Syntheses Of Novel Chelating Resins And Their Application In Analysis Of Heavy Metals

The pollution of heavy metal ions(HMI)has already become serious problems that influence the survival of human being and other creatures.So the determination and analysis of trace heavy metal elements have very important significance to protecting people's health and strengthening people's constitution. And it is necessary to separate and concentrate before using the conventional instruments to analyze.It will have wide application prospect and research value in detection,analysis,resources recovery and reclamation to find a good and cheap adsorbent,which are both environmental friendly and can adsorb HMI effectively.In this thesis,five kinds of novel chelating resins that function as adsorption and separation from ten ligand were prepared.The structures were characterized by element analysis and FTIR.The properties of the chelating adsorption and the mechanism for several metal ions were studied.The simulated application test was used to screen out resins with excellent property which are applied to the separation,detection and analysis of HMI in water.1.New types of chelating resins were synthesized by cholromethylated polystyrene reacted with nitrogen-containing and sulfur-containing compounds of linear and heterocycle.The influence of synthesis conditions such as reaction solvents,temperatures,molar ratio and time on the reactions were studied.The structures and patterns are characterized by element analysis and FTIR.2.The adsorption properties of five resins for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)were systematically investigated by means of static and dynamic method,the adsorption mechanism was also discussed.The experimental results showed that: (1)The resins had powerful adsorption capacities for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)in HAc-NaAc medium at 298K.The statically saturated adsorption capacity of resins as follows:3-AT-R resin for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)were 382.5,157.6, 24.80 mg/g,TETA-R resin for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)were 332.6,189.1,137.4 mg/g,ADMP-R resin for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)were 101.8,180.9,51.06 mg/g, TSC-R resin for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)were 619.5,227.3,152.3 mg/g,ATZL-R resin for Hg(Ⅱ),Cd(Ⅱ),Pb(Ⅱ)were 263.7,154.6,28.61 mg/g,respectively. 0.5～3.0 mol/L HCl and 0.1%thiourea in 0.5mol/L HCl were tested for the recovery of heavy metals loaded in the resins adsorption operation,with elution percentage of 100%.(2)The adsorption isotherms approximately fitted the Langmuir equation within the range of experimental concentrations.The adsorption dynamics of five resins for three HMI indicated that adsorption fitted the Boyd G.E.equation and was controlled by the liquid film diffusion.The resins for HMI had strong ability of anti-jamming to Na~+,K~+ within certain concentration.(3)From the study of dynamic adsorption,the dynamic saturated adsorption Capacity of resins as follows:TSC-R,TETA-R,3-AT-R resin for Hg(Ⅱ)were 587.1 mg/g,360.3 mg/g,374.8 mg/g,TSC-R,TETA-R,ADMP-R resin for Cd(Ⅱ)were 5237.2 mg/g,215.3 mg/g,207.9 mg/g,TSC-R,TETA-R resin for Pb(Ⅱ)were 143.4 mg/g,139.0 mg/g,respectively.Hg(Ⅱ)adsorbed on TSC-R resin could be eluted by 0.1%thiourea in 0.5mol/L HCl and the elution percentage was up to 91.85%,others could be completely eluted.The HMI concentration of first 25mL desorption solution was approximately or over 50%. So it can be used as high concentration solution or recovery of heavy metals.(4) The adsorption mechanism of resins for HMI was also discussed.The research on mechanism showed that N or S atom on functional group of resins combined with HMI formed coordinate bond. 3.The adsorption and desorption properties of resins for model and real water samples including single and mixed heavy metals were investigated.The experimental results showed that:(1)From the study of resins for single heavy metal,it could be found out that the adsorption capacities of resins for HMI were slightly reduced under the seawater condition,that may because other component of seawater could decrease the adsorption capacity of HMI.(2)The dynamic adsorption curves of 3-AT-R resin for Hg(Ⅱ),TETA-R resin for Cd(Ⅱ),TSC-R resin for Pb(Ⅱ)were investigated,and the dynamic saturated adsorption capacity were 325.5 mg/g,197.8 mg/g,156.0 mg/g respectively.The HMI adsorbed on the resins could be completely eluted with corresponding eluant.(3) From the study of resins for mixed heavy metals of Cd(Ⅱ),Pb(Ⅱ),Cu(Ⅱ),it was demonstrated that the adsorption capacity of resins for HMI was different within the range of experimental condition because of the competitive adsorption.The recovery of three heavy metals was over 90%.The adsorption dynamics of resins for three HMI indicated that the adsorption rate was considerably high.As a whole,the adsorbability of five resins for Cu(Ⅱ)was much stronger than Pb(Ⅱ). So they could be used for separation and concentration of Cu(Ⅱ)from waste water which containing Cu(Ⅱ)and Pb(Ⅱ),and purification of water or sea water containing Cu(Ⅱ).