Research Of High Efficient Adsorbent Based On Metal Organic Framework Materials

In recent years, metal organic frameworks?MOFs?, as a new type of adsorbent, have attracted much attention because of its large specific surface area, topological structure and adjustable pore size. In this paper, dye, chromate and p-nitrophenol were selected as the target pollutants, a variety of metal organic frameworks were prepared to study the adsorption behavior. The main researches are concluded as following:?1? The MIL-101-Fe was synthesized and characterized by XRD,FTIR,SEM,EDX and Zeta potential. NH₂ -MIL-101-Fe was synthesized by amino functionalization of MIL-101-Fe. The optimal adsorption conditions of NH₂ -MIL-101-Fe for two kinds of typical dyes were explored. The results showed that the optimum dosage of NH₂ -MIL-101-Fe was 0.01 g, and the adsorption time was 2 h. The adsorption kinetics data fit the pseudo-second-order equation well. The adsorption of AO7 on NH₂ -MIL-101-Fe was in accordance with the Langmuir and Freundlich model, while the adsorption of RhB was consistent with the Freundlich model. The adsorption capacity of NH₂ -MIL-101-Fe on the AO7 was better than that of the RhB, and the adsorption capacity of the two dyes were both good, which indicated that the MOFs had great potential in the field of dye adsorption.?2? Fe₃O₄ @NH₂ -MIL-101-Fe was synthesized by coprecipitation method. MIL-101-Fe was characterized by XRD,FTIR and TEM. The results showed that NH₂ -MIL-101-Fe was successfully coated on Fe₃O₄ , and successfully synthesized a core-shell structure Fe₃O₄ @NH₂ -MIL-101-Fe. The removal of chromate by Fe₃O₄ @NH₂ -MIL-101-Fe was deeply studied. The results showed that the optimum dosage of Fe₃O₄ @NH₂ -MIL-101-Fe was 0.08 g, the optimum solution pH was 5.67. The adsorption kinetics data fit the pseudo-second-order equation well. The adsorption isotherm onto Fe₃O₄ @NH₂ -MIL-101-Fe agreed well to the Freundlich adsorption isotherm. Fe₃O₄ @NH₂ -MIL-101-Fe possessed a high selective adsorption capacity to chromate by exploring coexisting ions. The adsorbents with adsorbed chromate can be separated quickly under magnetic field after adsorption.?3? XRD, FTIR and SEM were used to characterize the synthesized ZIF-8 material, and the results showed that the ZIF-8 material was successfully synthesized. The removal of p-nitrophenol?PNP? by ZIF-8 was deeply studied. The results showed that the optimum dosage of ZIF-8 was 0.02 g, the adsorption time was 30 min and the optimum solution pH was 6.50. The adsorption kinetics data fit the pseudo-second-order equation well. The adsorption isotherm onto ZIF-8 agreed well to the Freundlich adsorption isotherm. ZIF-8 possessed a high selective adsorption capacity to PNP by exploring coexisting molecules. ZIF-8 showed excellent regeneration and reusability, and can be reused for the removal of PNP by exploring adsorption-desorption cycles, which indicated that the metal organic framework materials have a broad prospect in the removal of PNP.