Diethylenetriaminepentaacetic Acid Impregnated Ceralite IR 400 for Transition Metal Complexation: Implication for Separation and Recovery

Abstract

The impregnation of diethylenetriaminepentaacetic acid (DTPA) onto an anionic strong base resin Ceralite IR 400 is described. Mixing DTPA solution with Ceralite IR 400 in water carried out the procedure. The maximum impregnation is 1.164 mmol of DTPA/g of Ceralite IR 400. The DTPA impregnated resin was used for transition metal‐DTPA complexation. The distribution coefficients (K_d) of 15 metal ions were determined in demineralized water, 0.05 M ammonium acetate solution and acetate buffers (pH=2, 4, and 6). On the basis of significant difference between distribution coefficients of metals M₁ and M₂ (K_dM1/K_dM2≥3), the quantitative separations were tried on the Pyrex glass column (30 cm long and 0.4 cm i.d.), packed with 1 g of DTPA‐Ceralite IR 400 resin. The separations achieved are: Cu(II)–Zn(II)–Ag(I), Mn(II)–Pt(IV)–Zr(IV), Ni(II)–Pt(IV), Ni(II)–Fe(III), Co(II)–Fe(III), Ni(II)–Zn(II), Cu(II)–Au(III) and Mo(VI)–Cr(VI). The break through curves were studied for ziroconium. By increasing the impregnated amount of DTPA from 0.100 to 1.164 mmol/g of Ceralite IR 400, column capacity increased from 106.69 to 1261.13 mmol Zr/l of DTPA‐resin. DTPA impregnated Ceralite IR 400 resin can be applied for the removal of zirconium(IV) from aqueous solutions (100 µg/l to 5 mg/l). Zirconium, preconcentrated on resin can be recovered quantitatively (97.2–99.8%) with 2 M HCl as eluting reagent. The proposed column technique is also successful for the removal and recovery of zirconium from synthetic seawater with almost the same efficiency.

Keywords:

• Column liquid chromatography
• DTPA‐impregnated Ceralite IR 400
• transition metal ions
• separation
• recovery