Wiralestari, Weytha Dinda (2026) Studi Kinetika, Isoterm, dan Termodinamika Adsorpsi pada Biodekolorisasi Metil Oranye oleh Bacillus subtilis Terimobilisasi Matriks Sodium Alginat/Polivinil Alkohol/Karbon Aktif. Other thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Penggunaan pewarna sintetis secara masif, seperti metil oranye (MO), oleh industri telah memicu pecemaran air yang dapat mengancam ekosistem perairan dan kesehatan manusia. Tingginya stabilitas struktur menyebabkan MO sulit untuk didegradasi secara alami. Oleh karena itu, penelitian ini mengusulkan pendekatan biologis alternatif dengan memanfaatkan bakteri Bacillus subtilis terimobilisasi matriks beads sodium alginat/polivinil alkohol dengan karbon aktif (SA/PVA/karbon aktif). Karakterisasi karbon aktif dengan XRD mengindikasikan kemampuannya sebagai material adsorben. Kinerja biodekolorisasi dievaluasi melalui parameter fisikokimia, meliputi studi kinetika, isoterm, dan termodinamika adsorpsi. Variasi yang digunakan mencakup waktu kontak (1–300 menit), konsentrasi MO (25–500 mg/L), dan suhu (30–45°C) untuk mengetahui kapasitas dan mekanisme adsorpsi. Konsentrasi MO sebelum dan sesudah dekolorisasi diukur menggunakan spektrofotometer UV-Vis. Hasil penelitian menunjukkan bahwa kinetika adsorpsi mengikuti model orde dua semu dengan waktu kesetimbangan 240 menit, mengindikasikan bahwa adsorpsi bergantung pada jumlah situs aktif yang tersedia. Isoterm adsorpsi mengikuti model Langmuir dengan nilai kapasitas maksimum adsorpsi sebesar 0,335 mg/g, menunjukkan terjadinya adsorpsi monolayer pada permukaan homogen. Analisis termodinamika adsorpsi menunjukkan nilai perubahan energi bebas Gibbs (ΔG) negatif yang menandakan reaksi berlangsung spontan, entalpi (ΔH) positif menunjukkan sifat endotermik, serta entropi ΔS) positif mengindikasikan peningkatan ketidakteraturan saat proses adsorpsi. Analisis FTIR dan SEM mengonfirmasi interaksi gugus fungsi yang berperan terhadap dekolorisasi serta morfologi beads yang menunjukkan komposisi yang mendukung keberhasilan imobilisasi bakteri terhadap dekolorisasi. Secara keseluruhan, matriks SA/PVA/karbon aktif terbukti melindungi B. subtilis dan meningkatkan kinerja dekolorisasi secara sinergis, sehingga menjadikannya material adsorben yang potensial untuk dioptimasi lebih lanjut dalam pengolahan limbah pewarna.
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The massive use of synthetic dyes, such as methyl orange (MO), by industries has triggered water pollution that can threaten aquatic ecosystems and human health. Its high structural stability makes MO difficult to degrade naturally. Therefore, this study proposes an alternative biological approach utilizing Bacillus subtilis bacteria immobilized in sodium alginate/polyvinyl alcohol beads matrix with activated carbon (SA/PVA/activated carbon). Characterization of the activated carbon using XRD indicates its capability as an adsorbent material. Biodecolorization performance was evaluated through physicochemical parameters, including kinetic, isotherm, and thermodynamic adsorption studies. The variations used included contact time (1–300 minutes), MO concentration (25–500 mg/L), and temperature (30–45 °C) to determine the adsorption capacity and mechanism. MO concentrations before and after decolorization were measured using a UV-Vis spectrophotometer. The results showed that the kinetic adsorption followed a pseudo-second-order model with an equilibrium time of 240 minutes, indicating that adsorption depends on the number of available active sites. The isotherm adsorption followed the Langmuir model with a maximum adsorption capacity of 0,335 mg/g, indicating the occurrence of monolayer adsorption on a homogeneous surface. Thermodynamic adsorption analysis showed a negative Gibbs free energy change, indicating a spontaneous reaction; a positive enthalpy, indicating an endothermic nature; and a positive entropy, indicating an increase in randomness during the adsorption process. FTIR and SEM analyses confirmed the functional group interactions responsible for decolorization, as well as the bead morphology showing a composition that supports the successful immobilization of bacteria for decolorization. Overall, the SA/PVA/activated carbon matrix was proven to protect B. subtilis and synergistically enhance decolorization performance, making it a potential adsorbent material for further optimization in dye wastewater treatment.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | Bacillus subtilis, Biodekolorisasi, Isoterm, Kinetika, Metil Oranye, Termodinamika, Bacillus subtilis, Biodecolorization, Isoterm, Kinetic, Methyl Orange, Thermodynamic |
| Subjects: | Q Science > QD Chemistry > QD251.2 Chemistry, Organic. Biochemistry |
| Divisions: | Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47201-(S1) Undergraduate Thesis |
| Depositing User: | Weytha Dinda Wiralestari |
| Date Deposited: | 29 Jul 2026 02:41 |
| Last Modified: | 29 Jul 2026 02:41 |
| URI: | http://repository.its.ac.id/id/eprint/139214 |
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