PREPARATION OF FILTER MEDIUM FOR TREATMENT OF WASTE WATER CONTAINING FLUORINE

• Main Author: KAMIYOSHI HIDEKI
• Format: Patent
• Language: English
• Published: 24.08.1984
• Subjects: CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PURPOSE:To prepare a filter medium capable of effectively removing F from waste water contg. F by molding a mixture of an insoluble Ca salt with a powdery magnetic body and treating the molded product with pressurized steam. CONSTITUTION:Powdery magnetic body of such as Fe3O4 or magnetite is mixed in 30-60% with powder of an insoluble Ca salt such as CaCO3, Ca(OH)2, CaSO4, CaF2, CaSiF6. A solidification accelerating agent such as water glass, and water, and the mixture is kneaded. The kneaded product is solidified in an autoclave by treating it with pressurized hot water. The product is prepared to 30-150 mesh grain size to obtain a filter medium 6, which is packed in a column 3. The water to be treated 1 having a pH adjusted to 8.0 is admixed with a CaCl2 soln. to obtain a mixture having Ca/F molar ratio of 5, and the mixture is fed from the bottom of the column 3. In this treatment, a magnet 4 is disposed to the top of the column to form a thin fixed layer of the filter medium 6 and to form a fluidized layer 6b below the fixed layer. F in the water to be treated is adsorbed by the filter medium 6 and removed, and the treated water is discharged through the filter 5.