Microfiltration and ultrafiltration of milk: Some aspects of fouling and cleaning

Milk filtration using membranes is one of the most effective ways of separating fat, proteins and many types of microbial cells without the use of heat. This investigation was undertaken to determine the main factors responsible for the decline in permeate flux during milk processing and to study the fouling phenomena. There are a variety of fouling mechanisms, which may or may not bie significant depending upon the combined characteristics of the membrane, feed stream and operating conditions. In this study, the performance of a microfiltration membrane was compared with an ultrafiltration membrane in terms of fouling and cleaning characteristics using a cross flow membrane rig. Atomic Force Microscopy was employed to explore the fouling phenomena. Factors of importance for membrane cleaning such as temperature, transmembrane pressure, circulation time and cleaning performance were also investigated.