The invention discloses a method for treating
vanadium industrial
wastewater by the aid of semi-dry
flue gas desulfurization ash. The method includes steps of (1), adding the semi-dry
flue gas desulfurization ash into the
vanadium industrial
wastewater; (2), adding inorganic acid into the
vanadium industrial
wastewater to regulate a pH (potential of
hydrogen) value of the vanadium industrial wastewater and stirring the inorganic acid and the vanadium industrial wastewater to obtain mixtures; (3), allowing the mixtures to stand still, separating supernatant from precipitates, carrying out pressure
filtration on the precipitates to obtain
calcium sulfate and mixing filter liquid and the supernatant with each other to obtain first mixed liquid; (4), adding
sodium hydroxide into the first mixed liquid, stirring the first mixed liquid and the
sodium hydroxide to obtain second mixed liquid, adding flocculating agents into the second mixed liquid and continuing to stir the flocculating agents and the second mixed liquid to obtain third mixed liquid; (5), allowing the third mixed liquid to stand still, separating supernatant from precipitates, carrying out pressure
filtration on the precipitates to form
chromium-containing green mud and mixing filter liquid and the supernatant with each other to obtain fourth mixed liquid; (6), leading the fourth mixed liquid into an
ammonia nitrogen precipitating tank, stirring the fourth mixed liquid, adding
magnesium salt and
phosphate into the fourth mixed liquid to obtain fifth mixed liquid, regulating a pH value of the fifth mixed liquid and then continuing to stir the fifth mixed liquid; (7), allowing the fifth mixed liquid to stand still and separating supernatant from precipitates. The method has the advantages that semi-dry desulfurization
solid waste can be recycled, accordingly, the wastewater treatment cost can be reduced, the problems of secondary
pollution and
land occupation of semi-dry desulfurization ash can be solved, and the method has high environmental benefits,
economic benefits and
social benefits.