AMINO AND MERCAPTO-SILICA HYBRID FOR Cd(II) ADSORPTION IN AQUEOUS SOLUTION

Buhani Buhani (Department of Chemistry, Faculty of Mathematic and Natural Sciences, Lampung University)
Narsito Narsito (Department of Chemistry, Faculty of Mathematic and Natural Sciences, Gadjah Mada University, Sekip Utara Yogyakarta 55281)
Nuryono Nuryono (Department of Chemistry, Faculty of Mathematic and Natural Sciences, Gadjah Mada University, Sekip Utara Yogyakarta 55281)
Eko Sri Kunarti (Department of Chemistry, Faculty of Mathematic and Natural Sciences, Gadjah Mada University, Sekip Utara Yogyakarta 55281)

Indonesian Journal of Chemistry
Vol 9, No 2 (2009)

Modification of silica gel with 3-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane through sol-gel technique producing amino-silica hybrid (HAS) and mercapto-silica hybrid (HMS), respectively, has been carried out using tetraethylorthosilicate (TEOS) as silica source. The adsorbents were characterized using infrared spectroscopy (IR), and X-ray energy dispersion spectroscopy (EDX). Adsorption of Cd(II) individually as well as its binary mixture with Ni(II), Cu(II), and Zn(II) in solution was performed in a batch system. Adsorption capacities of Cd(II) ion on adsorbent of silica gel (SG), HAS, and HMS are 86.7, 256.4 and 319.5 μmol/g with the adsorption energies are 24.60, 22.61 and 23.15 kJ/mol, respectively. Selectivity coefficient (α) of Cd(II) ion toward combination of Cd(II)/Ni(II), Cd(II)/Cu(II), and Cd(II)/Zn(II) ions on HAS adsorbent is relatively smaller than those on HMS adsorbent which has α > 1.