Electrophoretic pulse filter cake release in dead-end filtration processes

• Main Author: Ahmad, A. L.
• Published: Swansea University 1995
• Subjects: 620.106
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635852

The application of pulsed electric field for filter cake release is used in dead-end filtration processes to remove materials deposited on the membrane surface by means of an electrophoretic effect. The released materials are swept out of the filtration module immediately at the end of each cleaning interval. An automatic test rig was developed to carry out the experiments and the process was tested for microfiltration and ultrafiltration processes using inorganic and biological materials as the process feeds. The effect of the process variables of pulse interval, pulse duration, pH, ionic strength, feed concentration and voltage applied were studied in detail. The experimental data collected, for all parameters, show that the use of pulsed electric fields and filter cake release is an effective means of collecting filter cakes from the membrane surface at enhanced filtration rates. A force balance model was developed to predict the average filtration rate at the end of cleaning process, taking both electrophoretic and electroosmosis effects into account. This model shows reasonable quantitative agreement with the experimental values in many cases. The process developed is most likely to find application in the clarification of process streams of low solute content.