Magnetically Enhanced Catalytic Oxidation Technology And Its Application Study On Refractory Wastewater

With the rapid development of the national economy,the chemical industry has also caused serious environmental pollution.The chemical industry has many processes,complicated processes and diversified products.The chemical wastewater has the characteristics of large production volume,complex composition and high concentration of pollutants,which seriously threatens the ecological environment.The development of new technologies for efficient and low-cost chemical wastewater treatment has become one of the current research priorities.In this paper,two kinds of refractory chemical wastewaters,such as refined cotton biochemical tail liquid and electroplating mixed wastewater,were used as research objects.COD,turbidity,color and ammonia nitrogen/COD,Ni²⁺,Cu²⁺and Cr⁶⁺concentrations were used as the main pollution indicators.Magnetic field enhanced Fenton,ferrous activated sodium persulfate,magnetic field enhanced ferrous activated sodium persulfate and microelectrolytic coupled magnetic field to strengthen Fenton process as a treatment method to explore the feasibility of treating these two types of wastewater;single factor experiment The method determines the optimal processing parameters of each process.The main research conclusions are as follows:?1?For refined cotton biochemical tail liquid?organic wastewater?:Using Fenton oxidation method,the overall treatment effect was best under the conditions of initial p H=3,m?H₂O₂?/COD=1.5,n?H₂O₂?:n(Fe²⁺)=5.0 and reaction time40min:COD value,The turbidity value,the chromaticity value,and the ammonia nitrogen removal rate were classified into 90.0%,93.8%,90.0%,and 38.7%.Based on the best processing parameters of Fenton oxidation method,the magnetic field enhanced Fenton oxidation method is used.Under the condition of t=30min and magnetization current A=150A,the overall treatment effect was best:COD value,turbidity value,color The value and ammonia nitrogen removal rate were 92.5%,94.8%,92.9%,and39.3%.The treatment was carried out by ferrous activated sodium persulfate oxidation method,and the overall treatment effect was obtained under the conditions of initial p H=6,m(S₂O₈^2-)/COD=3.0,n(Fe²⁺)/n(S₂O₈^2-)=1.0,reaction time 40 min was best:COD value,turbidity value,chromaticity value,ammonia nitrogen removal rate were 84.6%,95.6%,78.8%,35.6%.Based on the optimal treatment parameters of ferrous activated sodium persulfate oxidation method,the magnetic field enhanced ferrous iron activated sodium persulfate oxidation method was used for treatment.Under the conditions of t=20min and A=125A,the overall treatment effect was the best:COD value,The turbidity value,chromaticity value,and ammonia nitrogen removal rate were 89.9%,96.7%,88.0%,and 38.7%.?2?For electroplating mixed wastewater?heavy metal wastewater?:The Fenton oxidation method was used to treat the whole process at the initial p H=3,m?H₂O₂?/COD=2.0,n?H₂O₂?:n(Fe²⁺)=2.0 and the reaction time of 50 min.The overall treatment effect was best:COD,Ni²⁺The removal rates of Cu²⁺and Cr⁶⁺are 88.6%,80.9%,86.5%,and 35.9%.Based on the best processing parameters of Fenton oxidation method,the magnetic field enhanced Fenton oxidation method was used.Under the conditions of t=35min and A=100A,the overall treatment effect was the best:COD,Ni²⁺,Cu²⁺,Cr⁶⁺removal rate were divided.91.6%,83.4%,89.2%,33.5%.The water was treated by the magnetic field enhanced Fenton oxidation method and treated by micro-electrolysis.The overall treatment effect was best under initial p H=3,reaction time 3h and sufficient aeration conditions:COD value was 35.23mg/L,removal rate was 55.9%;The concentration of Ni²⁺was 0.24 mg/L,the removal rate was 98.7%,the concentration of Cu²⁺was 0.42 mg/L,the removal rate was 91.3%,the concentration of Cr⁶⁺was 7.24 mg/L,and the removal rate was 97.3%.The overall treatment effect of the Fenton system is better than that of the ferrous activated sodium persulfate oxidation system.The treatment efficiency of the two types of oxidation methods under magnetic field strengthening conditions is greatly improved;the separate Fenton and magnetically enhanced Fenton oxidation technologies can The treatment of the refined cotton biochemical tail liquid meets the standard,but only the COD index of the electroplating mixed wastewater treatment effluent reaches a certain discharge standard;the magnetic strengthening Fenton and the micro-electrolytic coupled oxidation technology are more effective in treating the electroplating mixed wastewater,and the treated effluent is treated though Only the content of Ni²⁺and Cr⁶⁺did not reach the first-class emission standard,but the overall removal rate was also 99.8%,98.2%,and the concentration was 0.24mg/L and 7.24mg/L.