Aluminum removal in clean water sludge and recovery manner

摘要

PURPOSE: To effectively utilize sludge in water purification as soil for growing crops and to enable the recycling of recovered aluminum as a flocculating agent by washing the sludge with hydrochloric acid or dilute hydrochloric acid, thereby recovering the soluble aluminum in the sludge. ;CONSTITUTION: The water from rivers is sterilized in a sterilizing tank 1 and is then introduced to a stirring basin 2 where polyaluminum chloride for waterworks is added as a flocculating agent to the water and the water is stirred. The flocs are sent to a floc forming basin 3 where the flocs are formed. The water contg. the flocs is sent to a settling basin 4 where the water is held still. Consequently, the sludge in water purification is formed. This sludge is sent into a sludge thickening tank 5 and is thickened. The sludge is further sent to a dehydrating machine 6. The dilute hydrochloric acid for neutralization is added to the dehydrating machine 6, by which the sludge is washed with the dilute hydrochloric acid simultaneously with the dehydration of the sludge. As a result, the soluble aluminum in the sludge is removed and the recovered aluminum is treated with a treating device 7 and is recovered.;COPYRIGHT: (C)1993,JPO&Japio