L/m2·h respectively at the pressure of 0.04 MPa, 12°C;②For the different pressure: 0.02,0.03,0.04,0.05,0.06 MPa , the ultrafiltration flux was 0.165,0.245,0.325,0.400,0.475 L/m2·h respectively with the same time;③The result is quite good, detected with the method, the concentration of the purified hemogloblin solution is improved 10 times than before, and is close to fitting experimental data.Conclusion: During the progress of ultrafiltration, the character of membrane flux can separate in stages: the value of membrane flux was higher at the beginning, and then became stable. As calculated from the equation about the flux, the membrane resistance was 0.1182, and the pressure coefficient was 0.128. However, the gel layer was gradually formatted with the higher Hb concentration; it's hard to concentrate the hemoglobin when the concentration was equal to the gel concentration. In our experiment, the gel concentration Cg was 18.82 g/L, and the ultrafiltration mass transfer coefficient was 0.7008.