| Based on a large number of related literatures at home and abroad,this paper selects nano-zero-valent iron(nZVI)as the research body,and uses multiple modification methods to modify the nano-zero-valent iron(nZVI)in multiple dimensions.Thirteen carbon dibasic acids(DC 13)and ciprofloxacin(CIP)were selected as the target pollutants.The performance of nZVI after multi-dimensional modification to remove non-degradable organic compounds was studied.Analyze the mechanism of the changes before and after the reaction and the process of removing pollutants,which are mainly divided into the following three aspects:1.Synthesis of bimetallic nZVI/Cu to remove DC 13 in water:nZVI/Cu bimetallic particles were synthesized by liquid phase reduction using sodium borohydride for the treatment of DC13 in simulated organic wastewater.The results show that the nZVI/Cu bimetallic composite has a mass ratio of 1:0.04,a loading of 0.6g/L,a reaction time of 12h,and an initial pH of 8,the best effect of removing DC 13,and the degradation of DC 13 can reach 90.%,LC-MS results show that DC 13 is degraded into small inorganic molecules by hydroxyl radicals(·OH)generated by zero-valent iron corrosion2.Under the condition of weak magnetic field(WMF),a combined system of polyvinylpyrrolidone(PVP)and nano-sized zero-valent iron(nZVI)and copper(Cu)bimetallic particles(PVP-nZVI/Cu)was designed.Ciprofloxacin(CIP)reduction further characterization of the surface morphology and physicochemical properties of the novel catalytic materials.In addition,the catalytic reactivity of PVP-nZVI/Cu was measured in the presence or absence of WMF.The experimental results show that the introduction of WMF can improve the catalytic performance of PVP-nZVI/Cu system,and the maximum CIP removal rate reaches 95.6%(120 min).Kinetic analysis indicated that the degradation of CIP was consistent with the pseudo first order kinetics.Finally,the degradation products of CIP after reaction with PVP-nZVI/Cu nanocomposites were determined by mass spectrometry(MS).Quantitative analysis of material adsorption and Fenton oxidation during CIP removal was also evaluated.As the removal process progressed,the effects of PVP-nZVI/Cu adsorption and Fenton oxidation changed dynamically.It was observed that the Fenton reaction gradually began to dominate the degradation process as the reaction progressed.3.Use green tea extract to synthesize nanoscale zero-valent iron(nZVI)and copper(Cu)bimetallic particles GT-nZVI/Cu for degradation of ciprofloxacin(CIP)under weak magnetic field(WMF)and study its Possibility of recovery:In this study,the surface morphology and physicochemical properties of the novel catalytic materials were characterized.GT-nZVI was found to be more stable and exhibits better oxidation resistance than nZVI synthesized by conventional chemical methods.In addition,the catalytic activity of GT-nZVI/Cu was measured with and without WMF.It can be seen from the experimental results that the addition of WMF significantly improves the performance of the GT-nZVI/Cu system.In addition,WMF has a certain effect even after being removed,which is called a remanence effect.The degradation products of CIP were analyzed by mass spectrometry(MS),and the contribution of GT-nZVI/Cu adsorption and Fenton reaction during CIP removal was further evaluated.Finally,green tea extract was used to try to regenerate GT-nZVI/Cu,where physical recovery(ultrasonic)was the main route,and as the number of regenerations increased,the CIP removal rate decreased... |
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