SYNTHESIS OF ZEOLITE A FROM COAL FLY ASH FOR REMOVAL OF COPPER IN AQUEOUS SOLUTION

• Main Author: Paramitha, Tifa
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/32954
• Institution: Institut Teknologi Bandung

Coal is an abundant source of fossil energy in Indonesia. Combustion of coal generally creates large quantity of coal fly ash as by-product. Coal fly ash disposed into landfill can cause environmental problems. Coal fly ash contain silica dan alumina. These components are the basic components in the formation of zeolite. The utilization of coal fly ash to zeolite is one of potential alternatives to eliminate the problem regarding the disposal of huge quantities of coal fly ash. Zeolite are aluminosilicates with three dimensional framework of [AlO4]4- and [SiO4]5- that are tetrahedrally connected to each other based on corner-sharing oxygen atoms. Zeolite A is zeolite that has high specific surface area and cation exchange capacity, so it is appropriate in heavy metals removal. The general purpose of this study is to obtain an appropriate conditions for converting coal fly ash into zeolite A. Furthermore, zeolite A was evaluated the removal performance of copper ions. Prior to use as raw material in synthesis of zeolite A, pretreatment of coal fly ash using hydrochloric acid solution was conducted to reduce iron and calcium content. The method used in the synthesized zeolite A is alkali fusion followed by hydrothermal process. XRD results showed the zeolite products were mainly similar to the crystal structure of zeolite A and it was found that optimum conditions to synthesize zeolite A were Si/Al molar ratio of 0.75; hydrothermal time of 1 hour; and water/coal fly ash ratio of 15 ml/g. The optimum conditions also could be indicated from high cation exchange capacity of approximately 5,14 meq/g and specific surface area of 37,121 m2/g. By batch method, relative pure zeolite A without hydroxysodalite was tested for its performance in removal Cu2+ ion in artificial solution. The result showed that zeolite A has removal capacity of Cu2+ ion is 76,49 mg/g. The removal data based on time were well fitted by the pseudo-second order kinetics model.