Study On Degradation Mechanism Of Aniline By Persulfate Activated By Metal Ions

Aniline,also known as Anilin,is an important basic organic chemical raw material.In 2015,China’s aniline production capacity totaled 3.78 million tons.In 2003,the amount of waste aniline discharged into the environment in various ways around the world was about 30Kt,and the current data is still rising.Due to the toxicity and potential carcinogenicity of aniline substances to ecological organisms,China has listed it as a priority environmental control pollutant as early as 1989,and the US EPA has also listed it as one of the key control substances.The host of aniline in the environment should include water bodies,soil and specific contaminated sites.Aniline black drugs produced from aniline are widely used as collectors for non-ferrous metal（Cu,Pb,Zn）sulfide ores.The amount used during the beneficiation process is huge,and the secondary product of degradation is aniline.In addition,aniline in printing and dyeing wastewater was also seriously exceeded.Among the many existing methods for treating organic pollution,advanced oxidation processes can deal with a variety of toxic and organic pollutants and can completely destroy many emerging concerns such as natural toxins,pesticides,dyes and other harmful pollutants.However,biodegradation and physical repair methods cannot be applied on a large scale due to problems in energy consumption,operation,and environmental requirements.Chemical oxidation,especially the Advanced Oxidation Process（AOP）,is one of the best technologies that can degrade specific contaminated sites such as water bodies.Among the many existing methods for controlling organic pollution,chemical oxidation,especially advanced oxidation process（AOP）,is one of the best technologies that can degrade specific polluted sites such as water bodies.The study used three metal ions(Fe²⁺,Co²⁺,Ag⁺)to activate SPS（sodiumperoxodisulfate）and PMS（potassium bisulfate）,respectively,and explore the effect of metal ion concentration,oxidant concentration,initial reaction pH,temperature,and light on the degradation of aniline.The optimal degradation conditions of the 8system with three metal ions and no combination of metal ions and two oxidants were screened out,and the mineralization rate of the reaction of the 8 system for 180 min was detected,and the relationship between the degradation rate and the mineralization rate was explored..The effects of anions on the degradation of the system were investigated by anion experiments.The free radical quenching experiment was used to explore the free radicals involved in the reaction,and GC/MS was used to identify the degradation products,and the degradation pathway and mechanism were inferred.The experiments show that the PMS/Co and SPS/Ag systems show the best degradation effect in each system,especially the PMS/Co system(PMS,Co²⁺concentration of 5,0.25mM respectively)can almost completely degrade the initial concentration in 120min It is a 102 ppm aniline solution.The anion experiments prove that Cl^-promotes the PMS/Co system.Free radical experiments prove that hydroxyl radicals and sulfate radicals work together in the degradation of aniline and that sulfate radicals play a leading role.Analyze the aniline degradation pathways reported in the report and the experimental results in this study.It is speculated that aniline produces p-benzoquinone through various methods,and then decomposes into maleic acid,succinic acid,oxalic acid,formic acid,etc.,and finally the small molecule carboxylic acid is mineralized Carbon dioxide and water.This subject has confirmed to some extent the feasibility of metal ion-activated persulfate to degrade mine and printing and dyeing wastewater.However,in view of the complexity of organic chemicals and metal ions in actual mine wastewater,much work remains to be done in this research.