Applied Research, The Separation Of Metal Ions In The Membrane Separation Technology

In recent years, environment scientists pay much attention to the environmenteffects of the heavy metal ions in industrial wastewater because some of metal ions cancause the heavy damages to the health of human and biological balance. Therefore, it isvery necessary to develop a new wastewater treating technique with high efficiency,saving energy and environment protection.The separation technique with liquid membrane containing a mobile carrier is anovel technique with simple, high efficiency and good selective, which has been widelyapplied to the separation and concentration of metal ions, removal of phenol fromwastewater, and biological application such as anificial Kidney. Howevef, the techniquemeet some limitations such as the structure defects and membrane carrier loss ofsupported liquid membranes, and the conflict between emulsion and de-emulsion ofemulsion membranes. Therefore, the bulk liquid membrane containingorganophosphorus acid was applied to the transfer investigations of copper(Ⅱ) andzinc(Ⅱ), and avoided effectively the problems above in this work. The experimentalresults are described as below:(1) The extraction behavior of copper(Ⅱ) and zinc(Ⅱ) from 1.0 mol dm(-3)ammonium sulfate solution into Naphtezol M containing bis (2-ethylhexyl )phosphinicacid has been studied as a function of pH and extractant concentration. The pH(1/2) valueswere determined to be 2.24 and 3.73 for Zinc(Ⅱ) and Copper(Ⅱ), respectively. The datehave been analyzed numerically to determine the stoichiometry of extracted specieswere found to be (ZnR2·2HR)2 and (ZnR2·6HR)2 for Zinc(Ⅱ) and (CuR2·2HR)2 and(cuR2· 6HR)2 for coPPer(Ⅱ), resPectively.(2) The transfer rate of coPPer(Ⅱ) and lead(Ⅱ) from aqueous feed sulfate solutionto inorganic acid strip soluton through a bulk liquid membrane consisting2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC-88A) as membran carrierand CHCl3 as membrane solvent, was studied, respectively. The influence of the pHvalues in external aqueous phase, PC-88A carrier concentrations, experimentaltemperatures and the concentrations of inorganic acid in internal aqueous, wasinvestigated. The half-transfer pH(1/2) values were determined under differentconcentrations of the carrier. The permeability coefficients and the values ofthermodynamics functions Δhθ and Δsθ of copper(Ⅱ) and lead(Ⅱ) through bulk liquidmembrane have been experimentally measured.