Carbothermal Reduction For Synthesis Of NZVI/Carbon Fiber In Application Of Antibiotics And Uranium Decontamination

Nano zero-valent iron（nZVI）is widely used in the removal of environmental pollutants,but it is easy to be oxidized and agglomerated.In this study,the carbothermal reduction of resource-recovered cotton fiber was conducted for the synthesis of nZVI supported on cotton carbon fiber（nZVI/CFs）to address the agglomeration and oxidation of nZVI.nZVI/CF was used to degrade levofloxacin（LEV）by peroxymonosulfate（PMS）activation and treatment of uranium containing wastewater by synergistic adsorption and reduction.The researches content are as follows:（1）The nZVI concentration and morphology were conveniently adjusted by soaking cotton fiber in ferric nitrate solutions of various Fe³⁺concentrations.The carbothermal reduction of the cotton fiber at 900°C contributed to the reduction of Fe³⁺into nZVI（nZVI/CF-900）.The morphology and composition of the prepared nZVI/CF-T-s were analyzed by XRD,SEM,BET&BJH,XPS characterization.It was found that nZVI was successfully dispersed on the cotton carbon fiber.（2）Synergistic adsorption and peroxymonosulfate（PMS）activation using nZVI/CF for removing levofloxacin（LEV）are reported herein.Favorable adsorption of nZVI/CF-900-0.3 to LEV facilitated LEV degradation under PMS activation.Approximately 93.83%of LEV（C₀=20 mg/L）was removed within 60 min with 0.2 g/L of the catalyst and 1 m M PMS.It was preferable to use nZVI+CF-900 to activate PMS for degrading LEV,thus confirming the favorable effect of LEV adsorption on further degradation.EPR and mechanism research experiments are confirmed that·SO₄^-played an important role in LEV degradation in the presence of PMS.The possible degradation pathway of LEV was put forward according to the intermediate products by LC-MS.The nZVI/CF-900-0.3 exhibited excellent long-term stability given that it was able to activate PMS after it was stored for 6 months.This study reveals the adsoption and catalytic degradation behavior of LEV on nZVI/CF,which facilitates in understanding the degradation processes and mechanism of other antibiotics and to provide the possibility of application for nZVI/CF in practical wastewater treatment.（3）According to nZVI has strong reductive ability,nZVI/CF-900-0.3 will be used for the removal of uranium-containing wastewater.nZVI/CF-900-0.3 applied to the treatment of uranium-containing wastewater demonstrated that the maximum removal of U（VI）was 95.63%at a dosage of 0.5 g/L,p H value of 6,and initial U（VI）concentration of 20 mg/L.The pseudo-second order and Langmuir adsorption isothermal model was comfirmed to the adsorption process well.The mechanism of nZVI/CF-900-0.3 removal of uranium is confirmed by SEM-maaping and XPS characterization.nZVI/CF-900-0.3 still exhibited obvious adsorption performance to uranium-containing wastewater after exposuring in air for 35 days and 60 days.Therefore,nZVI/CF-900-0.3 has great development potential in the treatment of uranium-containing wastewater.（4）The removal of LEV-U（VI）composite pollutants through adsorption and peroxymonosulfate activation using nZVI/CF-900-0.3.Through preliminary investigation,nZVI/CF-900-0.3 can effectively remove 20 mg/L LEV-U（VI）mixed solution by activating1m M PMS.The removal efficiency of LEV and U（VI）is 96.52%and 97.31%,respectively.Therefore,based on outstanding catalytic degradation ability and adsorption and reduction ability,nZVI/CF-900-0.3/PMS system has potential application value in complex environmental polluted watertreatment.