Characterization of Na-P1 zeolite synthesized from pumice as low-cost materials and its ability for methylene blue adsorption

Recently, many researchers have been applied zeolitic materials for dye wastewater treatment by adsorption method because of more practical and economical without requiring a lot of solvents. However, the presence of natural zeolite is limited and only available in a specific area. In this research, pumice stones containing the main components of silicate and aluminate were used as an alternative material to synthesize zeolite. The ability of pumice and zeolite was also tested for adsorbing one of cationic dyes, namely methylene blue (MB). Zeolites were synthesized through the hydrothermal method in high pH conditions and characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). The characterization results revealed that the addition of an alkaline solution changed the molecular structure of pumice into Na-P1 zeolite and caused differences in dye adsorption capacity. The adsorption efficiency of pumice was only achieved 65.83% with the MB uptake as much as 5.89 mg/g at the MB concentration of 50 mg/L for 24 hours, while the Na-P1 zeolite was able to adsorb MB molecules almost 100% with the uptake capacity up to 9.12 mg/g.