NON-WASTE WATER FLUE GAS TREATMENT SYSTEM AND NON-WASTE WATER FLUE GAS TREATMENT METHOD

The present invention is provided with: a desulfurization device 14 which removes sulfur oxides contained in boiler flue gas 12; a spray drying device 19 which sprays desulfurization waste water 15 discharged from the desulfurization device 14 and which dries the waste water by introducing a drying gas 12a; a flue gas supplying line L13 which returns, to a main flue L11, flue gas 12b obtained after the desulfurization waste water 15 is evaporated and dried; an alkaline agent supplying unit 22 which adds an alkaline agent 21 to a desulfurization waste water line L21 located between the desulfurization device 14 and the spray drying device 19; and a chlorine ion measurement device 26 which is provided in any one of or a plurality of the main flue L11, the flue gas supplying line L13 and the desulfurization waste water line L21, wherein the alkaline agent 21 is added in accordance with a result of the chlorine ion concentration measured by the chlorine ion measurement device 26 in any one of or a plurality of fluids of the main flue L11, the flue gas supplying line L13 and the desulfurization waste water line L21 to cause a molar ratio of alkaline agent 21 and chlorine ion to fall within a predetermined range.