METHOD AND APPARATUS FOR TREATING SELENIUM-CONTAINING SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a treating method for a selenium-containing solution which can reduce the amount of an added ferrous compound required for removing selenium in a solution like waste water generated after washing dust, and decrease the concentration of selenium in the treated solution to or below an effluent standard value (≤0.1 mg/l as a residual selenium concentration). SOLUTION: The treating method comprises (A) a process where an acid is added to selenium-containing waste water in a pretreatment tank 2 to adjust its pH to 4 or below and in such a condition, the ferrous compound like ferrous chloride is added thereto to obtain a solution containing divalent iron ions, (B) a process where an alkali agent 16 like calcium hydroxide is added at an alkali agent supply opening 15 while making the solution obtained in the process (A) flow into a passage 3 and the pH of the solution on the downstream side is adjusted to 8-12 to obtain a solution containing a solid comprising metal selenium and ferrous hydroxide, and (C) a process where the solution obtained in the process (B) is subjected to solid-liquid separation by using a filter 5. COPYRIGHT: (C)2005,JPO&NCIPI