PENGARUH PENAMBAHAN TRIPOLYFOSFAT PADA KITOSAN BEADS UNTUK ADSORPSI METHYL ORANGE

Abstract

Modifikasi kitosan dilakukan dalam rangka meningkatkan daya adsorpsi kitosan. Penambahan tripolyfosfat (TPP) dapat mempengaruhi kinerja kitosan untuk mengadsorpsi methyl orange. Penambahan cross-linker epiklorohidrin (ECH) bertujuan untuk meningkatkan stabilitas kimianya dalam kondisi asam serta membentuk pori kitosan beads lebih besar. Penelitian ini bertujuan untuk mengetahui konsentrasi dan lama perendaman TPP optimum pada adsorpsi methyl orange oleh kitosan. Konsentrasi TPP (1%, 5%, 10% dan 15% b/v) dan lama perendaman  dalam TPP (1, 3, 6, 12, dan 24 jam) divariasi untuk mendapatkan jumlah methyl orange teradsorpsi optimum. Evaluasi kondisi optimum dilakukan dengan mengadsorpsi methyl orange dengan metode batch. Kondisi optimum diperoleh pada adsorpsi kitosan dengan konsentrasi TPP 10% dan lama perendaman selama 12 jam dengan jumlah methyl orange yang teradsorpsi mencapai 12,5 ± 0,744 mg/g. TPP berpengaruh pada pembentukan pori dan kekakuan kitosan beads. Karakterisasi SEM menunjukkan bahwa pori kitosan beads tergolong makropori dan pori partikulat. Spektra FTIR menunjukkan bahwa TPP  telah mampu melindungi gugus NH₂ dari kitosan tetapi masih tertinggal di dalam kitosan beads. Mekanisme adsorpsi lebih bersifat fisik karena spektra FTIR kitosan beads setelah adsorpsi tidak jauh berbeda dengan kitosan beads sebelum adsorpsi yang ditandai oleh serapan pada 2362 cm^-1 yang menunjukkan terdapatnya methyl orange di dalam kitosan beads.

Chitosan modifications performed in order to increase the adsorption capacity of chitosan. Addition tripolyfosfat (TPP) can affect the chitosan performance to adsorb methyl orange. The addition of cross-linker epichlorohydrin (ECH) aims to improve chemical stability in acidic conditions and to form larger pores of chitosan beads. This study aims to determine the concentration and immersion time TPP optimum in adsorption of methyl orange by chitosan. TPP concentrations (1%, 5%, 10% and 15% w / v) and immersion time in TPP (1, 3, 6, 12, and 24 hours) were varied to obtain the optimum amount of adsorbed methyl orange. Evaluation of the optimum condition is done by adsorption of methyl orange by the batch method. The optimum conditions obtained in the adsorption of chitosan with TPP concentration of 10% and a immersion time for 12 hours with the amount of adsorbed methyl orange reached 12.5 ± 0.744 mg/g. TPP effect on pore formation and stiffness chitosan beads. SEM characterization showed that the porous of chitosan beads classified as macropore and particulate pore. FTIR spectra showed that the TPP has been able to protect the NH₂ group of chitosan but still lagging behind in the chitosan beads. Adsorption mechanism is more physical interaction because of the FTIR spectra of chitosan beads after adsorption is not much different from the chitosan beads before adsorption by absorption at 2362 cm^-1 which indicate the presence of methyl orange in the chitosan beads.