| 摘要 |
PROBLEM TO BE SOLVED: To provide a heavy metal-containing water treating system with simple and practically superior steps, and effectively removing even heavy metals forming a firm complex from drainage. SOLUTION: The treating method includes steps of: adding a reducing iron compound to heavy metal-containing water; forming precipitation by leading the heavy metal-containing water added with the reducing iron compound to a reaction vessel; separating the formed precipitation (sludge) into solid matter and liquid; and returning all or part of the separated sludge to the reaction vessel by turning it to alkalinity. The returned sludge is adjusted to pH of 11-13, the reaction vessel is adjusted to pH of 8.5 or more, and the reducing iron compound precipitation having green rust and iron ferrite as a main component is made to take in heavy metals in a sealed non-oxidation environment for precipitation. The treating method has a step of decomposing the heavy metal complex by adding hydrogen peroxide to the heavy metal-containing water and by Fenton oxidation in the presence of a ferrous compound, prior to the adding step of the iron compound. COPYRIGHT: (C)2009,JPO&INPIT
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