| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of treating wastewater containing organic substances by which excess sludge can be reduced while effectively utilizing almost all of an existing wastewater treating system. <P>SOLUTION: The method comprises a process (a) of decomposing the organic substances in the wastewater by microorganisms in a biological treatment vessel, a process (b) of separating part of activated sludge generated in the process (a) as excess sludge, a process (c) of sterilizing the the excess sludge, and a process (d) of returning the sterilized sludge to the biological treatment vessel. The process (c) comprises such steps that one or more metal couples wherein two kinds of metals are arranged facing each other are immersed into the excess sludge, that the two kinds of metals are electrically connected between them in the outside of the excess sludge, that metal ions are eluted into the the excess sludge by the difference of oxidation-reduction potential of the two kinds of metals, and that at least a part of the microorganisms in the excess sludge are sterilized by the metal ions. <P>COPYRIGHT: (C)2004,JPO</p> |
