METHOD FOR REMOVING FLUORIDE FROM WASTE WATER CONTAINING FLUOROBORIC ACID

PURPOSE: A method for removing fluorine from wastewater containing fluoroboric acids is provided to remove fluorine in a fluoroboric acid form from wastewater although fluoroboric acids are hardly removed with a fluorine removal agent and a coagulant. CONSTITUTION: A method for removing fluorine from wastewater comprises the steps of: adjusting the pH value of wastewater containing fluoroboric acids to be in the range of 2-5; injecting a trivalent metal salt compound into the wastewater, and inducing the decomposition of the fluoroboric acids in the wastewater; injecting a divalent metal salt compound, which is combined with fluorine and forms a precipitate, into the wastewater, and adjusting the pH value of the wastewater to be in the range of 6.5-11; forming a precipitate of a compound based on the trivalent metal and fluorine and a precipitate of a compound based on the divalent metal and fluorine; and removing the precipitates from the wastewater. [Reference numerals] (AA) Raw wastewater; (BB) Boiler; (CC) Water collecting bath; (DD) First reactor; (EE) First settling bath; (FF,II) Supernatant; (GG) Second reactor; (HH) Second settling bath; (JJ) Effluent; (KK) Dehydrator; (LL) Waste treatment