METHOD FOR REMOVING SELENIUM FROM CHLORINE BYPASS DUST FLUSHING WASTEWATER

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PROBLEM TO BE SOLVED : To remove selenium from wastewater generated when flushing a chlorine bypass dust at high efficiency while suppressing an operating cost low.SOLUTION : A method for removing selenium in which pH of wastewater generated when flushing a chlorine bypass dust is adjusted to be pH of 3.0 or more and less than 7.0 and the wastewater is brought into contact with adsorbent containing rare earth compounds. The rare earth compounds may include one kind or mixture of two kinds or more of the rare earth compounds selected from oxides or hydroxide of yttrium, lanthanum, cerium, ytterbium. It is preferable to use ones constituted by carrying the rare earth compounds on porous inorganic materials or organic materials as the adsorbent. Wastewater generated when flushing a chlorine bypass dust, wastewater obtained by adding NaSH solution, hydrochloric acid, hydrated lime to the wastewater sequentially, and wet exhaust gas desulfurization wastewater using calcium contained chlorine bypass dust recovered by a chlorine bypass system attached to cement producing facilities may be objects.