| The pollutants in wastewater,such as organic pollutants,antibiotics and heavy metal ions,ect.,are directly let out into the surface water or seep into the groundwater environment,seriously polluting the water environment,leading to the deterioration of water environmental quality and endangering the health of human life and diet.And the waste water can erode the soil,seriously affect the soil production performance,hinder the healthy development of China’s agriculture.Therefore,it is urgent to develop new adsorption materials to make up for the deficiency of traditional materials and achieve more convenient,rapid and efficient treatment of pollutants in water.In this paper,based on the iron-based metal-organic framework material—MIL-88 A nanoparticles,three kinds of porous composite microparticles of metal-organic framework material with different structures were designed and constructed by using microfluidic technology,homogeneous emulsification technology and dopamine silver plating technology,namely porous structure MIL-88A/polymer microparticles,hierarchical porous structure MIL-88A/polymer microparticles,and bubble-driven MIL-88A/polymer microparticles.And the removal ability of Rhodamine B by three kinds of composite microparticles was compared and studied.The main contents are as follows:（1）Rod-like MIL-88 A nanoparticles with high specific surface area were successfully prepared by hydrothermal synthesis.At the same time,the removal ability of activated carbon and MIL-88 A on pollutants was comparatively studied by using the organic dye Rhodamine B as the pollutant model.It was found that,due to the heterogeneous Fenton-like reaction,MIL-88 A exhibited good catalytic degradation performance for Rhodamine B in hydrogen peroxide solution,and the removal efficiency was 65.66 %,which was much higher than that of activated carbon（23.84 %）.（2）Porous MIL-88A/polymer microparticles loaded with rod-like MIL-88 A nanoparticles with good monodispersity and uniform size were successfully prepared by microfluidic technology.The microparticles have nano-scale porous structure,and both the surface and the interior of the microparticles are loaded with MIL-88 A.The porous MIL-88 A /polymer microparticles coupled with the mass transfer effect of the porous structure and the catalytic degradation of MIL-88 A showed a good removal ability for Rhodamine B.（3）Hierarchical porous MIL-88A/polymer microparticles loaded with rod-like MIL-88 A nanoparticles with good monodispersity and uniform size were successfully prepared by homogeneous emulsification technology and microfluidic technology.The microparticles show interconnected hierarchical porous structures with micro-scale and nano-scale porous structures,and both the surface and the interior of the microparticles are loaded with MIL-88 A.The hierarchical porous MIL-88A/polymer microparticles combined the mass transfer enhancement of the hierarchical porous structure with the catalytic degradation of MIL-88 A nanoparticles,showing a better removal ability for Rhodamine B.（4）The hierarchical porous structure MIL-88A/polymer microparticles were selectively coated with polydopamine and loaded Ag nanoparticles by using dopamine silver plating technology to prepare bubble-driven MIL-88A/polymer microparticles.The Ag nanoparticles on the microparticles can decompose hydrogen peroxide to generate bubbles,provide power for the self-driving of the microparticles,and enhance mass transfer.In addition,compared with the hierarchical porous MIL-88A/polymer microparticles（91.49 %）,the bubble-driven MIL-88A/polymer microparticles couple the mass transfer enhancement of the bubble propelling motion and the catalytic degradation performance of MIL-88 A,which further enhances the removal ability of pollutants,and its removal rate is as high as 99.23 %.Based on the above studies,the porous composite microparticles of metal-organic frameworks can be coupled with the mass transfer of the porous structure,the catalytic degradation performance of MIL-88 A nanoparticles,and the propulsion performance of bubbles.And the microparticles show the removal capability of high stability,high adsorption capacity and high-efficiency for pollutants in water,providing new materials for environmental safety governance. |
