Electronic Theses and Dissertation

Retta Dela. (2025). Adsorpsi Methylene Blue pada Air Limbah Menggunakan Adsorben Nanopartikel Magnetik Fe-Mn.

Peningkatan penggunaan zat warna sintetis dalam berbagai aktivitas industri, khususnya industri tekstil, telah menyebabkan akumulasi limbah berbahaya yang berpotensi mencemari lingkungan perairan. Penelitian ini bertujuan untuk mengevaluasi kemampuan adsorben magnetik Fe-Mn dalam mengadsorpsi zat warna, khususnya Methylene Blue, sebagai solusi terhadap permasalahan pencemaran tersebut. Adsorben magnetik Fe-Mn disintesis melalui metode kopresipitasi dengan menggunakan prekursor FeCl3.6H2O, FeSO4.7H2O, dan MnCl2.4H2O. Hasil sintesis berupa padatan berwarna hitam kemudian dikarakterisasi menggunakan Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), dan X-Ray Diffraction (XRD). Spektrum FTIR menunjukkan keberadaan gugus O-H, Fe–O, dan Mn–O yang berperan sebagai situs aktif dalam proses adsorpsi. Citra SEM menunjukkan permukaan berpori dengan struktur hierarki dan ukuran partikel pada kisaran sub-mikro dan mikro. Difraktogram XRD mengidentifikasi fasa kristalin Fe3O4 dan MnFe2O4 dengan ukuran kristal rata-rata 27,7 nm. Uji adsorpsi dilakukan dengan memvariasikan waktu kontak, pH larutan, massa adsorben, dan konsentrasi awal Methylene Blue. Kondisi optimum adsorpsi diperoleh pada waktu kontak 50 menit, pH 6, massa adsorben 0,1 g, dan konsentrasi awal 150 mg/L. Efisiensi adsorpsi mencapai 97,98% dengan kapasitas adsorpsi (Qe) sebesar 15,069 mg/g. Model isoterm yang sesuai dengan data eksperimen model Hill-Deboer dengan nilai koefisien korelasi (R²) sebesar 0,9049, yang mengindikasikan adanya interaksi lateral antar molekul adsorbat. Hasil penelitian ini menunjukkan bahwa adsorben magnetik Fe-Mn memiliki potensi yang tinggi sebagai material ramah lingkungan untuk penanganan limbah zat warna di lingkungan perairan.

Kata kunci: Adsorben Magnetik, Methylene Blue, Fe-Mn, Kopresipitasi, Isoterm Hill-Deboer

Retta Dela. (2025). Adsorption of Methylene Blue in Wastewater Using Fe-Mn Magnetic Nanoparticle Adsorbent. The increasing use of synthetic dyes in various industrial activities, particularly in the textile industry, has led to the accumulation of hazardous waste that potentially contaminates aquatic environments. This study aims to evaluate the adsorption capability of magnetic Fe-Mn adsorbents in removing dyes, specifically Methylene Blue, as a solution to this pollution issue. The magnetic Fe-Mn adsorbent was synthesized via the coprecipitation method using precursors FeCl3.6H2O, FeSO4.7H2O, and MnCl2.4H2O. The resulting black solid was characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The FTIR spectra confirmed the presence of O-H, Fe-O, and Mn-O functional groups, which act as active adsorption sites. SEM images revealed a porous surface with hierarchical structures and particle sizes in the submicron to micrometer range. XRD diffractograms identified the crystalline phases of Fe3O4 and MnFe2O4, with an average crystallite size of 27.7 nm. Adsorption tests were conducted by varying contact time, solution pH, adsorbent mass, and initial Methylene Blue concentration. Optimal adsorption conditions were obtained at 50 minutes contact time, pH 6, 0.1 g of adsorbent, and an initial concentration of 150 mg/L. The adsorption efficiency reached 97.98% with an adsorption capacity (Qe) of 15.069 mg/g. The experimental data best fit the Hill–Deboer isotherm model, with a correlation coefficient (R2) of 0.9049, indicating the presence of lateral interactions between adsorbate molecules. These findings demonstrate that the Fe-Mn magnetic adsorbent has strong potential as an environmentally friendly material for addressing dye pollution in aquatic systems. Keywords: Magnetic Adsorbent, Methylene Blue, Fe-Mn, Coprecipitation Method, Hill-Deboer Isotherm