MODIFIKASI KITOSAN MELALUI PROSES SWELLING DAN CROSSLINKING MENGGUNAKAN GLUTARALDEHIT SEBAGAI PENGADSORPSI LOGAM Cr (VI) PADA LIMBAH INDUSTRI BATIK MODIFICATION OF CHITOSAN BY SWELLING AND CROSSLINKING USING GLUTARALDEHYDE AS HEAVY METAL Cr (VI) ADSORBENT IN BATIK INDUSTRY WASTES

Abstract

Study on chitosan modification by swelling and crosslinking and its application as a selective adsorbent for heavy metals Cr (VI) in batik industry wastes was done. Swelling is intended to improve chitosan porosity, whereas crosslinking is to increase the resistance of chitosan against acid. Natural samples are generally acidic, thus limiting chitosan application as an adsorbent. Modification of chitosan by combining swelling and crosslinking is expected to increase its adsorption capacity in binding heavy metal ions in water. At first, chitosan was dissolved in 1% acetic acid, and swelling process was then conducted by spraying into 5% NaOH solution to form chitosan beads. Next chitosan beads were crosslinked using Glutaraldehyde (Glut) with various concentrations of 8, 10, 20, and 25%. The modified chitosan was later contacted with Cr (VI) to test its adsorption capacity with variation of pH and contact time. Finally, application of modified chitosan was done in batik industry wastes containing Cr (IV). Based on the results, chitosan-Glu 25% (v/v) was the optimum concentration of crosslingker to adsorb Cr (VI) ions. Modified chitosan has a solubility resistance to acids, even though a strong acid. Modification of chitosan improved also its adsorption capacity to Cr (VI) from 74% (pure chitosan) to 89% with contact time 30 min. and pH 3. On the application to the batik wastes, the modified chitosan were able to adsorb Cr (IV) up to the level of 5 ppm. Thus, the modified chitosan has a potential to be applied as an adsorbent of Cr (VI) in batik industry wastes. Keywords: Chitosan, Swelling, Crosslinking, Glutaraldehyde (Glut