ADSORPTION OF METHYLENE BLUE DYE USING RICE HUSK ASH BASED MESOPOROUS SILICA

• Main Author: Constantine, Adrian
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/85083
• Institution: Institut Teknologi Bandung

The use of rice husk ash (RHA) as an alternative precursor to tetraethyl orthosilicate (TEOS) was investigated for various characteristics related to the adsorption of methylene blue (MB) dye. Silica was extracted via thermal reflux (1 hour, 100°C) using 200 ml of 8% w/v NaOH solution with 12.5 grams of RHA, resulting in dissolved Na2SiO3, which was slowly added to 380 ml of 1.6M HCl solution along with surfactant P123 in varying amounts (5, 10, and 15 grams). After aging (24 hours, 40°C), drying (24 hours, 100°C), and calcination (5 hours, 600°C), white mesoporous silica powder was produced. Brunauer-Emmett-Teller (BET) characterization showed mesoporous properties with high specific surface areas (m2/g): 396.65, 414.32, and 422.97, and pore radii (nm): 3.39, 3.08, and 3.06. Fourier-Transformed Infrared Spectroscopy (FTIR) characterization indicated three siloxane group peaks and hydroxyl group peaks from silanol. Scanning Electron Microscopy (SEM) characterization revealed cubic and spherical particles covered with small aggregates, indicating micelle templating. The adsorption isotherm fit the Freundlich model with an average R2 = 0.8867. Adsorption kinetics matched the pseudo-second-order model with an average R2 = 0.945. The maximum MB adsorption capacities (mg/g) at an initial concentration of 300 ppm for 5, 10, and 15 grams of P123 were 59.782, 82.668, and 117.692, respectively