Preparation Of Cerium Doped Nano-zinc Oxide And Degradation Of Cephalosporin Antibiotics

At present,water pollution caused by antibiotics has became a major problem for water treatment.The antibiotics ingested by the organism eventually enter the environment and form pollution,which will cause serious harm to the ecological environment and human health.However,the treatment of antibiotics in water has gradually developed into a new research hot spot,with the introduction of new environmental pollutants.At home and abroad,there are many researches on nano-zinc oxide and its modification.It has shown good degradation effects in dye wastewater and other areas.But there are few applied researches on taking antibiotics as the target.Compared to traditional water treatment technologies,photocatalytic technology is more green.This technology applied to researches on the treatment of antibiotic contamination,can provide new ideas for the study of this kind of material degradation.It has important practical significance.The object studied optimal preparation conditions for ZnO and Ce/ZnO,and their degradation efficiency against cephalosporins.In this experiment,nano-zinc oxide was prepared by sol-gel method and characterized by XRD,SEM and FT-IR.The antibiotic degradation conditions were as follows:catalyst dosage was 50 mg;initial substrate concentration was 5 mg/L;initial pH was 7;UV light reaction was 1 h.Under these conditions,the optimal preparation conditions of ZnO nanoparticles were obtained:calcining temperature was 550℃,calcining time was 3 h,0.5 g SDBS was added.Under the same degradation conditions,the optimal preparation conditions of Ce/ZnO nanoparticles were obtained:the doping amount of cerium(nCe/nZn)was 0.05,the calcining temperature was 550℃,the calcining time was 3 h.and adding 0.4 g SDBS.The XRD results showed that the self-made nano-zinc oxide exhibit a hexagonal wurtzite structure with high crystallinity and purity.Some cerium ions that do not enter the ZnO crystal lattice existed in the form of cerium oxide.The SEM results showed that the self-made nano-zinc oxide was ellipsoid with uniform particle size and average particle size of 80 nm with good dispersity,but there are local agglomeration phenomnon.The FT-IR results confirmed that the presence of self-made catalyst ZnO cells and cerium oxide.The photocatalytic degradation of cefuroxime sodium and ceftazidime and the important process parameters affecting the photocatalytic degradation were investigated by single factor test and orthogonal test.The results showed that using ZnO as photocatalyst and cefuroxime sodium as a target,the optimal degradation conditions were obtained:the catalyst dosage was 50 mg,initial substrate concentration was 5 mg/L,initial pH was 8,and the UV light time was 80 min.The best degradation rate is 64.52%.Under the same conditions,using Ce/ZnO as photocatalyst,the best degradation rate was 77.54%.By contrast,doping rare earth cerium can improve the photocatalytic activity,the degradation rate of cefuroxime sodium increased by 13%.Using ZnO as photocatalyst,ceftazidime as the target,the optimal degradation conditions were obtained:the catalyst dosage was 40 mg,initial substrate concentration was 5 mg/L,the initial pH was 7,and the UV light time was 80 min.The best degradation rate was 62.79%.Ce/ZnO as a photocatalyst,the best degradation rate was 70.52%under the dosage was 30 mg.By contrast,doping rare earth cerium can improve the photocatalytic activity.The catalyst Ce/ZnO was used repeatedly 5 times,the degradation rate was still above 60%,which indicated that Ce/ZnO has good stability and can be recycled.