| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for clarifying raw water containing iron, manganese and ammoniacal nitrogen such as ground water, in which by oxidizing and filtering dissolved iron and manganese by a filter medium having attached microorganisms without using chemicals, the iron and manganese are removed while slightly leaving a part thereof and the ammoniacal nitrogen valuable as a fertilizer is left in treated water to obtain agricultural water allowing the saving of the fertilizer for an agricultural land. <P>SOLUTION: In the clarifying method, the iron removal and manganese removal of the raw water containing at least iron, manganese and ammoniacal nitrogen are performed by a biological filtering method. In the clarifying method, oxygen is dissolved in the raw water so that the dissolved oxygen concentration of the obtained treated water is 4 mg/L or more, iron removal, manganese removal and nitrification are controlled so that at least the ammoniacal nitrogen remains in the treated water and then filtration is performed by contact with microorganisms, thereby the treated water containing the ammoniacal nitrogen is obtained. <P>COPYRIGHT: (C)2013,JPO&INPIT |
