Electronic Theses and Dissertation

Penelitian ini bertujuan untuk menghilangkan zat warna metilen biru menggunakan selulosa dari alang-alang (Imperata cylindrica) termodifikasi glutamin. Selulosa berhasil diisolasi dari alang-alang yang dibuktikan dengan spektrum FTIR, dimana tidak ditemukan puncak serapan dari lignin dan hemiselulosa. Difraktogram XRD menunjukkan indeks kristalinitas selulosa meningkat setelah perlakuan kimia dan ultrasonikasi. Modifikasi selulosa dilakukan dengan variasi komposisi glutamin. Komposisi terbaik diperoleh dengan berat 0,2 gram glutamin. Penambahan glutamin pada selulosa menyebabkan interaksi kimia yang dibuktikan dengan spektrum FTIR, pengamatan SEM dan berkurangnya indeks kristalinitas selulosa-glutamin pada difraktorgram XRD. Kondisi adsorpsi optimum diperoleh pada pH 6 dengan waktu kontak 30 menit dengan kapasitas adsorpsi sebesar 7,003 mg/gram. Model kinetika reaksi adsorpsi mengikuti model kinetika pseudo orde 2 (PSO) dengan nilai R2 = 0.99842 dan k = 0.288632 mg.g-1 /menit. Nilai Qmaks dari persamaan Isoterm Langmuir diperoleh sebesar 33,003 mg/gram. Nilai termodinamika untuk ∆H, didapatkan sebesar 16,1705 Kjmol-1. Dari hasil penelitian ini dapat disimpulkan bahwa selulosa-glutamin berpotensi menjadi adsorben zat warna metilen biru.

Kata kunci: Selulosa Alang-alang (Imperata cylindrica), glutamin, adsorpsi, metilen biru.

This research aims to remove methylene blue dye using cellulose from reeds (Imperata cylindrica) modified with glutamine. Cellulose was successfully isolated from reeds as proven by the FTIR spectrum, where no absorption bands from lignin and hemicellulose were found. The XRD diffractogram showed that the crystallinity index of cellulose increased after chemical and ultrasonication treatment. Cellulose modification was carried out by varying the glutamine composition. The best composition was obtained with a weight of 0.2 grams of glutamine. The addition of glutamine to cellulose caused chemical interactions as evidenced by the FTIR spectrum, SEM observations and a decrease in the cellulose-glutamine crystallinity index in the XRD difractorgram. Optimum adsorption conditions were obtained at pH 6 with a contact time of 30 minutes with an adsorption capacity of 7.003 mg/gram. The kinetic model of the adsorption reaction follows the pseudo 2nd order (PSO) kinetic model with values of R2 = 0.99842 and k = 0.288632 mg.g-1 /min. The Qmax value from the Langmuir Isotherm equation was obtained at 33.003 mg/gram. The thermodynamic value for ∆H was obtained at 16.1705 Kjmol-1. From the results of this research can be concluded that cellulose-glutamine has the potential to be an adsorbent for methylene blue dye. Keywords: Reeds (Imperata cylindrica) cellulose, glutamine, adsorption, methylene blue.