Adsorption Performance Of Imidazolium Poly(Ionic Liquid)s For Cr(Ⅵ)、Mo(Ⅵ)、W(Ⅵ) Isopolyacid Anions And Chloro-Mercury Complex Anions

Heavy metal pollution is an urgent problem in pollution prevention and control at present.Ionic liquids,as a new type of functional materials,are widely used in adsorption,catalysis,separation and purification.In this thesis,two imidazolium poly（ionic liquid）s were synthesized as an adsorbent,and its adsorption performance on the group VIB metal isopolyacid anions and chloro-mercury complex anions in water was studied.The adsorption conditions were optimized and the main mechanism of adsorption was speculated.The dynamic adsorption process of the adsorbent was discussed.The paper is mainly divided into four parts:In the introduction,the main physicochemical characteristics of VIB group metals and mercury and their wide application in the process of life and production are described.The main sources and forms of heavy metals such as chromium and mercury flowing into the ecological environment and their harm to human body and the environment are briefly introduced.The traditional methods of treating wastewater polluted by heavy metals such as VIB and mercury are reviewed.The application of ionic liquid and poly（ionic liquid）s in separation and purification was introduced.In the second part,two imidazolium poly（ionic liquid）s with styrene-4-vinylbenzyl chloride copolymer as the framework were synthesized.The adsorption conditions were optimized from time,temperature,dosage,interference ion and other factors by using two imidazolium poly（ionic liquid）s to adsorb VIB metal in water.The adsorbents before and after adsorption were characterized by IR and NMR.The results showed that the two imidazolium poly（ionic liquid）s could rapidly and efficiently enrich and recover the isopolyacid anions of Cr（VI）,Mo（VI）and W（VI）with metal content of 10 mg?L^-1 from the solution,and the adsorption efficiency was up to 98%.At the same time,the metal ions commonly found in the waste solution had little effect on the adsorption effect.The adsorbent and metal can be separated effectively with the corresponding eluent.Under the best conditions,the content of VIB metal in the solution can reach the national emission standard.In the third part,the imidazolium poly（ionic liquid）s were used to adsorb HgCl₄^2-in water,and the conditions such as temperature,time,concentration and interference ion were optimized.Two imidazoliumpoly（ionic liquid）s can rapidly and selectively enrich and recover 15 mg?L^-1 HgCl₄^2-from the solution.The elution performance of thiourea isexcellent,and the adsorption capacity of Hg was still high in the five cycles.The adsorbents were characterized by IR,NMR,XPS and EDS.The results show that HgCl₄^2-and imidazolium poly（ionic liquid）s have strong electrostatic attraction,while weak hydrogen bond,n-πand other supra-molecular interactions make the adsorption ability stronger and better.Single crystal was obtained by the reaction product of monomer room temperature ionic liquid and HgCl₄^2-.Under the optimum conditions,the mercury content in the solution was lower than the national emission standard.In the fourth part,the imidazolium poly（ionic liquid）s PSVB-C2ImCl was used for the dynamic adsorption experiment of HgCl₄^2-.The effects of column height,flow rate and interfering ions on dynamic adsorption were investigated,and the adsorption behavior was simulated by using the model.The results show that,compared with increasing the column height,decreasing the flow rate can improve the adsorption efficiency and utilization ratio of the poly（ionic liquid）s.The adsorption of mercury in simulated industrial wastewater is affected by the interference ions,but it still has a certain adsorption capacity,which lays a foundation for the industrial application of the new adsorbent.