SETTLING SEPARATION OF CONTAMINANT IN WATER

摘要

PURPOSE:To obtain overflow water having high clarity by filtering off residual contaminant in the water while passing the water to be treated upward through a layer of powdery substance having small specific gravity before the water is overflowed. CONSTITUTION:A fine mesh metallic net 7 is provided between a peripheral wall plate 5 of a settling tank and a separating plate 6 of the setting tank, and a layer 8 of powdery substance having small specific gravity such as polystyrene, polyethylene, polyurethane, etc. is suspended below the net. When the treated water which has been freed of almost all contaminant by settling passes upward through the layer of the suspended small specific gravity substance, the incorporated residual contaminant is filtered off. Said small specified gravity substance is powder having 0.3mm. particle size and 0.2 specific gracity prepd. by expanding said resin, which forms a suspending layer having several tens - several hundreads mm. thickness when floating in the water below the net. If the particle size is made finer, filtered water having higher clarity can be obtd.