Removal Of Refractory Organic Pollutants From Water By Activated Rersulfate With ZIF-8 Or ZIF-67 Derived Catalysts

Environmental pollution caused by the massive use of antibiotics is becoming more and more serious.Advanced oxidation process（AOPs）is a common strategy to remove refractory pollutants.It is necessary to design heterogeneous catalysts that can efficiently activate persulfate to oxidize organic pollutants.In this paper,a series of ZIFs derived composite catalysts were prepared by solvothermal and calcination with ZIFs as precursors and metal ions doped.The structure and composition of the composite catalyst were characterized,and the efficiency and mechanism of activated persulfate removal of refractory antibiotics in water were investigated.The main research contents are summarized as follows:（1）Ni²⁺doped ZIF-8 was synthesized by solvothermal method and calcined at900°C in Ar atmosphere.The degradation of tetracycline（TC）by activated persulfate（PDS）was studied.The results show that the Ni Nx species can adsorb PDS,accept electrons and activate PDS to produce·O₂^-,and the ~1O₂ species can oxidize TC.In addition,ninx-regulated electron transfer and·O₂^-generated by dissolved oxygen in the system also participate in TC degradation reaction.The obtained catalyst has excellent stability and anti-environmental disturbance ability.（2）Carbon coated Co Mn₂O₄/Mn₃O₄（C-Co Mn O）composite catalyst was prepared by calcination of Mn²⁺doped ZIF-67.The degradation of ciprofloxacin（CIP）by activation of PMS was studied.The results show that 0.1 g/L C-2Co Mn O can activate PMS and degrade CIP effectively,and the total organic carbon（TOC）removal rate of the system is 81.33%after 60 min.The effects of Co/Mn mole ratio,calcination temperature,PMS concentration,solution p H and coexisting ions on CIP degradation were discussed.The results show that C-Co Mn O catalyst has good cycling performance and wide p H stability.·O₂^-,SO₄^·-and?HO radicals,~1O₂and surface complexes all participate in the CIP degradation process.Elemental analysis and theoretical calculation show that Co/Mn collaboration is more likely to adsorb and activate PMS,and the doped carbon simultaneously activates PMS through electron transfer.（3）ZIF-67 was used as precursor and Mn²⁺was synthesized by vulcanization-calcination of carbon-doped Co₃S₄/Co SO₄/Mn O（C-CSOM）composite catalyst.The degradation of levofloxacin（LVF）by activated PMS was investigated.The experiment showed that TOC removal rate was 83.62%after 45 min.·O₂^-and ~1O₂ are the main reactive oxygen groups,and high-valence species can also degrade LVF by electron transfer.The possible degradation paths of LVF were given.The obtained catalyst has excellent stability and anti-environmental disturbance ability.