CHARACTERIZATION OF SORBENT PRODUCED THROUGH IMMOBILIZATION OF HUMIC ACID ON CHITOSAN USING GLUTARALDEHYDE AS CROSS-LINKING AGENT AND Pb(II) ION AS ACTIVE SITE PROTECTOR

Uripto Trisno Santoso (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Lambung Mangkurat University, Jl. A. Yani Km 36 Banjarbaru, Kalimantan Selatan 70714)
Sri Juari Santosa (Department of Chemistry, Faculty of Mathematics and Natural Sciences,Universitas Gadjah Mada, Jl. Sekip Utara, Pos Box: BLS 21, Yogyakarta 55281)
Dwi Siswanta (Department of Chemistry, Faculty of Mathematics and Natural Sciences,Universitas Gadjah Mada, Jl. Sekip Utara, Pos Box: BLS 21, Yogyakarta 55281)
Bambang Rusdiarso (Department of Chemistry, Faculty of Mathematics and Natural Sciences,Universitas Gadjah Mada, Jl. Sekip Utara, Pos Box: BLS 21, Yogyakarta 55281)
Shogo Shimazu (Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho,Inage-ku, Chiba-shi, Chiba, 263-8522)

Indonesian Journal of Chemistry
Vol 10, No 3 (2010)

Sorbent produced through immobilization of humic acid (HA) on chitosan using glutaraldehyde as cross-linking agent and Pb(II) ions as active site protector has been characterized. Active sorption site of HA was protected by reacting HA with Pb(II) ion, and the protected-HA was then activated by glutaraldehyde, crosslinked onto chitosan, and deprotected by 0.1 M disodium ethylenediamine tetra-acetic acid (Na2EDTA). The protected-crosslinking method enhanced the content of immobilized-HA and its chemical stability. Based on the FTIR spectra, crosslinking of HA on chitosan probably occurred through a chemical reaction. The sorption capacity of sorbent still remains unchanged after the second regeneration, but some of HA start to be soluble. The latter shows that cross-linking reaction between HA and chitosan is through formation an unstable product. The effectiveness of sorbent regeneration can also be identified by the XRD pattern.