Sintesis dan Karakterisasi Komposit Kitosan–Silika melalui Metode Sol–Gel dari Ampas Tebu untuk Adsorpsi Ion Fe(III)

Abstract

Sugarcane bagasse is a waste material produced by sugar mills that can be utilized as an adsorbent due to its silica content. This study analyzes the characteristics of silica derived from sugarcane bagasse combined with chitosan through the sol–gel process and evaluates its application in the adsorption of Fe(III) heavy metal ions. The independent variable examined was the pH of the Fe(III) ion solution (2, 3, 4, 5, and 6), while the particle sizes of chitosan and silica were kept constant with a weight ratio of 1:10. Characterization analyses included FTIR, SEM-EDX, XRF, and AAS. XRF analysis of the silica extracted from sugarcane bagasse showed SiO₂ as the major component, accounting for 56.7%. The FTIR spectra revealed the presence of siloxane (Si–O–Si) and silanol (Si–OH) functional groups. SEM-EDX characterization confirmed that the chitosan–silica composite exhibited an uneven morphology, with silica particles distributed irregularly across the chitosan surface and containing 44.59% Si. The synthesized silica–chitosan composite demonstrates potential applicability as an adsorbent for Fe(III) heavy metal ions in aqueous solutions, achieving a maximum removal efficiency of 63.97% at pH 5.