Catalytic Ozonation Of Aniline In Water By FeOOH Or Si-FeOOH

Aniline is an important chemical raw material;however,aniline has a strong toxicity,and seriously hazardous to human health and the environment.With the increasing demand of aniline,the treatment of aniline wastewater has become a hot topic in the world.In recent years,many methods are used to treat the aniline wastewater,such asphysical methods,chemical methods and biological methods.The physical methods can not completely remove aniline in the wastewater.It is difficult to promote in a wide range for the biological treatment because of poor performance of biological degradation of Aniline.And many people focus their attentions on the chemical treatments for their high efficiency in removing Aniline.Ozone,as a kind of green and strong oxidizing agent,has a certain practical value in the application of organic wastewater.In order to make up for the deficiency of ozone to degrade aniline,such as no completely organic mineralize,relatively low organic matter removal and ozone utilization efficiency,in this paper,a green and environmentally friendly catalytic oxidation system(FeOOH/O3 system)was used.Treatment of aniline wastewater using ozonation combined with prepared hydroxyl ferric oxide(FeOOH)was conducted,comparison of the effects on the degradation of aniline by FeOOH/O3 system and O3 system were discussed.The results showed that the FeOOH/O3 system has better efficiency than O3 system,showing higher mineralization degree.The effects of factors including the oxygen intake flow,aniline initial concentration,pH and catalyst dose were also investigated in detail.Under the condition of O2 intake flow 30 L/h,initial concentration 180 mg/L,pH value of 7,catalyst dosing quantity 3g/L,reaction time 10 min,the removal rate of aniline can reach 96.9%,and the COD removal rate can reach 73%.By adding free radical scavenger in the catalytic process,the catalytic ozonation reaction was obviously inhibited,which proved that the degradation of aniline by FeOOH/O3 followed the free radical reaction mechanism.The Si-FeOOH for catalytic ozonation of aniline was prepared by Si doping in order to enhance the mechanical strength.Effects of the factors on the aniline removal rate were studied.The stability of the reused catalyst and the condition of Fe dissolution were also researched.The results showed that the catalytic effect of Si-FeOOH on aniline degradation by ozonation was significant,since the aniline degradation rate by Si-FeOOH catalytic ozonation was much higher than that by ozonation and that by FeOOH catalytic ozonation.Under the optimum conditions of solution pH=11,Si-FeOOH dosage 1.0 g/L,n(Si):n(Fe)=0.55,initial aniline mass concentration 300 mg/L and degradation time 10 min,the aniline degradation rate could reach 100%;After 5 recycle times,the aniline degradation rate could still up to 97.8%,and the Fe dissolved quantity of Si-FeOOH is obviously lower than that of FeOOH.