Studies On Degradation Of Organic Pollutants In Water By Modified Magnetic Iron-based Nanomaterials

Generally,it is difficult to effectively degrade organic pollutants by ordinary biological treatment methods.The rise and application of nanomaterials has provided a wide range of possibilities for the degradation of organic pollutants,among which magnetic iron-based nanomaterials have stood out due to various advantages.In this paper,two magnetic iron-based nanomaterials were prepared.After optimization of the materials,they were applied to the degradation of the dyes RhB and ciprofloxacin,respectively.The main research contents and conclusions are as follows:?1?A novel Fe₃O₄ impregnated graphene oxide?Fe₃O₄@GO?-activated persulfate system?Fe₃O₄@GO+K₂S₂O₈?was synthesized by following one-pot synthesis and was tested on water containing dye pollutants.In the presence of the PS-activated system,the degradation efficiency of Rhodamine B?RhB?was significantly increased to a level of?95%compared with that of Fe₃O₄??25%?.The influences of different operational parameters,including solution pH,persulfate dosage,and RhB concentration,were systemically evaluated.This system maintained its catalytic activity and durability with a negligible amount of iron leached during successive recirculation experiments.The degradation intermediates were further identified through reactive oxygen species?ROS?studies,where surface-bound SO₄^·–was found to be dominant radical for RhB degradation.Moreover,the degradation mechanism of RhB in the Fe₃O₄@GO+K₂S₂O₈ system was discussed.Finally,the results indicate that the persulfate-activated Fe₃O₄@GO catalyst provided an effective pathway for the degradation of dye pollutants in real wastewater treatment.?2?The sulfide-modified nanoscale zerovalent iron?S-NZVI?was synthesized by a two-step method,and the organic compound ciprofloxacin?CIP?was used as the target pollutant.The results showed that the S-NZVI?0.5 g/L?could achieve a 92%removal rate of 10 mg/L CIP,which was 1.6 times higher than the unmodified NZVI?59.1%?.Through comparative experiments,it was found that CIP was removed by S-NZVI through a combination of adsorption,reduction,and Fenton reaction.The pre-reaction period was mainly adsorption effect,and after 10 min,it was mainly reduction and Fenton reaction.The initial pH of the solution will significantly affect the removal rate of CIP by S-NZVI,among which the best is near neutral,and the alkaline effect is the worst.XRD,TEM,and XPS results show that sulfide-modified can not only greatly improve the reactivity of nanoscale zerovalent iron,but also reduce agglomeration and side reactions with water and oxygen,thereby improving the electron utilization rate of Fe⁰.This study provides a feasible solution for the effective removal of CIP.