Commercialization of Pressurized Electroosmotic Dehydrator (PED)
Application of electroosmosis to conventional filter press dehydrators has been studied to decrease water content in the sludge generated from waste water treatment process. Experiments realized the reduction of water content in the biological excess activated sludge down to 50-60%, which had never been achieved by the conventional dewatering method. The new method has been commercialized by pre-concentration of the excess activated sludge, addition of electrolyte, and development of special carbon electrodes. Moreover, observation using a scanning electron microscope enabled us to demonstrate the suitability of the PED process to the excess activated sludge. The newly-developed dehydrators and processes have been operating successfully at three commercial plants for the first time in the world.