SINTESIS ZEOLIT A DARI ABU DASAR BATUBARA DAN APLIKASINYA UNTUK ADSORPSI KOBALT (II)

Rr. Rochma Dwiningsih, Dr. rer. nat. Nurul Hidayat A., M.Si.

2011 | Tesis | S2 Ilmu Kimia

Telah dilakukan penelitian sintesis zeolit A dari abu dasar batubara PLTU Paiton Jawa Timur dan aplikasinya untuk adsorpsi kobalt(II). Sintesis zeolit A dilakukan dengan menggunakan kombinasi metode peleburan dengan NaOH dan perlakuan hidrotermal dengan memakai microwave. Hidrotermal dilakukan pada suhu 100 °C dan waktu 3 jam. Abu dasar dan zeolit A hasil sintesis dikarakterisasi dengan Fourier Transform Infrared (FTIR), XRD, Scanning Electron Microscopy (SEM) dan Gas Sorption Analyzer (GSA) dengan metode BET. Kajian adsorpsi meliputi parameter pengaruh pH, kinetika adsorpsi dan adsorpsi isotermal terhadap Co(II). Jumlah Co(II) yang teradsorpsi dianalisis dengan Atomic Absorption Spectrometry ( AAS). Hasil analisis dengan AAS menunjukkan bahwa abu dasar PLTU Paiton mengandung silika dan alumina yang merupakan bahan dasar dalam sintesis zeolit A. Karakterisasi dengan FTIR dan XRD menunjukkan bahwa pe leburan abu dasar dengan NaOH menghasilkan silika dan alumina amorf. Kondisi optimum adsorpsi 10 mL Co(II) oleh 40 mg abu dasar dan 40 mg zeolit A dicapai pada pH 7. Waktu adsorpsi 10 mL Co(II) untuk abu dasar dan zeolit A mulai konstan pada menit ke 30. Kinetika adsorpsi 10 mL Co(II) oleh 40 mg abu dasar dan 40 mg zeolit A lebih mengikuti kinetika orde satu model Santosa dkk. dibandingkan kinetika orde satu model Langmuir-Heinshelwood. Adsorpsi 10 mL ion Co(II) meningkat sampai 150 ppm untuk 40 mg zeolit A dan 60 ppm untuk 40 mg abu dasar. Adsorpsi 10 mL ion Co(II) oleh 40 mg zeolit A berlangsung secara kimia dan mengikuti adsorpsi isotermal model Langmuir dengan kapasitas adsorpsi, tetapan kesetimbangan (K) dan energi adsorpsi berturut-turut 5,19 x 10-4mol/g; 1,85 x 104mol-1L dan 24,59 kJ/mol. Adsorpsi 10 mL ion Co(II) oleh 40 mg abu dasar berlangsung secara fisika dan mengikuti adsorpsi isotermal model Freundlich dengan kapasitas adorpsi 0,04 mol/g dan tetapan kesetimbangan sebesar 1,24 mol-1L. Hasil penelitian ini menunjukkan bahwa zeolit A dapat disintesis dari abu dasar dan adsorpsi 10 mL ion Co(II) oleh 40 mg zeolit A lebih tinggi dari 40 mg abu dasar.

It was conducted study on synthesis of zeolite A from coal bottom ash in PLTU Paiton East Java and its application to the cobalt(II) adsorption. Synthesis of zeolite A was conducted by the combination of melting method of NaOH and its hydrothermal treatment using microwave. Hydrothermal treatment was conducted at the temperature of 100 degree C for 3 hours. The coal bottom ash and the synthetic zeolite A was characterized by FTIR, XRD, SEM and GSA using the method of BET. The adsorping study involved the influenced parameter of pH, kinetic adsorption and its isothermal adsorption of Co(II). The number of adsorpted Co(II) was analyzed using AAS. The analytical result using AAS showed that the coal bottom ash of PLTU Paiton contained silica and alumina that were the raw products synthesis of zeolite A. The characterization using FTIR and XRD showed that the melting process of coal bottom ash of NaOH produced the silicate and alumina amorf. The optimal condition of adsorption 10 mL Co(II) by 40 mg coal bottom ash and 40 mg zeolite A were reached at pH 7. The adsorption 10 mL Co(II) time for coal bottom ash of zeolite A was started to be stable at the 30 minute. The kinetical adsorption 10 mL Co(II) by 40 mg coal bottom ash and 40 mg zeolite A tended to follow the kinetical order of one model of Santoso et al, compared by the kinetical order of one model of Langmuir-Heinshelwood. The adsorption of 10 mL Co(II) increased to 150 ppm for the 40 mg zeolite A and 60 ppm for the 40 mg coal bottom ash. The adsorption of 10 mL Co(II) by 40 mg zeolite A was processed chemically and followed the isothermal adsorption model of Langmuir with the adsorption capacity, the equilibrium constant (K) and the adsorption energy were 5.19 x 10-4mol/g, 1.85 x 104mol-1L and 24.59 kJ/mol, respectively. The adsorption of 10 mL Co(II) by 40 mg coal bottom ash was processed physically and followed the isothermal adsorption model of Freundlich with the adsorption capacity and the equilibrium constant (K) were 0.04 mol/g and 1.24 mol-1L, respectively . The study results showed that the zeolite A could be synthesized from the coal bottom ash and the adsorption of 10 mL Co(II) by 40 mg zeolite A was higher than that was reached by the 40 mg coal bottom ash.

Kata Kunci : abu dasar, sintesis zeolit A, hidrotermal dengan microwave, kobalt