| Printing and dyeing wastewater in the refractory industrial wastewater accounted for a larger proportion of its water quality and quantity changes with large,deep color,high COD content,alkaline,heavy metal ions,toxic characteristics,the use of conventional physical and chemical methods and Biological treatment method is relatively limited,and the treatment effect is not satisfactory.Fenton oxidation and Fenton-like oxidation reaction fast,good treatment effect,stand out in the treatment of printing and dyeing wastewater,it is widely used in printing and dyeing wastewater treatment.However,the defects of the narrow pH range of conventional Fenton oxidation and most Fenton-like oxidation processes in the treatment of printing and dyeing wastewater have not been solved yet.Based on our predecessors' research,Fe3O4-MnO2 composite material was prepared and loaded on the surface of powdered activated carbon.The ability of MnO2 to catalyze H2O2 was used to improve the narrow pH range of Fenton-like oxidation process.Fe3O4-MnO2-PAC Fenton system of printing and dyeing wastewater treatment study to explore the method of printing and dyeing wastewater treatment effect.For printing and dyeing wastewater and other refractory organic wastewater to provide efficient treatment methods to speed up the realization of Fenton oxidation technology in the printing and dyeing wastewater treatment on the promotion and application.Fe3O4-MnO2 composites were prepared by chemical coprecipitation method and loaded onto the PAC surface with different ratio.XRD and EDS analysis showed that Fe304-Mn02 was supported on the surface of powder activated carbon in 1#1:1,2#2:1 and 3#3:1 Fe3O4-MnO2-PAC composites.Fe3O4-MnO2-PAC composite oxide with a nearly spherical structure evenly supported on the surface of powdered activated carbon.The Zeta potentials of 1#,2#and 3#composites show that the three composite colloids have good stability and are not easily agglomerated.The catalytic activity of the composites showed that 1#1:1,2#2:1 and 3#3:1 Fe3O4-MnO2-PAC composites all catalyzed the formation of Fenton-like system by H2O2.Among these catalysts,Fe3O4-MnO2Orthogonal test and single factor test showed that Fenton system with 1#1:1 Fe3O4-MnO2-PAC composite catalyst was better than other ratios in the treatment of methylene blue simulated printing and dyeing wastewater.For the methylene blue simulation with a concentration of 100mg/L When the dosage of H2O2 is 0.8Qth,the dosage of Fe3O4-MnO2-PAC catalyst is 0.8g/L,the initial pH is 3,the temperature is 25 ? and the reaction time is 120min,the effluent treated by this Fenton system Methylene blue removal rate of nearly 100%,the water was colorless and transparent,COD effluent concentration 165mg/L dropped to 23.97mg/L,the removal rate was 85.47%.Fenton system reaction kinetics study showed that:Fe3O4-MnO2 Fenton system for printing and dyeing wastewater degradation process in line with the apparent first-order reaction kinetics.The reaction rate of Fe3O4-MnO2 Fenton system on the degradation process of printing and dyeing wastewater was less affected by the initial pH.The rate of degradation of printing and dyeing wastewater was not affected by the initial pH within the range of pH = 2-5.Reaction temperature increases,the reaction rate increases,Fe3O4-MnO2-PAC catalyst dosage and H2O2 dosage on the reaction rate of the same trend.The influence of dyeing and finishing auxiliaries on the dyeing wastewater treatment with Fenton system was studied under the condition of design and experiment.The results showed that NaCl,Na2CO3 and Na2S could inhibit the degradation of printing and dyeing wastewater in this kind of Fenton system and the inhibition of Na2S Which is followed by NaCl followed by Na2CO3 and Na2SO4,which has no obvious inhibitory effect on the degradation of printing and dyeing wastewater by Fenton system.The presence of Cu2+and Zn2+ has no inhibitory effect on the treatment of methylene blue wastewater by Fenton system.Pb2+ Waste water has a certain degree of inhibition.The presence of surfactants inhibits the catalytic oxidation of Fenton-like systems.Fe3O4-MnO2-PAC Fenton oxidation is a worthy promotion of printing and dyeing wastewater treatment technology.Compared with the conventional Fenton,the pH range of the reaction can be broadened,the secondary pollution of iron ions can be avoided,the subsequent treatment cost can be reduced,and the catalyst can be reused.For accelerating the development of the Fenton-type catalytic oxidation technology and accelerating the implementation of Fenton-like oxidation technology in printing and dyeing The promotion of wastewater treatment has practical significance. |
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