SINTESIS ZEOLIT A DARI ABU LAYANG BATUBARA DAN MODIFIKASINYA MENGGUNAKAN HDTMAB SEBAGAI ADSORBEN MULTIFUNGSI; SYNTHESIS OF ZEOLITE A FROM COAL FLY ASH AND ITS MODIFICATION USING HDTMAB AS MULTIFUNCTIONAL ADSORBENT

Jumaeri, Sri Juari Santosa

2015 | Tesis | FMIPA

Synthesis of zeolite A from coal fly ash and its modification using hexadeciltrimethylammonium bromide (HDTMAB) have been conducted. The reaction products were tested for their activity as a multifunctional adsorbent for species of anionic and cationic of dye and heavy metal, and for nonionic species of organic molecule. The synthesis of zeolite A from fly ash was carried out by using a modified alkaline fusion method followed by hydrothermal process. Structure and properties of the synthesized zeolite were characterized using XRD, FTIR, SEM-EDX, cation exchange capacity and surface area. The surface modification was performed using cationic surfactant HDTMAB twice as much as the cation exchange capacity of the zeolite A resulted. Examination of activity as adsorbent was performed by batch method in the variation of pH, contact time and initial concentration of adsorbate. The used adsorbate include Congo Red anionic dye, Crystal Violet cationic dye, metal ions Cr(III), CrO4 2-, and para-nitrophenol as nonionic species in aqueous solution. The use of the hydrothermal method through stage of modified alkaline fusion can produce selective zeolite A. The product of zeolite A exhibited characteristics similar to zeolite A standard in terms of the crystal structure, functional group and surface morphology. HDTMAB surfactant-modified zeolite A did not only adsorb anionic species of Congo Red and CrO4 2-, but also adsorbed cationic species of Crystal Violet and metallic ions of Cr(III), which is not exhibited by the zeolite A without modification. At the optimum conditions, the adsorption of surfactant-modified zeolite A for Congo Red, CrO4 2-, Crystal Violet and Cr(III) respectively reached 83.89, 55.00, 53.84, and 94.34%, while for paranitrophenol at 93 %. This is indicates that the surfactant-modified zeolite A can be used as a multifunctional adsorbent. The adsorption of surfactant modified zeolite A for Congo Red and Crystal Violet followed the Langmuir isotherm models and pseudo-second order kinetics models. For adsorption of CrO4 2- and Cr(III) by surfactant-modified zeolite A followed the Freundlich isotherm models, and pseudo-first-order kinetics for CrO4 2- and pseudo-second order for Cr(III). For the PNP adsorption on zeolite A and surfactant-modified zeolite A, it is fitted both Freundlich isotherm and the pseudo-second-order kinetics models.

Kata Kunci : fly ash; synthesis of zeolite A; HDTMAB modification; and multifunctional adsorbent