Adsorption Efficiency And Mechanism Of Tetracycline Antibiotics On Fe-oxide-coated Cu Oxides Hollow Sphere

The pollution of antibiotics is becoming more and more serious because of the increasing use of antibiotics.The environmental problem of tetracycline antibiotics is urgent.Tetracycline antibiotics are often used as feed additives,it can enter the environment in the form of excrement and pose a health risk to humans.Adsorption method has the advantages of simple equipment,simple operation,strong environmental adaptability and good purification effect for high concentration organic polluted sewage.Metal oxide adsorbent has the advantages of high adsorption capacity,easy separation and easy regeneration.This experiment aims to solve the pollution problem of tetracycline antibiotics.On the basis of the previous research results of the scientific research team,an adsorbent with good adsorption effect on tetracycline antibiotics--iron-loaded copper oxide hollow ball(FCOHS)was made.The removal mechanism and adsorption properties of FCOHS to tetracycline antibiotics were also studied.The main research contents and results are as follows:1.Using binder APTMS,ferric oxide tetroxide was bonded to the surface of cuprous oxide hollow ball precursor prepared by low temperature liquid phase method(FCOHS).After that,the cuprous oxide powder was bonded to the surface of the precursor iron tetroxide by APTMS.The adsorption effect of the two adsorbents and the dissolution of iron and copper ions in the adsorption reaction were compared.The adsorbent with the theoretical ratio of Cu:Fe=5:1 of FCOHS adsorbent was selected for this reserch.2.The characterization results of XRD,BET,VSM,TGA,FTIR,XPS,SEM and TEM can reveal the microscopic morphology and surface characteristics of the adsorbent.The characterization results are roughly as follows: FCOHS adsorbent is mainly compos-ed of Cu,Fe,C,O four elements,in which Cu: Fe=5.4:1 reached the expected preparation ratio.The results of ?=-4.4mv~-45 mv showed that the adsorbent was negatively charged and had no isoelectric point in the range of pH=3~10,indicating that the adsorbent was easy to absorb positively charged pollutants.The crystal structure of adsorbent is obvious and the surface is rich in hydroxyl groups.3.When the concentration of tetracycline antibiotics was 250mg/L,the adsorption of tetracycline antibiotics by the iron-bearing copper oxide hollow ball was mainly chemical adsorption.After comparing the three adsorption isotherm models,it was found that the adsorbents and adsorbents were correlated when the adsorption reaction occurred.The fitting results showed that the adsorption capacity of tetracycline and oxytetracycline was 1600.9mg/g and 1398.7mg/g,respectively.The adsorption scale of FCOHS for tetracycline/oxytetracycline showed a trend of gradual decline with the increase of pH.When pH=6 and pH=7,the adsorbent had a high adsorption capacity for tetracycline antibiotics,and the dissolution concentration of copper ions met the national drinking water standard.Low pH will affect the stability of adsorbent,high pH adsorption effect poor.4.The adsorption mechanism of iron and copper composite oxide hollow spheres to removle tetracycline antibiotics is mainly due to the complexation reaction between tetracycline antibiotics and oxygen-containing groups on the adsorbent surface.At the same time,because of the tetracycline class of antibiotics for Cu(?),Cu(II),Fe(?)and Fe(?)has the strong affinity,when Cu adsorption reaction(?)and Cu(II)and complexation reaction taking place between tetracycline/terramycin,make FCOHS of tetracycline compared with other adsorbent adsorption effect is better.5.0.1mol/LNaOH solution has good elution performance for FCOHS adsorbent.After five cycles of recycling,the readsorption rates of tetracycline and oxytetracycline were 73.4% and 75.1%.