Electrofiltration of hydrophobic colloids in fluidized bed bipolar electrodes

• Main Author: Seoud, Hicham F.
• Format: Others
• Language: en
• Published: McGill University 1980
• Subjects: Colloids.; Electrodes.; Separation (Technology)
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=77086

A new process was developed for the filtration of hydrophobic colloids without the assistance of chemical coagulants. The process consists of passing the suspension through a bed of electrically conducting granules which are fluidized by the upward flow of the suspension and simultaneously exposed to a D.C. electric field. The process was demonstrated on an aqueous polystyrene latex of mean particle size 0.34 (mu)m. At optimum conditions a bed of iron granules retained 98% of the entering particles. === Experiments showed that the following variables increased the retention: increasing electric field strength, increasing static bed height, decreasing electrical conductivity of the feed, and decreasing the superficial velocity. Retention was independent of inlet particle concentration. === A model of the process was formulated including various mechanisms of deposition and surface forces. It contained no empirical factors from filtration experiments except the mean particle size in the effluent when electric field is applied. === Electrocoagulation of the polystyrene latex was observed under the microscope and the mechanisms involved were elucidated.