METHOD AND SYSTEM FOR DECARBONIZATION, DECOLORIZATION, AND DECYANATION IN DEEP TREATMENT OF COKING WASTEWATER

摘要

A method and a system for decarbonization, decolorization, and decyanation in deep treatment of coking wastewater. The method comprises the following steps: 1) introducing coking wastewater into a Fenton fluidized bed, and adding a mixed solution of ferrous sulfate, sulfuric acid, and water to the solution; 2) adding hydrogen peroxide to the solution in the Fenton fluidized bed and reacting sufficiently; 3) extracting the reaction solution in the Fenton fluidized bed, adjusting the pH of the reaction solution, and adding a flocculant and obtaining a supernatant after precipitation; 4) mixing the supernatant with sodium hypochlorite and performing an oxidation reaction; and 5) adjusting the pH of the reaction solution, and using activated carbon to perform adsorption treatment, so as to obtain deep-treated water. The reaction in the Fenton fluidized bed, the flocculation and precipitation, the sodium hypochlorite oxidation, and the activated carbon filtration and adsorption are effectively combined. After flowing through the Fenton fluidized bed and the flocculation and precipitation, the effluent water contains residual cyanides present mainly in the form of CN^-, thereby allowing more efficient oxidization by sodium hypochlorite, and the cyanides can be removed by only first-stage oxidation, which, combined with the adsorption effect of activated carbon, improves quality of the effluent water.