Demineralization of animal blood plasma by ion exchange and ultrafiltration

The blood waste from slaughterhouses is strictly controlled due to its high pollutant load, the treatment for its purification being of great economic interest. The separation of proteins, the most valuable components of blood, in a chromatographic column requires the use of well treated plasma, in particular the removal of inorganic salts. Accordingly, a demineralization process is usually required. In this paper, ion exchange and ultrafiltration demineralization techniques were tested and the results compared. In the ion exchange experiments, the blood plasma was treated with cationic and anionic resins in packed columns, studying the removal of the major cations and anions, protein loss and pH evolution in both the loading and elution steps. In the demineralization process by means of membranes, a 10 KDa ultrafiltration membrane was used, the blood plasma being filtered to concentrate all the proteins in the retentate while removing the inorganic ions and other compounds in the permeate. The evolution of the major anions and cations in the plasma and the protein loss were studied at different volumetric concentration factors. The results obtained enable us to draw conclusions as regards the advantages and disadvantages of each technique at a laboratory scale and to offer some considerations regarding the operation at an industrial scale.