Synthesis Of Thiodiglycolamide And Study On The Extraction Behavior Of Heavy Metals

Water resources have played an important role in both development of human lifeactivities and social economy. At present, our country is facing two big problems, one is thewater pollution can not be effectively curbed and the other is the continued deterioration of thewater environment, and these two problems form a huge contradiction with the requirementsof improved living-environment, healthy and safety water and the high level of the drinkingwater quality. But with the development of the modern industrial production, the wastewatercontain heavy metal increasing annually to the environment, it made the river reservoirpolluted, and made the ecological system more frail. Due to the heavy metal pollution causedgreat threat to human health as well as other creatures, and even endanger the life,so it is aproblem we must solve in urgent to improve the water resources which polluted by heavymetal.Solvent extraction plays an important role in treating waste water of heavy metal pollution,it can separated and enriched the heavy metals and then recovery them. Design and synthesisof novel extractants and explor the extraction system are two parts of solvent extraction, theapplication has great significance.In this paper four kinds of extractants were designed and synthesized and the extractionbehavior were studied:(1) Four kinds of extractants: N, N, N’, N’-tetrabutyl-thiodiglycolamide (TBTDGA), N, N,N’, N’-tetraoctyl-thiodiglycolamide (TOTDGA), N, N, N’, N’-tetra(2-ethylhexyl)-thiodiglycolamide (T(2EH)TDGA), N,N’-dimethyl-N,N’-dioctyl-thiodiglycolamide (DBDOTDGA) weredesigned and synthesized, the products were analysed by infrared spectroscopy and1H NMRspectrum;(2)In hydrochloric acid system the extractants could extract cadmium (II) in addition toTBTDGA; the extraction distribution ratio was increased with the increasing of hydrochloricacid concentration; the extraction reaction was an exothermic process; according to theextraction equilibrium formula the extraction mechanism have been known and the molecularstructure of extraction compounds represent as CdCl2·DBDOTDGA, CdCl2·TOTDGA,CdCl2·2T(2EH)TDGA respectively; and the equilibrium constants and thermodynamic functions values have been calculatd;(3) The four kinds of extractants could extract cadmium (II) in ammonia system and thebest conduction was in weak alkaline condition; the extraction distribution ratio was discreasedwith the increasing of ammonia concentration; the extraction reaction was an exothermicprocess; according to the extraction equilibrium formula the extraction mechanism have beenknown and the molecular structure of extraction compounds represent asCd(NH3)3(NO3)2·DBDOTDGA, Cd(NH3)3(NO3)2·TOTDGA, Cd(NH3)3(NO3)2·TBTDGA,Cd(NH3)3(NO3)2·T(2EH)TDGA respectively; and the equilibrium constant and thermodynamicfunctions value have been calculated;(4) The four kinds of extractants could extraction lead (II) in hydrochloric acid system;the extraction distribution ratio was discreased with the increasing of hydrochloric acidconcentration; the extraction reaction was an exothermic process; according to the extractionequilibrium formula the extraction mechanism have been known and the molecular structure ofextraction compounds represent as PbCl2·TOTDGA, PbCl2·DBDOTDGA, PbCl2·TBTDGA,PbCl2·T(2EH)TDGA respectively; and the equilibrium constant and thermodynamic functionsvalue have been calculated.