Adsorption and Kinetic Studies for Removal of Fluoride in Aqueous System by Activated Carbon Produced from Lemon Peels

Abstract

Globally, fluoride contamination in drinking water has been a major environmental problem, imposing severe threat to human health through various disease conditions. Therefore, the objective of this paper was to investigate the adsorption and kinetic studies for the removal of fluoride in aqueous system by activated carbon produced from lemon peels using appropriate standard procedures. Adsorptive efficiency of the lemon peel powder for fluoride ions in water was 94.90% at an optimum contact time of 100 minutes. The fluoride ions removal efficiency of the activated carbon was considered favourable and the data fitted-well to Langmuir and isothermal model with the regression coefficients (R²) of 0.992 respectively. The adsorption capacity was 0.02 mg/g. From this study, the defluoridation occurs through a chemisorption process when the adsorbent adsorbed fluoride ion from water. The adsorption kinetics studies were best described by pseudo-second order kinetics; the result obtained suggests an endothermic process with a strong regression coefficient (R²) of 0.998. The adsorbent used exhibited an excellent adsorption capacity due to its internal pore size, wide surface area and chemical nature. These findings reveal that lemon peel powder has the potential to effectively remove fluoride ions from aqueous solution and can be used to provide safe drinking-water.