Degradation Of Acid Red 1 By Activated Peroxymonosulfate With Copper-cobalt Based Catalysts Supported By Carbon Nanofibers

Azo dyes are one of the most widely used synthetic dyes in industry.Because of high toxicity,high carcinogenicity,high stability and difficult biodegradability of azo dyes,their widesperad distribution in water have brought servious problems in the enviorment.In recent years,advanced oxidation technology?AOPs?based on sulfate radical is very popular in dye wastewater treatment due to its advantages of high efficiency,stability,low cost and non-toxicity.The key to improve AOPs technology is to study effective activated materials with one-sulfite to produce SO₄^·- and ^·OH efficiently.In this thesis,the catalytic performance and reaction mechanism of the supported catalysts prepared with Cu and Co as active components for the degradation of azo dyes were studied with the anticipation of achieving efficient activation of PMS,an oxidant commonly used in AOPs technology,and accomplishing the efficient degradation of azo dyes.Firstly,Carbon nanofiber composite membranes?Cu/Co/Co O@CNF?loaded with Cu/Co/Co O are prepared by electrostatic spinning,solvent thermal reaction and inert atmosphere carbonization.Scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray diffraction spectroscopy?XRD?and atomic absorption spectrometry?AAS?were used to characterize the morphology,structure and content of active components of Cu/Co/Co O@CNF.Taking azo dye acid red 1?AR1? as the target pollutant,the degradation performance of PMS activated by Cu/Co/Co O@CNF under different reaction conditions was systematically studied.The results showed that AR1 could be oxidized to remove more than 97.7%within 6 min at 50 mol L^-1,0.5 mmol L^-1,Cu/Co/Co O@CNF,0.175 g L^-1,298 K,and 6.5 p H.At the same time,the removal rate retained above 90.2%after 7 cycles experoments.TOC test showed that the TOC removal rate of azo dyes in Cu/Co/Co O@CNF-PMS system reached 70.5% at 60 min.Free radical capture experiments showed that reactive oxygen radicals(SO₄^·-,^·OH and ¹O₂) were generated in the process of catalytic degradation.Secondly,carbon nanofiber composite membranes?Cu Co@CNF?loaded with copper and cobalt bimetals were prepared by means of electrostatic spinning,solvent thermal reaction and reducing atmosphere carbonization.XRD,SEM,TEM and BET tests showed that the copper-cobalt nanoparticles were evenly distributed on the surface of the prepared porous carbon nanofibers?322 nm in diameter?with a large specific surface area(161.281m²g^-1).Acid red 1?AR1?,Cu Co@CNF,and PMS was used as the model pollutant,the catalyst,and the oxidant,respectively to study the catalytic activity of the catalyst.The results showed that 50 mg L^-1AR1 could be removed by more than 99.0% by Cu Co@CNF within 10 min.And the TOC removal rate of AR1 can reach 55.5% within 20 min,indicating that CuCo@CNF-PMS system has a high mineralization efficiency.In addition,the saturation magnetization of Cu Co@CNF is close to 26.5 emu g^-1,indicating that it has good magnetic properties and excellent recycling performance.In the absence of catalyst activity regeneration,the removal efficiency of AR1 can still reach 98.1% after 7 cycles,indicating its excellent reuse performance.The degradation mechanism of AR1 was preliminarily elucided by the free radical capture experiment and the characterization of the element composition and electron configuration on the catalyst surface by XPS.The results showed that the active groups of azo dyes in the process of catalytic degradation were mainly reactive oxygen species(SO₄^·-,^·OH and ¹O₂).