Treatment Of Coking Wastewater Using New Fly Ash Based Catalyst Coupled UV-Fenton-MBR

A kind of fly ash zeolite [AlSiO₄] ₆-4H₂O with high cation exchange capacity（CEC） and adsorption performance was synthesized using hydrothermal synthesis method, then two different type of fly ash zeolite supported Cu-Fe catalysts were made by impregnation and coprecipitation, and the optimum catalyst was used to treat coking wastewater. The structure of fly ash zeolite and catalysts were characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM）. We studied the cooperative mechanisms between Cu and Fe.Synthesis of zeolite showed that:the optimum synthetic condition for fly ash zeolite is that:Si/Al 0.906, crystallization temperature 141℃, crystallization time 9.87 h. XRD and SEM characterization showed that chemical formula of synthetic zeolite was Na6 [AlSiO₄] 6’4H₂O. The performance of zeolite could been significantly improved after replacing synthetic liquid with 2 mol/L NaCl solution.Synthesis of bimetallic catalysts showed that:the catalyst made by impregnation method was better than co-precipitation method at degradation of methylene blue（MB）; Not only did the Cu-Fe bimetallic catalyst has higher photocatalytic activity and faster pace than Fe2+/H₂O₂, but also it broaden the range of pH from 2-4 to 2-12, which certified the existence of synergy between Cu and Fe, following we discussed the synergy mechanism in depth; After being recycled four times the removal of MB is still as high as 70.4%.Study on treatment of UV-Fenton to cokes wastewater showed that:removal efficiencies of UV-Fenton-MBR to organics, SCN-, and CN- were over than 92%, while NH₄⁺-N was 56.89%, removal efficiencies of organics were reduced with the extension of running time, but the removal rate of SCN-, CN- and NH4+-N were almost unchanged.The findings are based on waste utilization, provide a new way for efficient but low cost utilization of fly ash, salt water and cokes wastewater low cost and resource degradation ash, salt water and high coking wastewater, offer a theoretical basis for in-depth understanding of the zeolite hydrothermal synthesis, preparation of catalyst and synergistic effect mechanism between Cu and Fe in degradation of organic matters process.