Antibiotic Removal From Water By Visible Light Coupled With FeOOH Systems Activate Peroxysulphate And Hydrogen Peroxide

In recent years,advanced oxidation processes（AOPs）based on peroxysulphate（PDS）and hydrogen peroxide（H₂O₂）are gradually becoming one of the leading methods for the treatment of antibiotics in water.To further enhance the activation efficiency of PDS and H₂O₂in AOPs,this study selected iron hydroxyoxide（FeOOH）as the catalyst and combined the photocatalytic and oxidant activation systems to construct a visible light-assisted PDS and H₂O₂activation technology,which enhanced the process performance through the synergistic effect between visible light,catalyst and oxidant.In this paper,the synthesis of FeOOH/BiOI composites and the addition of hydroxylamine（HA）as a co-catalyst were specifically investigated to improve their performance,and their activation effects on PDS and H₂O₂under visible light synergy were explored to construct an efficient and green AOPs system,which provides optional methods for the treatment of refractory pollutants.The main work of this thesis is as follows:（1）FeOOH material was prepared by water bath method and characterized by XRD,SEM,FT-IR and UV-vis-DRS methods.Based on the successful synthesis of FeOOH material,the photocatalytic system was coupled with the oxidant activation systems,the visible light coupled with FeOOH activate PDS system and the visible light coupled with FeOOH activate H₂O₂system were established,which exhibited good tetracycline（TC）removal rates of 89.3%and 91.1%,respectively.The removal of TC by different systems were systematically investigated,and the reusability performance and influencing factors of the catalysts were explored.The results showed that the removal of TC was mainly attributed to the chemical catalysis of FeOOH,and the irradiation of visible light accelerated the separation of photogenerated electrons and holes,which promoted the production of active substances for the degradation of TC in the reaction process.Combined with the results of the capture experiments,the active substances present in the systems were identified,hydroxyl radicals（·OH）,sulfate radicals（SO₄^-·）and superoxide radicals（·O₂^-）were the main reactive substances in the PDS system,and·OH and h⁺were the main reactive substances in the H₂O₂system.Based on this result,the mechanism was analyzed.Finally,the stability of the materials and the removal of TC in different water matrices were investigated.（2）The FeOOH/BiOI composite was synthesized by precipitation method and characterized by XRD,SEM,XPS and EDS to demonstrate the successful composite between the two monomers.On this basis,the visible light synergistic FeOOH/BiOI activate PDS system and the visible light synergistic FeOOH/BiOI activate H₂O₂system were established,and the norfloxacin（NOR）removal efficiency of the systems were significantly improved compared with the original FeOOH or BiOI monomers,the NOR removal rates of PDS system and H₂O₂system were 66.9%and 57.3%.UV-vis-DRS result demonstrated that the synthesis of the composite led to an improved visible light responsiveness,which further promoted the separation of photogenerated electrons from holes.Thus,more active substances were produced in the system,which was beneficial to the degradation of NOR.The influencing factors such as composite ratio,pH and oxidant dosage were investigated by single-factor experiments.The results of the capture experiments showed that·OH,·O₂^-and h⁺were the main reactive substances in the PDS and H₂O₂systems,and the reaction mechanism was analyzed accordingly.Finally,the stability of the composites and the removal of NOR in different water matrices were investigated.（3）Hydroxylamine（HA）-enhanced visible-light coupled with FeOOH activate PDS system and HA-enhanced visible-light coupled with FeOOH activate H₂O₂system were established for NOR removal from water,and the results showed that the addition of certain amount of HA could significantly improve the NOR removal effect,the NOR removal rates of PDS system and H₂O₂system were 56.3%and 89.7%.The factors influencing the reaction process were also investigated.pH,HA dosage and oxidant dosage all had an effect on the removal effect.The results of the capture experiments showed that·OH,SO₄^-·and·O₂^-were the main active substances of the PDS system,and h⁺and·OH were the main active substances of the H₂O₂system.and a possible reaction mechanism was proposed based on this result.Finally,the stability of the catalyst in the presence of HA was investigated,and the removal of NOR from different water matrices was measured.In summary,the visible-light coupled with FeOOH,visible-light coupled with FeOOH/BiOI and HA-enhanced visible-light synergisti coupled with FeOOH activate PDS and H₂O₂systems were established,this enriches the visible-light-assisted non-homogeneous AOPs and provide a variety of alternative techniques for the efficient degradation and removal of organic pollutants in water.