Study On The Oxidative Degradation Of Azo Compounds

Azo-based organic compounds are collectively referred to a class of compounds which containing azo groups in the molecular structure.Azo compounds are used as dyes,which have a more extensive application to the files of textile,leather and other files.If the human body are in long term contact with the azo dyes,the reduction reaction will occurred in the metabolic process,and the carcinogenic aromatic amine compounds will be formed.If these aromatic amine substances is absorbed by the body,the symptoms such as erythema,blisters will be caused.If we handled improperly,the bacterial infection and suppuration can also be caused.After a series of effects,the structure and function of human DNA cell changes,and ultimately become the cause of human disease,causing harm to human health.Therefore,it is of great theoretical and practical significance to deal with this wastewater which containing azo dyes.Polypyrrole?PPy?is a typical conjugated polymer,which has good light,electricity,magnetic properties and electrochemical redox reversibility.The PPy is widely used in electrochemical sensors,electrochemical catalytic active materials, electroluminescence and other fields,which is one of the more studied materials in recent years.In this paper,polypyrrole was prepared by simple experimental methods and devices,and polypyrrole composites was obtained by carrier-supported polypyrrole,through carrier-loaded polypyrrole,improved the shortcomings of the polypyrrole such as easy agglomeration,solid density is small and insoluble in water,besides that,the reaction can not be completely contact with the reaction,the lower efficiency of the oxidation can also be improved.Take methyl orange and soap yellow as azo compounds,the oxidation properties of polypyrrole composites were studied by UV-vIs spectroscopy,and the main contents were as follows:1.Py and nano-SiO₂ as raw materials,polypyrrole/nano-silica?PPy/nSiO₂?composites with mass tatio of 1:1 were prepared by the oxidation of FeCl3,and used for the oxidation of methyl orange solution.The result shows that polypyrrole is more uniformly loaded onto the surface of nano-SiO₂,so that the specific surface area of PPy increases,and then inhangcing the oxidative activity of the composite.For the simulated wastewater which containing 12 mg/L methyl orange,oxidation was carried out for 1 hour by using PPy/nSiO₂ which is 1.0 mg/L,the removal rate of methyl orange was 94.7%.The PPy/nSiO₂ was also showed a certain catalytic effect,which can catalyze hydrogen peroxide?H2O₂?to oxidate of methyl orange.Not only to speed up the reaction rate,but also reduce the amount of PPy/nSiO₂.PPy/nSiO₂ can be recycled,and the PPy/nSiO₂ which after regeneration be recovryed,the removel rate of methyl orange can achieve the effect of the innitial use.2.Use the Py and nano-SiO₂ as the raw materials,by the oxidation of FeCl3,to prepare PPy/nSiO₂ composite which with mass ratio of 1:1,and use the composite in the oxidation reaction of soup yellow solution.The effects of pH,PPy/nSiO₂ dosage and initial concentration of soap yellow solution on the reaction were discussed,and the degradation process of soap yellow was analyzed by UV-Vis.The result shows that the PPy/nSiO₂ composites which with lager surface area has better oxidative degradation effect on soup yellow.For 1.5×10-3 mol/L sopy yellow solution,using 1.5 mg/mL PPy/nSiO₂ oxidation reaction for 1 hour,the removel rate of soap yellow reached 96.5%.When the reaction system exist hydrogen peroxide,and to achieve the same degradation effect,the amount of PPy/nSiO₂ was decreased.3.The pyrrole monomer?Py?and nano-CeO₂ were used as raw materials,PPy/nCeO₂ composites with a mass ratio of 1:1 mass ratio in the presence of sodium dodecylbenzene sulfonate?SDBS?were preparation by using FeC13 as oxidant,and used for oxidative degradation of methyl orange.The effects of the amount of polypyrrole/nano-cerium oxide?PPy/nCeO₂?composites,the amount of SDBS and the reaction acidity on the oxidation reaction were studied.The results showed that when the amount of sodium dodecylbenzenesulfonate was 2.178 g,the polypyrrole could be uniformly supported on the surface of nCeO₂,and the prepared PPy/nCeO₂ had a larger surface and had better degradation effect on methyl orange,the removel rate of methyl orange was 99.2%with using 1.0 mg/mL PPy/nCeO₂ to 12 mg/L methyl orange solution for one hour.The oxidaton degradative effect is stronger than that of polypyrrole/nano-silica?PPy/nSio2??the removel rate is 94.7%?,so the PPy/nCeO₂ composites have good oxidative degradation performance.