LAUSR

Abstract The present study explores the feasibility of using crystalline zeolite NaA derived from rice husk ash as a potential adsorbent in removing fluoride from aqueous solution. BET surface area analyzer, SEM and FTIR were used to characterize the synthesized zeolite. The influence of five parameters viz. pH (2−8), initial concentration (1–20 mg/L), adsorbent dosage (15–150 mg), contact time (0–6 h) and temperature (30–65 °C) on fluoride uptake were investigated. Proximate analysis of rice husk was also carried out. Maximum adsorption capacity of the adsorbent was 22.83 mg/g and the Freundlich isotherm model fitted well to the experimental data. The adsorption process obeyed pseudo-second order kinetics. Thermodynamic parameters ( ΔG° ), ( ΔH° ) and ( ΔS° ) predicted the endothermic nature, randomness, spontaneity and feasibility of the adsorption process. Cost analysis also suggested the cost-effectiveness of the adsorbent used. Results reveal that zeolite NaA can be considered a promising and cost-effective adsorbent in treatment of fluorinated wastewater.