The Degradation Of Aniline By Persulfate With Different Supported CoFe₂O₄ Catalysts

With the improvement of the discharge standards for water pollutants in the printing and dyeing industry,especially for the aniline,which is not allowed to be detected in the GB4287-2012.Therefore,aniline becomes one of the difficulties.How to efficiently remove aniline in the tail water of printing and dyeing wastewater has attracted widespread attention.In this experiment,CoFe₂O₄ catalyst was prepared by chemical co-precipitation method and high-temperature calcination method,loaded with sodium alginate to catalyze sodium persulfate.In this way,the advanced oxidation system was constructed to degrade aniline simulated wastewater.This paper mainly carried out the experiment of CoFe₂O₄ loaded on activated carbon and sodium alginate respectively,the degradation of aniline by persulfate with different supported CoFe₂O₄ catalysts,and ion effects in advanced oxidation system.The results show:（1）The best preparation conditions of CoFe₂O₄ loaded on activated carbon were as follows:The addition amount of Fe²⁺,Fe³⁺,Co²⁺was 0.04mol/L,0.04mol/L and 0.02mol/L respectively,the addition amount of carbon was 60g/L,the calcination temperature was550℃,calcination time was 2h.The catalyst was characterized by SEM,TEM,EDS and XRD,which indicated that the catalyst was porous.（2）The best preparation conditions of CoFe₂O₄ loaded on sodium alginate were as follows:The addition amount of sodium alginate was 10 g/L,the addition amount of calcium chloride was 10 g/L,the addition amount of catalyst loaded on carbon was 40 g/L,and the addition amount of sodium silicate was 25 g/L.The catalyst was characterized by SEM,TEM,EDS and XRD,which indicated that the catalyst had porous particle structure.（3）The catalyst of CoFe₂O₄,which is loaded on sodium alginate,and sodium persulfate composed an oxidation system to degrade aniline.The best conditions were as follows:The reaction time was 2h,the amount of catalyst was 5g/L,the amount of sodium persulfate was0.2g/L.The degradation rate of aniline is more than 99.4%,aniline concentration is lower than0.03mg/L,and the aniline is completely degraded in the UV spectrum detection reaction.And the removal rate of aniline can still reach over 90%after repeated use of the catalyst for 5times,indicating that the catalyst has good repeatability.（4）Through the ion experiment,the effect of anions and cations on the degradation of aniline was studied,and several major anions and cations were investigated to the degradation of aniline.The conclusions are as follows:Ca²⁺and Co₃^2-can inhibit the degradation of aniline,while Mg²⁺,K⁺,HCO₃^-,SO₄^2-can promote the degradation of aniline,Na⁺and Cl^-have little effect on the degradation of aniline.