Ultrafiltration concentrating of curd whey after electroflotation treatment

Abstract

This work offers a view on the outcomes of a study focusing on ultrafiltration of curd whey treated on the basis of the membrane electroflotation method in order to ensure more complete extraction of whey proteins when processing recoverable dairy crude. The feature that makes the method different is the presence of membranes between the anode and the cathode while the machines for membrane electroflotation are designed so that current does not run through the whey. To determine the element composition of whey prior to and after electroflotation the method of electron probe X-ray microanalysis was used. It has been shown that the filtration rate of whey treated through electroflotation nearly doubles up if compared to the initial rate. There has also been detected the dependence related to the impact that the concentration of solids and the pressure have on the filtration rate; besides, the kinetics of the ultrafiltration process has been investigated. The method of electron probe X-ray microanalysis was employed to study the element composition of whey both before and after the electroflotation treatment. The increase in the whey ultrafiltration rate after electroflotation can be explained by a growing Hydrogen index and a reduced concentration of Calcium after electroflotation. Besides, a quantitative physical model of whey ultrafiltration was developed, which takes into view specific features of polarization layer formation. The model implies conditional division of whey flow at the membrane surface into two streams - a normal one and a tangential one. Part of the protein molecules transported by the normal flow settles on the membrane surface while the other part of them remains near the surface up until it is pushed into the whey bulk by protein molecules of the tangential flow. That all mentioned above fixes certain elements of newness in the field of membrane technologies. The study was performed at the Voronezh State University of Engineering Technologies and the North Caucasus Federal University (Russian Federation)