METHOD FOR REMOVING BORON IN WASTEWATER HAVING HIGH CONCENTRATION OF SALTS

摘要

PROBLEM TO BE SOLVED: To provide a method for effectively removing boron in wastewater having a high salt concentration or in wastewater having a high salt concentration and containing organic matter and carbonate. SOLUTION: A solution of magnesium chloride or magnesium sulfate is added to wastewater having a high salt concentration as magnesium ions and the pH of this wastewater is adjusted to 10.7-11.2 by a sodium hydroxide solution to form an insoluble substance of boron and magnesium by a co- precipitation method and this insoluble substance is separated to remove boron. Wastewater having a high salt concentration and containing organic matter and carbonate is held to pH 2 or less to be aerated or degassed under vacuum for 30 min and iron chloride is added to the wastewater as a divalent iron ion solution and magnesium chloride or magnesium sulfate is added thereto as magnesium ions and the pH of the wastewater is adjusted to 10.7-11.2 by a sodium hydroxide solution to form an insoluble substance of boron, magnesium and iron by a coprecipitation method and this insoluble substance is separated to remove boron.