| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for making a cake having a low water content by treating a waste liquid containing a plurality of metals to make slurry containing iron whose filterability and drainability are improved, and dewatering the same. <P>SOLUTION: The method is characterized by supplying an acidic waste water containing a plurality of metal ions in addition to a divalent iron ion and a trivalent iron ion to a first reactor, oxidizing the divalent iron ion to the trivalent iron ion by biological oxidation means or chemical oxidation means, also adjusting the pH of the waste liquid at≥3 and≤5 by adding a neutralizer, preparing a particle composed mainly of iron hydroxide (III), supplying a part of slurry of the waste liquid containing the particle to a second reactor, adjusting the pH of the slurry in the second reactor at≥5 and≤13 by adding an alkali agent to return to the first reactor after each particle is flocculated, carrying out solid-liquid separation of the slurry containing the flocculated particle to concentrate, and thereafter dewatering the concentrated slurry to make a cake. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
