Study On Catalytic Performances Of Bioinspired Catalyst Based On Iron Phthalocyanine For Degradating Antibiotics

The bioinspired catalyst R-N-Fe was prepared by iron phthalocyanine（FePc）covalently immobilized on chloromethalated crosslinking polystyrene microsphere（R）simultaneously axial coordination with 4-aminopyridine（4-ampy）introduced by pre amination focusing on antibiotics wastewater treatment.R-N-Fe was fully characterized by ultraviolet-visible spectrometer,fourier transform infrared spectroscopy,Zeta potential measurements,scanning electron microscope images,nitrogen gas uptake and the functional group capacities,ensuring the successful synthesis of the material and the multidirectional control of relevant properties.Removal performances of oxytetracycline hydrochloride（OTCH）in R-N-Fe/H₂O₂system was investigated.Results showed that the skeleton loading could effectively guarantee the catalytic activity of FePc,while the pushing electrons function of 4-ampy through the coordination interaction between N and Fe not only improved the ability of catalyst to activate H₂O₂,weakening the influence of light and saving cost,but also accelerated the conversion of Fe（III）to Fe（II）,making sure the effective operation and stable circulation of the whole reaction.Hydroxyl radical（·OH）was proved to be the dominant active species in the system by tert-butyl alcohol quenching experiments and electron paramagnetic resonance（EPR）tests.A possible pathway for the operation pattern of R-N-Fe/H₂O₂ system was proposed.Subsequently,the effects of temperature,H₂O₂ concentration,R-N-Fe dosage,initial OTCH concentration and initial pH value on the removal of OTCH were investigated.The four ring molecular structure of OTCH could be validly destroyed which provided a relatively high mineralization degree and the OTCH removal could be described by second-order kinetics.Removal performances of tetracycline hydrochloride（TCH）in R-N-Fe/PMS（peroxymonosulfate,PMS）system was discussed.It was revealed that benefited from the unique electron-rich conjugated large ring structure of FePc and the electron donor effect of4-ampy,R-N-Fe showed a significant advantage in the activation of PMS.Meanwhile,EPR combined with three kinds of radical scavengers（ascorbic acid,methanol and tert-butyl alcohol）was employed to comfirm that·OH and sulfate radical（·SO₄^-）served as the main active species and·SO₄^-played a more critical role in TCH oxidation.Subsequently,the effects of temperature,PMS concentration,R-N-Fe dosage,coexisting Cl^-and initial pH on the removal of TCH were investigated.Limited to the inherent nature of·SO₄^-and the concentration of PMS,the removal of TOC by the R-N-Fe/PMS system waited for further enhancement.Finally,the catalytic mechanism of PMS over R-N-Fe was reasonably suggested.Through the introduction of response surface methodology（RSM）,a multifactor model for the removal of OTCH in the R-N-Fe/H₂O₂ system was established,and the multifactor response surface for OTCH degradation was obtained.The conditions of each factor were studied in a comprehensive way and the optimal operating conditions in the selected interval were determined:T=307.5K,[R-N-Fe]=0.75g/L,[H₂O₂]=0.06M,initial pH=5.3.Verification tests indicated that the difference between the actual value and the predicted value was small,illustrating the good predictability and accuracy of the model.The stability experiment showed that the catalytic performance of R-N-Fe just decreased slightly with the increase of reaction cycles and a relatively good stability could be maintained in the system.