To provide a water purification method and apparatus which perform compaction of precipitate and are excellent in solid-liquid separation properties and in economy and treatment effect since ferrite treatment can be carried out at room temperature.
The water purification method comprises a pretreatment process for precipitating pollutants by ferrous hydroxide, and a post-treatment process for further precipitating the pollutants by a sediment-like clarification material (a GR clarification material) consisting of a mixture of green rust and ferrite. In the water purification method and apparatus, desirably, precipitation is carried out under a nonoxidizing atmosphere after introducing raw water into a pretreatment tank, treated water from which precipitate has been separated is introduced into a reaction tank in the post-treatment process, precipitation is further carried out under a nonoxidizing atmosphere and an alkaline condition, the whole or a part of the separated precipitate is introduced into a regulating tank and then an alkali is added thereto, and the precipitate regulated by the alkali is returned to the pretreatment tank and the reaction tank in the post-treatment process to be used repeatedly.
HAYASHI HIROSHI
NAKAIE SHINTARO
