Removal of ion Cu2+ and Pb2+ using zeolite NaP1 with the silica source utilized from rice husk ash

Abstract

Zeolite, as chemical essence, is an aluminosilicate mineral synthesized by rich-silica source, such as rice husk ash (RHA). This study focuses on the synthesis of zeolite NaP1  under a facial hydrothermal method  using the silica source utilized from RHA without any -pretreatment steps. The synthesis conditions of the synthesis are achieved at the molar ratio of 8 Na₂O: 6 SiO₂: 1 Al₂O₃, at 100^oC, 8 hours, and without aging. Scanning electron microscope (SEM), dynamic light scattering (DLS), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD) are used to determine the physical and chemical properties of the product. Adsorption results show that the optimal conditions are the initial concentration of 75 mg/L, adsorbent dose of 0.5 g/L, and contact time of 30 mins. Ion Cu²⁺ removal can reach a capacity and efficiency of 57.4 mg/g and 95.7%, respectively while Pb²⁺ adsorption can achieve a capacity and efficiency of 59.2 mg/g and 98.6%, respectively. Besides, Langmuir, Freundlich, Dubinin – Radushkevich (D-R), Temkin, Sips, and Redlich - Peterson models are also applied to describe the adsorption process.