Synthesis of Zeolite as a Textile Dye Waste Adsorbent from Rice Husk Ash Using Microwave Heating Method

The zeolite was synthesized from rice husk ash with high silica content using the microwave heating method. In the pre-treatment step, the silica content of rice husk ash was extracted by HCl at various concentrations. Zeolite was synthesized by the reaction of rice husk ash, the aqueous solution of NaOH and Al₂O₃ in the flask reactor, and was treated by microwave heating at various power from 100-200 W. The crystalline phase and the characteristic structure of the product were analyzed by XRD and SEM analysis. Moreover, the surface area of the product was analyzed by BET analysis. The result shows that with 2 M HCl as an acid treatment in the pre-treatment step, the high surface area of the zeolite was obtained, i.e., 266.7 m²/g. The adsorption efficiency of the product was analyzed using methylene blue, methyl orange, and methyl red as the textile dye waste. The result shows that the adsorption efficiency of the product on the methylene blue, methyl orange, and methyl red was 94.2%, 93.89%, and 94.7%, respectively.