PURPOSE: To provide a filter medium used for water treatment, which has high performance in capturing suspended matters long filtering life and small filtering resistance and is low in cost, by coating filtering sand with a cationic polymer.
CONSTITUTION: Sand gathered from the seaside or riverside is used as filtering sand, and the sand having about 0.1W5mm particle size is proper for said use. A polymer having a cationic particle charge, the cation structure of primary W quaternary ammonium ions in its molecule, and properties of well sticking to sand and of forming a film hardly soluble to water, is used as a cationic polymer. In a case of filtration, raw water is introduced from one side of a flow-in pipe 1 and is filtered by a upward flowing system by passing the raw water through a filter medium 6 supported by a wire net which is fixed with a flange 2 and a packing 3. The treated water flows out of over-flow pipes 7.
METSUGI MAKOTO
IMURA SENJI
MORISE YUKIO
KIKUI KAORU
KURIMOTO LTD
Next Patent: FILTER MEDIUM AND ITS MANUFACTURE