PURPOSE: To recover waste water as intermediate water to be used in toilet flushing and other purposes, by adding coagulant to waste water to float the suspended substance with air bubbles as scum, and floating fine suspended substance with bubbles of oxygen and hydrogen produced by hydrolysis, and adsorbing organic matter, etc. with active carbon.
CONSTITUTION: Coagulant 5 such as aluminum sulfate is added to waste water 10 to be treated to adjust pH to 6W8, and is introduced into a floatation band 1 in the treating tank from a lower part 12. At the same time, air is dissolved in an air dissolving tank 3, and the air pressurized in a compressor 4 is introduced. The supended substance in the waste water is changed to scum 9 by the coagulant, and floats up with air bubbles produced from the pressurized water, and is discharged as overflow. The discharge water goes down in an electrolytic band 2, and passes through granular active carbon 7 charged in a supporting electode 6. Fine suspended substance is floated and removed by the bubbles of oxygen and hydrogen generated from the surface of active carbon 7 polarized by inter-electrode voltage. The organic matter, nitrogen compound and metal ions in the waste water are adsorbed and removed by the active carbon, so that intermediate water to be used as toilet flushing water and air conditioning water may be recovered.
KUBOTA MASAYOSHI
KANEKO TOYOHIKO
TAKAHASHI SANKICHI
