PURPOSE: To quicken the response to the quality change of treating water and to carry out sure waste water treatment, by adding sodium hypochlorite to the waste water containing ammonium compounds and after that, pH change of the waste water is measured and then, controlling subsequent adding quantity.
CONSTITUTION: pH of the waste water containing ammonium compounds sent in the reaction vessel 2 from the storage tank 1 is measured by the electrode 3. On the one hand, aqueous solution of sodium hypochlorite is supplied from the storage tank 8 to the vessel 2 and pH at that time is measured by the electrode 4. Information of said electrodes 3, 4 is inputted to the controller 5 and aqueous solution of sodium hypochlorite is added by controlling the pump 9 so that the value of the electrode 4 is higher than that of the electrode 3. After elapsed about one minute or more, pH of the treating water after decomposition reaction is measured by the electrode 6 and said value is inputted to the controller with the value of the electrode 3 and then, adding quantity of sodium hypochlorite is regulated by controlling the pump 9 so that the difference of both information substantially is zero. By this method, 100% removal of contained ammonia is made possible.
FUJITA KAZUNORI
KUBOTA SHIYOUJI
NAKASHIMA FUMITO
