You are here: Home :: Area NEM :: Chemistry :: Physical chemistry

Rashid Ahmad, Muhammad Mufazzal Saeed, Akbar Ali, Jamshed Hussain Zaidi

Removal of Tm(III) ions from aqueous solution using PAN-incorporated sol–gel matrices

Keywords: 1-(2-pyridylazo)-2-naphthol (PAN), Radiotracer techniques, Sol-gel Matrices, Sorption isotherms, Tm(III) ions

The sorption of Tm(III) ions from aqueous solutions by 1-(2-pyridylazo)-2-naphthol (PAN) incorporated sol–gel matrices have been studied extensively using radiotracer and batch techniques. Maximum accumulation (∼98%) of Tm(III) ions (2.55×10^-5 M) onto solid surface is achieved from pH 7 buffer solution in 30 min using 50 mg of PAN incorporated sol–gel matrices. The sorption data follow Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms. The Langmuir constants Q=123.6±3.6 μmol g^-1 and b=(19.2±2.1)×10⁴ dm³ mol^-1 have been computed. Freundlich constants l/n=0.56±0.04 and C_m=45.4 ±6.5 mmol g^-1 have been estimated. Sorption capacity 1.13 ±0.001 mmol g^-1, β=-0.0035 ±0.0001 kJ² mol^-2 and energy 11.95 ±0.2 kJ mol^-1 have been evaluated using D–R isotherm. The variation of sorption with temperature yields ΔH= 31.7 ± 0.8 kJ mol^-1, ΔS=128.5 ± 3 J mol^-1 K^-1 and ΔG=-6.5 ± 0.1 kJ mol^-1 at 298 K reflecting the endothermic and spontaneous nature of sorption. Divalent Pb(II), Ba(II) and Mg(II) and monovalent chloride and K(I) increase the sorption while oxalate, citrate, disulfite and tartrate reduce the sorption significantly.

Radiochimica Acta, Oldenbourg Wissenschaftsverlag

Print ISSN: 0033-8230
Volume: 95, 08/2007
Pages: 451 - 457

Show full article (external site)

Show all available items of this journal

 

Area NEM