APPARATUS AND METHOD FOR TREATING SELENIUM-CONTAINING WATER

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for treating selenium-containing water, in each of which a high selenium removal rate is achieved by a small additional amount of ferrous salt and a generation amount of sludge is reduced.SOLUTION: The apparatus 1 for treating selenium-containing water, includes: an iron reaction tank 12 in which selenium in the selenium-containing water is reduced and agglomerated by the ferrous salt at the temperature of 50-95°C in a pH range of 7.0 or higher and lower than 8.0; a re-agglomeration tank 14 in which an alkali is added to the reduced water obtained in the iron reaction tank so that the pH of the alkali-added reduced water is made equal to 8.0 or higher and lower than 10.0 to re-agglomerate the selenium; and a precipitation tank 18 in which an agglomerated product is separated from the re-agglomerated water obtained in the re-agglomeration tank.