Owing to the inherent inefficiency of dewatering equipment widely used today, the search for improved dewatering techniques has been pursued by the investigation of new innovative ideas. The main thrust of these investigations has been in electroosmotic dewatering which presents a novel approach in South Africa.

The separation of the sludge liquid phase is governed by the intensity of binding forces. There are different physical forms of water in sludge and these different forms play an important role in determining the ease or difficulty of phase separation. It seems that the inefficiency of dewatering applied to gelatinous and fine-particle sludges can be overcome by mechanical dewatering enhanced by electroosmosis. A prototype pilot-plant embodying these principles has been developed for commercial application to dewatering of troublesome sewage sludges.