Fabrication And Adsorption Properties Of Metal-organic Framework Composites

With the growth of population and the rapid development of social economy and science and technology,environmental problems have become increasingly prominent,and environmental pollution such as the atmosphere,water,solid waste,and soil has become more and more serious.The rational use of water resources,the protection and improvement of the quality of the water environment,and the provision of safe drinking water are the top priorities.The purification of water quality and the removal of heavy metal pollution from water bodies have attracted widespread attention from today's scientists.In this paper,the metal organic skeleton,ZIF-67 and the HKUST-1 is loaded onto the filter paper and the organic glass,and the preparation of seven green and green materials is used to absorb the heavy metals cadmium and lead in the water,which provides experimental basis,theoretical basis and method to remove heavy metals from the water.First,the property,source,migration and transformation process of heavy metal pollutants are described.the main method to remove heavy metals in water were introduced.Second,the development and application of metal-organic frameworks,and their major synthetic methods were presented.Finally,it outlines the research content,significance and innovation of this topic.A novel composite material ZIF-67@FP was prepared by immobilizing the metal-organic framework ZIF-67 on the surface of the filter paper with the filter paper as the carrier.The ZIF-67@FP before and after adsorption was characterized by infrared,X-ray diffraction,scanning electron microscopy and elemental analysis.Adsorption of heavy metal cadmium in water using the prepared ZIF-67@FP composite was performed.When the initial concentration of Cd(II)was 50 mg/L,the adsorption time was 6 h,the adsorption temperature was 30°C,the shaking rate was 160 rpm,the addition amount was 80 mg,the adsorption amount of ZIF-67@FP for Cd(II)was 15.59 mg/g.The time,initial concentration,adsorbent dosage,p H,ionic strength and other factors on the adsorption were explored.By calculating the adsorption kinetic parameters,it was found that the pseudo-secondary adsorption kinetics was more suitable for the adsorption process of Cd(II)by ZIF-67@FP.By studying the adsorption isotherm parameters,it was found that ZIF-67@FP is closer to the Langmuir adsorption isotherm model.After thiourea was used to elute and resorb ZIF-67@FP,the adsorption capacity of ZIF-67@FP composite could still reach 12.55 mg/g after 5 cycles.The HKUST-1@FP composite material was prepared by immobilizing the metal organic framework HKUST-1 on the surface of the filter paper using the mechanism that the hydroxyl functional groups on the surface of the filter paper reacted with the metal.The materials before and after adsorption were characterized by means of infrared,X-ray diffraction,scanning electron microscopy and elemental analysis.Exploring the removal of heavy metal lead in water by the composite HKUST-1@FP,when the initial concentration of Pb(II)is 200mg/L,the adsorption time is 5h,the adsorption temperature is 30°C,the shaking rate is 160 rpm,and HKUST-1@FP dosage is 200 mg,the adsorption capacity was 47.54 mg/g.The effects of time,initial concentration,adsorbent dosage,pH,ionic strength and other factors on the adsorption were investigated.By calculating the kinetic parameters of adsorption,it was found that the pseudo-secondary adsorption kinetics was more suitable for HKUST-1@FP adsorption of Cd(II).Adsorption process.By calculating the adsorption isotherm parameters,it was found that HKUST-1@FP is closer to the Langmuir adsorption isotherm model.After the HKUST-1@FP composite material was eluted with thiourea,its adsorption capacity could still reach 42.7 mg/g after 5 cycles.Because the organic glass can be dissolved in the nature of the organic solvent,ZIF-67/PMMA-1,ZIF-67/PMMA-2,HKUST-1 were prepared by adding different proportions of different metal organic frameworks to the solution containing the PMMA.HKUST-1/PMMA-1,HKUST-1/PMMA-2,HKUST-1/PMMA-4 composites.It was characterized by infrared,X-ray diffraction,scanning electron microscopy and other methods.By adsorbing cadmium and lead,respectively,it was found that the adsorption property of ZIF-67/PMMA-2 and HKUST-1/PMMA-4 was better.After elution the adsorbed composites by thiourea,the adsorptive property of ZIF-67/PMMA-2 and HKUST-1/PMMA-4 were still 7.75 mg/g and 35.64 mg/g after 5 cycles.