Study On Removal Mechanism Of Tetracycline And Arsenic By Copper-manganese Composite Oxide Under Catalytic Oxidation

In recent years,with the rapid development of livestock and poultry breeding industry,the pollution of livestock and poultry wastewater is also intensified.How to effectively remove tetracycline antibiotics and heavy metals from livestock and poultry wastewater has become the most urgent problem to be solved at present.In this paper,the adsorption of tetracycline antibiotics and arsenic by copper-manganese complex oxide?CMBO?was studied.The catalytic performance of CMBO was used to activate sodium persulfate to remove tetracycline antibiotics,and the adsorption performance of CMBO was used to remove arsenic.The mechanism and adsorption properties of CMBO in the removal of tetracycline and arsenic were analyzed by means of different aspects of CMBO.The main research contents are as follows:?1?By optimizing the preparation conditions of CMBO,select the best CMBO ratio is Cu:Mn=3:1.The catalysts were characterized by BET,TEM,SEM,TGA,FTIR,XRD,XPS and EPR.It is found that CMBO of Cu:Mn=3:1 is a kind of macroporous and mesoporous material with large specific surface area,which can reach 212.2848m2/g.XPS analysis shows that it has good catalytic performance and can activate sodium persulfate?PS?.?2?Tetracycline and arsenic were removed by catalytic degradation experiment.In the catalytic degradation experiment,the removal way of tetracycline is mainly to use CMBO to activate PS to produce oxidizing free radicals to achieve the removal effect.However,because CMBO itself has a certain adsorption effect,tetracycline will also be adsorbed in the process of catalytic oxidation.The main way to remove arsenic is to remove arsenic by CMBO adsorption.In the process of catalytic oxidation,the CMBO activated PS produced free radicals with oxidation,and the AS?III?was oxidized to AS?V?and adsorbed under the action of CMBO.In addition,when tetracycline and arsenic exist at the same time in the reaction system,both of them will inhibit and reduce the removal efficiency.In the ion interference experiment,it is found that the removal of arsenic can be inhibited when PO₄^-exists in the solution.?3?It can be analyzed by EPR.In the catalytic oxidation reaction,two strong oxidizing free radicals,sulfate radical and hydroxyl radical are produced.In the process of catalytic degradation by free radical quenching,the radical of sulfate plays a leading role in the course of the reaction.Using the time-of-flight mass spectrum analysis,there are two approaches to CBOs degradation of TC:The first step:TC converts macromolecules into small molecules through dehydration,demethylation and dealkylation.The second step:TC is oxidized by strong oxidizing free radicals in the reaction process,which is changed from macromolecule to small molecule by chemical bond breaking.