Removal And Purification Of Phenols And Ceftiofur Sodium In The Environment By Two New Adsorbent Based On Ionic Liquid

Adsorption is a commonly-used method for removing environmental pollutants.It has many advantages such as simple operation,low cost and good adsorption effect,and is widely used in many fields such as separation,enrichment and solid phase extraction.Traditional adsorbents such as activated carbon,silica gel have broad-spectrum adsorption properties for substances in the environment,and the recycling cycle is not effective.However the high-risk pollutants in the environment need to be removed in a targeted manner,so it is a challenge to synthesize a new adsorbent that has a specific adsorption capacity and can be effectively recycled.Ionic liquid is an organic molten salt composed of anion and cation.Due to its advantages of non-oxidation,non-volatilization,strong solubility,strong thermal stability and structural design,it has attracted much attention in the fields of material synthesis and separation.In recent years,the new polymer materials synthesized by ionic liquids have the advantages of strong specific recognition ability,large adsorption capacity and good regeneration performance,which have become the hotspots of adsorbent materials research.In this paper,two ionic liquids（brominated 1-butyl-3-vinylimidazole and brominated1-allyl-3-vinylimidazole）were used as reaction monomers to synthesize two new adsorbent materials（the new ionic liquid polymer and ceftiofur sodium imprinted polymer）in green aqueous medium.;Two new adsorbent materials were characterized by various means;the adsorption performance of two new adsorbent materials was investigated by equilibrium adsorption experiments;The two new adsorbent materials were made into solid phase extraction microcolumns for the separation and removal of phenols and ceftiofur sodium from actual samples.The specific research contents are as follows:1.Two new adsorbent materials（the new ionic liquid polymer and ceftiofur sodium imprinted polymer）were synthesized in green aqueous medium by using 1-butyl-3-vinylimidazolium bromide and1-allyl-3-vinylimidazolium bromide;The microstructure,specific surface area,pore volume,molecular structure and thermal stability of the two new adsorbent materials were analyzed by scanning electron microscopy,specific surface area analysis,infrared spectrum scanning and comprehensive thermal analysis.2.The adsorption isotherm,adsorption kinetics,adsorption thermodynamics and selective adsorption properties of two new adsorbent materials at three temperatures（25°C,35°C,45°C）were investigated by equilibrium adsorption experiments.The results show that（1）The new ionic liquid polymer has strong specific recognition ability for 2,4-dichlorophenol（2,4-DCP）,bisphenol A（BPA）,2,4-dinitrophenol（2,4-DNP）and 2-naphthol（2-NP）,and the adsorption amount is 48.33.mg g^-1,40.38 mg g^-1,38.31 mg g^-1and 36.96 mg g^-1;The adsorption process of 2,4-dichlorophenol,2-naphthol and bisphenol A by new ionic liquid polymers is consistent with the Langmuir adsorption model,and the adsorption of 2,4-dinitrophenol accords with the Freundlich adsorption model;the adsorption of 2,4-dichlorophenol and bisphenol A by the new ionic liquid polymer is a spontaneous endothermic reaction,while the adsorption of2,4-dichlorophenol and bisphenol A is a spontaneous exothermic reaction.The adsorption kinetics results show that the adsorption process of 2,4-dichlorophenol,bisphenol A,2,4-dinitrophenol and 2-naphthol by the new ionic liquid polymer accords with the quasi-second-order kinetic model and the balance time is 15min,20 min,40 min and 25 min.（2）When four substances（ceftiofur sodium,ceftriaxone sodium,amoxicillin sodium,metronidazole）coexist,the adsorption capacity of ceftiofur sodium imprinted polymer adsorbent material(MIP_CTFS)on the template molecule（ceftiofur sodium）is the highest(2.98 mg g^-1).and the distribution coefficient is the highest(0.06 L g^-1);The adsorption of ceftiofur sodium by MIP_CTFS is in accordance with the Freundlich adsorption model,and the adsorption process is a spontaneous exothermic reaction;The adsorption kinetics results show that the equilibrium time of the adsorption of ceftiofur sodium by MIP_CTFS and NIP_CTFS is respectively 30 min and 10 min,and the adsorption amounts at this time is 5.24 mg g^-1 and 2.24 mg g^-1,respectively;The adsorption of ceftiofur sodium by MIP_CTFS and NIP_CTFSTFS conforms to the quasi-second-order kinetic model.3.Two new adsorbent materials were used in the dynamic column experiment and used under the optimal conditions for the separation and purification of phenols and ceftiofur sodium in actual samples.The results show that two new adsorbent materials（new ionic liquid polymer and ceftiofur sodium imprinted polymer）for four phenols（2,4-dinitrophenol,2-naphthol,bisphenol A and 2,4-dichlorophenol）and ceftiofur sodium have good selective separation and removal ability,and the recovery rate can reach more than 85%;After 30 regeneration cycles of the two adsorbents,the recovery rates of the four phenols and ceftiofur sodium were not significantly reduced,indicating that the two new adsorbent materials synthesized in this paper have a good ability to remove and purify trace phenolic pollutants and ceftiofur sodium in the environment.