Multi-dimensional Material Coupled Transition Metal Catalytic Material Design And Its Removal Of Organic Pollutants In Water

Tetracycline,as one of the most widely used antibiotics at present,has a relatively stable structure.It is difficult to completely remove it by using conventional water treatment technology in the process of water treatment,resulting in unsatisfactory water treatment effect,so effective technology is needed to effectively carry it out.degradation.Advanced oxidation technology(AOPs),as a new water treatment technology,can effectively degrade refractory organics.Therefore,this study chose to use advanced oxidation technology when degrading tetracycline.Among the advanced oxidation technologies,Fenton oxidation technology is the most widely used in the water treatment process,but Fenton oxidation technology also has its obvious shortcomings,so the advanced oxidation technology based on free radicals has received more and more attention in recent years.According to the different types of free radicals,it can be divided into hydroxyl radicals and sulfate radicals.Hydroxyl radicals are generally generated by the decomposition of ozone,and sulfate radicals are generally generated by the decomposition of persulfate.Persulfate is relatively stable at room temperature and is difficult to generate corresponding free radicals.Therefore,it needs to be properly activated.Active peroxodisulfate(PDS)such as transition metals and carbon materials degrades organic pollutants.Due to its excellent degradation performance,It has broad application prospects in water treatment.In this paper,graphene supported transition metals copper and manganese and cobalt manganese spinel were selected to activate peroxodisulfate to catalyze the degradation of tetracycline.(1)In this study,transition metals(such as copper and manganese)were loaded onto graphene by the solid phase grinding method and wet impregnation.And the best catalyst was selected through the tetracycline degradation experiment.The experimental results show that the catalytic effect of s-Cu2.5Mn2.5Ox/hG is relatively excellent,the degradation rate of tetracycline in the water body can reach 99.4%.Through a series of characterization results analysis,it is found that there are two main ways for carbon-based catalysts to degrade tetracycline,namely,free radical pathway and non-radical pathway.Among them,graphene can activate PDS through free radical pathways,and non-radical pathways can also activate PDS,while transition metals rely on hydrogen bonds and persulfate to generate free radicals to further degrade tetracycline.Through the analysis,we found that the two transition metals have only one active center.The active center in this study is manganese.The presence of copper further improves the covalency of the Mn-O bond and promotes the valence of the elements.Conversion,thereby generating more free radicals to degrade tetracycline.And by LC-MS analysis of the intermediates produced in the process of catalytic degradation of tetracycline.(2)Through the experiment on carbon-based materials loaded with transition metals to activate PDS to degrade tetracycline,it can be known that carbon-based materials have obvious defects in the process of catalytic degradation of tetracycline.Therefore,the catalyst needs to be further optimized.After reading the literature,the cobalt manganese spinel was finally selected.It can not only overcome the adsorption performance of carbon materials far higher than the catalytic performance,but also has good cycle performance.In the experiment,the cobalt-manganese spinel was prepared by a simple reduction method.Choosing different reducing agents can control the crystal strength of spinel.Through the experiment of catalytic degradation of tetracycline,it can be seen that the spinel prepared by different reducing agents has excellent catalytic degradation effect.CoxMnyOz(C)has the best catalytic degradation effect,which can reach 99.6%.At the same time,BET and EPR characterization analysis futher proved the reasons for the differences in the catalytic effects of different catalysts.At the same time,the differences in the degradation processes of CoMn2O4(S),CoMn2O4(P)and CoxMnyOz(C)were analyzed by LC-MS.In this paper,the study of preparing catalysts to activate PDS to degrade tetracycline provides a new idea for the design of functional catalytic materials,which is of great significance to the control of tetracycline and other organic pollutants in water in the future.