Electronic Theses and Dissertation

Nadia Muthadilla. (2026). Adsorpsi p-Nitrofenol Menggunakan Silika dari Sekam Padi Terimpregnasi Fe–Mn: Optimasi, Isoterm, dan Kinetika Adsorpsi. [Skripsi. Universitas Syiah Kuala]. Dibawah bimbingan Dr. Ibnu Khaldun, M.Si. dan Drs. Rusman, M.Si.

p-Nitrofenol (PNP) merupakan senyawa fenolik yang bersifat toksik, persisten, dan banyak digunakan dalam industri pestisida, farmasi, serta zat warna sehingga berpotensi mencemari lingkungan perairan. Adsorpsi merupakan salah satu metode yang efektif untuk menghilangkan PNP karena memiliki efisiensi tinggi, sederhana, dan menggunakan adsorben yang dapat dikembangkan dari limbah biomassa, seperti silika sekam padi. Penelitian ini bertujuan untuk menentukan kondisi optimum, model isoterm, dan model kinetika adsorpsi p-nitrofenol menggunakan silika dari sekam padi terimpregnasi Fe–Mn. Adsorben disiapkan melalui proses kalsinasi, pemurnian dengan metode acid leaching menggunakan HCl 1 M, serta impregnasi menggunakan Fe(NO₃)₃·9H₂O 0,10 M dan KMnO₄ 1,00 M dengan perbandingan Fe:Mn:Si sebesar 1:4:25. Penentuan kondisi optimum dilakukan melalui variasi waktu kontak, pH, massa adsorben, dan konsentrasi awal p-nitrofenol. Hasil penelitian menunjukkan bahwa kondisi optimum adsorpsi diperoleh pada waktu kontak 90 menit, pH 5, massa adsorben 0,10 g, dan konsentrasi awal p-nitrofenol 200 mg/L dengan efisiensi adsorpsi sebesar 94,996%. Analisis isoterm menunjukkan bahwa proses adsorpsi mengikuti model Langmuir dengan nilai koefisien determinasi (R²) sebesar 0,9914, lebih tinggi dibandingkan model Freundlich dengan nilai R² sebesar 0,9182, yang mengindikasikan terjadinya adsorpsi lapisan tunggal (monolayer) pada permukaan adsorben yang homogen. Analisis kinetika menunjukkan bahwa proses adsorpsi mengikuti model pseudo orde dua dengan nilai koefisien determinasi (R²) sebesar 0,99.
Kata Kunci: Adsorpsi, p-nitrofenol, silika sekam padi, impregnasi Fe–Mn, isoterm, kinetika.

Nadia Muthadilla. (2026). Adsorption of p-Nitrophenol Using Rice Husk Silica Impregnated Fe–Mn: Optimization, Isotherm, and Kinetic Studies. [ Thesis. Syiah Kuala University]. Under the supervision of Dr. Ibnu Khaldun, M.Si. and Drs. Rusman, M.Si. p-Nitrophenol (PNP) is a toxic and persistent phenolic compound widely used in the pesticide, pharmaceutical, and dye industries, and its presence in aquatic environments poses a significant risk of environmental pollution. Adsorption is considered an effective method for PNP removal due to its high efficiency, simple operation, and the potential use of biomass-derived adsorbents, such as rice husk silica. This study aimed to determine the optimum adsorption conditions, adsorption isotherm, and adsorption kinetics of p-nitrophenol using Fe–Mn-impregnated rice husk silica. The adsorbent was prepared through rice husk calcination, purification by the acid leaching method using 1 M HCl, and impregnation with 0.10 M Fe(NO₃)₃·9H₂O and 1.00 M KMnO₄ at a Fe:Mn:Si ratio of 1:4:25. The optimum adsorption conditions were determined by varying the contact time, solution pH, adsorbent dosage, and initial p-nitrophenol concentration. The results showed that the optimum adsorption conditions were achieved at a contact time of 90 min, pH 5, an adsorbent dosage of 0.10 g, and an initial p-nitrophenol concentration of 200 mg/L, resulting in an adsorption efficiency of 94.996%. The adsorption equilibrium was best described by the Langmuir isotherm model with a coefficient of determination (R²) of 0.9914, which was higher than that of the Freundlich isotherm model (R² = 0.9182), indicating monolayer adsorption on a homogeneous adsorbent surface. Furthermore, the adsorption kinetics followed the pseudo-second-order model with a coefficient of determination (R²) of 0.99. Keywords: adsorption, p-nitrophenol, rice husk silica, Fe–Mn impregnation, isotherm, kinetics.