Study Of Catalytic Ozonation Of Coking Wastewater By Resin Catalyst

The state published the "Emission standard of pollutants for coking chemical industry" in 2012,which the emission standard of coking wastewater is more stringent.Conventional biochemical methods for effluents are difficult to meet the standard,therefore it is necessary to explore advanced methods for coking wastewater.In this paper,using D001 as carrier,transition metal ions Fe2+,Mn2+,Cu2+ were immobilized on the carrier by immersion method for the preparation of D001-Fe,D001-Mn and D001-Cu,and D001-Cu was modified to obtain D001-Cu-M.Scanning electron microscopy,BET analysis,EDS spectroscopy,FTIR spectra and thermos-gravimetric analysis were used in this study for structure characterization of D001 and the four catalysts.The four catalysts were used to degrade naphthalene and 2-naphthol through catalytic ozonation.The factors including preparation conditions,pH value,dosage of catalyst,dosage of ozone,concentrations of pollutants,flow rate of wastewater,and temperature on the pollutants removal were investigated.According to the results above,the effects of the four catalysts for coking wastewater,and finally kinetic fitting were studied.The main conclusions were as follows:(1)D001-Cu,D001-Fe and D001-Mn were prepared by impregnation method and D001-Cu was modified,and orthogonal test was carried out.The influence degree of various factors on the preparation of D001-Cu-M catalyst was: active component impregnation liquid concentration > solid-liquid ratio > pH.The four catalysts were applied to the degradation of naphthalene,2-naphthol and coking effluent in single factor oxidation experiments.The results revealed that all the four catalysts showed high catalytic effects,and the preparation conditions of the catalysts were different for different pollutants.(2)D001-Mn(1 mol/L MnSO4,1:2 solid-liquid ratio)showed the highest removal rate for naphthalene,which was 95.22%.And reusability of the catalyst was excellent.The optimum reaction conditions were as follows: 40 ?,the initial pH value was 7,ozone dosage was 0.036 mg/min,the initial concentration of naphthalene solution was 15 mg/L,naphthalene solution flow rate was 4 mL/min,and catalyst dosage was 1.6 g/L.Under the optimum conditions,the catalytic ozonation reaction ofD001-Mn was in accordance with quasi-first order kinetics,whose constant was 0.14,and R~2 = 0.965.(3)D001-Mn(0.5mol/L MnSO4,1:5 solid-liquid ratio)showed the highest removal rate for 2-naphthol,which was 94.29%.Reusability of the catalyst was excellent.The optimal reaction conditions were as follows: 40 ?,the initial pH value of the solution was 7,ozone dosage was 0.006mg/min,the initial concentration of2-naphthol solution was 100 mg/L,the flow rate of 2-naphthol solution was 4mL/min,and catalyst dosage was 2 g/L.Under the optimum conditions,the catalytic ozonation reaction of D001-Mn was in accordance with quasi-first order kinetics,whose constant was 0.14,and R~2 = 0.998.(4)D001-Cu-M(1mol/L CuSO4,1:5 solid-liquid ratio,pH=10)showed the highest effect for biochemical effluent of coking wastewater.The removal rate of COD,ammonia nitrogen,TN,and chroma were 51.53%,30%,70.68%,and 80%,respectively.Reusability of the catalyst was excellent.The optimum reaction conditions were as follows: pH value of initial wastewater,D001-Cu-M dosage was 4g/L,ozone dosage was 0.084 mg/min and wastewater flow rate was 4 mL/min.Under the optimum conditions,the catalytic ozonation reaction of D001-Cu-M was in accordance with quasi-first order kinetics,whose constant is 0.02,and R~2 = 0.967.