Degradation Of Tetracycline In Water By Activated Persulfate With Lentinus Edodes Biomass Carbon Composite

Tetracyclines are the most widely used broad-spectrum antibiotics in the world.However,it is not completely metabolized and decomposed in the organism,so part of the tetracycline will be excreted into the water.The residual tetracycline in the water can induce the genetic variation of microorganisms and lead to the emergence of drug-resistant pathogens,which is a potential risk to human health.Therefore,a method for efficiently degrading tetracycline in water needs to be sought.Fenton-like advanced oxidation technologies（AOPs）using sulfate radicals（·SO₄^-）as active substances are a powerful oxidizing technology.In this paper,waste shiitake rhizomes were used as biomass raw materials（LBC）,and tetracycline hydrochloride（25 mg/L）was used as the target pollutant.A catalytic material was synthesized by modifying it,and the degradation performance of tetracycline in water under the assistance of sodium persulfate and visible light was studied,and the degradation mechanism was explored,and some research results were obtained.The result is as follows:（1）Fe₃O₄@LBC composites were prepared by impregnation-calcination method and characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）and Brunauer,Emmett,Teller specific surface area method（BET）,etc.The degradation performance of Fe₃O₄@LBC and sodium peroxodisulfate（Na₂S₂O₈）on tetracycline hydrochloride under visible light irradiation was investigated.The results showed that the Fe₃O₄@LBC/Na₂S₂O₈/Visible light system had a degradation efficiency of 85%for tetracycline within 120 min,which indicated that the catalyst had strong catalytic activity.In addition,the composite also exhibits high stability and excellent cycle repeatability.After five consecutive cycles,the degradation efficiency of tetracycline was still not less than 80%.（2）A novel CuFe₂O₄@LBC composite magnetic catalytic material was successfully synthesized by a simple hydrothermal method.The X-ray diffraction（XRD）patterns of the synthesized composites confirmed the successful loading of CuFe₂O₄ on the surface of the mushroom biomass carbon.The properties of the samples were further characterized by scanning electron microscopy（SEM）,Fourier transform infrared spectroscopy（FTIR）and X-ray photoelectron spectroscopy（XPS）.The tetracycline removal rate of CuFe₂O₄@LBC composites reached 85%within 90 min,which was much higher than that of pure CuFe₂O₄ or LBC.After five cycles of experiments under the same conditions,it still has good degradation ability to the fifth catalytic degradation experiment,and the degradation rate of tetracycline can still reach 80%.Due to the good magnetic properties of CuFe₂O₄@LBC composites,the catalytic materials can be magnetically separated by an external magnetic field.（3）Boron-doped mushroom biomass carbon（B@LBC）was synthesized by impregnation-calcination method with boric acid as the precursor.The morphology and element valence state of the material were analyzed by SEM,XPS,and BET.The construction of a photocatalytic system,a chemical catalytic system,and a photo-chemical catalytic system was mentioned to verify that the material has good degradation performance in the heterogeneous photocatalytic system.With the help of visible light and sodium persulfate,the removal rate of tetracycline reached 98%.After three cycle experiments,it is known that the material has excellent stability,and the removal rate of tetracycline in the third catalytic degradation reaches 82%.