Development Of A New Type Of Highly Efficient Adsorbent For The Enrichment Of Rare Earth Ions And Preparation Of Cerium Phosphate Nanomaterials Via Ionic Liquid-Based Supported Membrane System

In view of the present situation of secondary resources recovery of rare earth and the influence of rare earth elements in water like industrial wastewater or contaminated water.In this paper,a new rare earth preconcentration method was studied,and its enrichment and adsorption properties were studied.In order to solve the problem of the traditional preparation method of rare earth phosphate,this paper presents a new system for preparing rare earth phosphate nanomaterials,and the experiment achieves the expected effect.In the first chapter,a DTPA cross-linked ?-cyclodextrin(DTPA-?-CD)absorbent were prepared and utilized to remove and preconcentrate rare earth elements(REEs)such as Pr(?),Nd(?),Eu(?),Tb(?),Yb(?)and Lu(?)from aqueous solutions.The?-cyclodextrins were linked by the multi-carboxyl groups of DTPA via esterification reactions.The DTPA also plays the role of coordination sites for biding REEs.FT-IR and elemental analysis are presented to verify the linkage of ?-CD.Batch tests of different ratios of DTPA to ?-CD were carried out to investigate the best ratio for obtaining REEs removal or preconcentration absorbents.Interestingly,while the ratio was 8:1,the prepared absorbents showed a pH sensitive absorbing property when biding REEs.The kinetic and thermodynamic data experiments were conducted to investigate the adsorbing property of DTPA-P-CD towards REEs by different models.The kinetic results were best described by the pseudo-second order kinetic model.The thermodynamic data fit well with the Freundlich equation,suggesting a chemical adsorption dominating the REEs adsorption.Moreover,the absorbent was used to preconcentrate REEs from pure and tap water,making it a promising absorbent for the preconcentration of REEs from aqueous solution.For the first time,our group has developed a novel,high-flux strategy for shape-controlled synthesis of rare earth nano-materials(CePO4)using ionic liquid(IL)-driven supported liquid membrane(HVHP,DUPAPORE(?))system in the second chapter of this paper.The system contains three phases including a supply phase of rare earth ions,a feed phase of phosphates,and ionic liquid-mediated supporting liquid membrane phase.The imidazolium IL-mediated supported liquid membrane is promising for nano-synthetic reaction of CePO4.The anion types of immersed imidazolium IL have a critical role in the formation rate of CePO4 nano-materials.Moreover,the adding SO42-anion or adjustment of pH in supply phase containing Ce(?)ions could control effectively the morphology of the CePO4 nano-materials.The result can be regarded as a good example,the IL:[C4mim)[Tf2N]-mediated support liquid membrane systems can be used to prepare nano-wire and nano-sphere structures of CePO4 with high efficiency and flux.Besides,the IL-mediated supported liquid membrane can be cycled many times by using the back flush activation method.