Electronic Theses and Dissertation

Adanya peningkatan produksi tekstil di Indoneisa tiap tahunnya menyebabkan meningkatnya limbah zat warna, salah satunya limbah methylene blue. Methyelene blue bersifat non-biodegradable sehingga tidak dapat diurai dengan proses biologi konvensional dan memiliki tingkat toksisitasnya yang tinggi sehingga dapat merusak sistem tubuh manusia dan lingkungan. Berbagai metode telah dikembangkan untuk mereduksi limbah methylene blue, salah satunya dengan proses adsorpsi. Pada penelitian ini menggunakan adsorben yang berasal dari ampas nilam dan diaktivasi menggunakan asam klorida (HCl). Penelitian diawali dengan mempirolisis ampas nilam pada suhu 380oC selama 1,5 jam. Adsorben dilakukan juga aktivasi kimia dengan larutan HCl pada konsentrasi 0,3, 0,5, dan 0,7 M. Karakterisasi adsorben dilakukan berdasarkan uji kadar air, kadar abu, dan daya serap iodin sesuai SNI 06-3730-1995 serta menggunakan FTIR, XRD, SEM, dan BET. Hasil yang diperoleh pada seluruh sampel adsorben ampas nilam memenuhi syarat standar mutu yang ditetapkan oleh SNI 06-3730-1995 sehingga dapat dengan optimal digunakan sebagai adsorben untuk menyerap methylene blue. Selain itu, hasil analisa FTIR menunjukkan bahwa terdapat gugus fungsi C-O, C=O, C=C, dan C-H sebagai gugus aktif untuk menyerap methylene blue. Hasil analisa XRD menunjukkan bahwa adsorben ampas nilam setelah aktivasi memiliki struktrur mikrokristalin yang sangat tidak teratur dan bersifat amorf. Hasil analisa SEM menunjukkan bahwa pori terbesar terdapat pada adsorben ampas nilam setelah pirolisis dan aktivasi kimia sebesar 14,699 μm. Hasil analisa BET menunjukkan bahwa luas permukaan dan diameter pori terbesar terdapat pada adsorben ampas nilam setelah pirolisis dan aktivasi kimia sebesar 57,083 m2/g dan 1274,06 nm. Adsorpsi ini dilakukan secara batch dengan waktu kontak selama 150 menit sehingga ditemukan performa adsorpsi, isotherm, kinetika, dan termodinamika adsorpsi. Kapasitas dan efisiensi adsorpsi tertinggi mencapai 9,1029 mg/g dan 96,369%. Model isotherm dan kinetika yang menggambarkan proses adsorpsi adalah isotherm Temkin dan pseudo first order. Termodinamika adsorpsi menunjukkan bahwa proses yang terjadi secara endotermik, peningkatan ketidakteraturan, spontan, dan physisorption.

Kata kunci: Ampas nilam, pirolisis, asam klorida, adsorpsi, methyelene blue

Increasing textile production will also produce increased dye waste, one of which is methylene blue waste. Methylene blue is non-biodegradable so it cannot be broken down by conventional biological processes and has a high level of toxicity so it can damage the human body system and the environment. Various methods have been developed to reduce methylene blue waste, one of which is the adsorption process. In this research, adsorption was used using an adsorbent derived from patchouli dregs and activated using hydrochloric acid (HCl). The research began by pyrolyzing patchouli dregs at a temperature of 380oC for 1.5 hours. Next, chemical activation was carried out with HCl solution at concentrations of 0.3, 0.5, and 0.7 M. Characterization of the adsorbent was carried out based on tests for water content, ash content, and iodine absorption capacity according to SNI 06-3730-1995 and using FTIR, XRD, SEM, and BET. The results obtained on all samples of patchouli dregs adsorbent met the quality standard requirements set by SNI 06-3730-1995 so that it could be optimally used as an adsorbent to absorb methylene blue. Apart from that, the results of FTIR analysis show that there are functional groups O-H, C=O, C=C, as active groups to absorb methylene blue. The results of XRD analysis showed that the patchouli dregs adsorbent after activation had a very irregular microcrystalline structure and was amorphous. The SEM analysis results show that the largest pores found in the patchouli dregs adsorbent after pyrolysis and chemical activation were 14,699 μm. The results of BET analysis show that the largest surface area and pore diameter are found in the patchouli dregs adsorbent after pyrolysis and chemical activation of 57.083 m2/g and 1274.06 nm. This adsorption was carried out in batches with a contact time of 150 minutes so that the adsorption performance, isotherm, kinetics and thermodynamics of adsorption were found. The highest adsorption capacity and efficiency reached 9.1029 mg/g and 96.369%. The isotherm and kinetic models that describe the adsorption process are the Temkin isotherm and pseudo first order. Adsorption thermodynamics shows that the process occurs endothermically, increasing disorder, spontaneously, and physisorption. Keywords: Patchouli dregs, pyrolysis, hydrochloric acid, adsorption, methylene blue