Sorptive removal of fluoride from water using activated sugarcane bagasse (biochar)

Abstract

Drinking water contaminated by fluoride is recognized as a major public health problem in many parts of the world. Thus, the aim of this study was to investigate fluoride (F - ) adsorption onto activated sugarcane bagasse and investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH, agitation speed and absorbent dose. The result of the study showed that the optimum contact time for adsorption of Fon activated sugarcane bagasse reached to equilibrium at 60 min, at optimum adsorbent dose of 15 g/L, optimum pH ~5, equilibrium initial concentration of 5 mg/L, and shaking speed of 200 rpm. The sorption kinetics was found to follow pseudo-second-order model with R 2 = 0.993 rate and the experimental equilibrium sorption data fitted well to Freundlich isotherm model with R2 = 0.983. The efficiencies of the activated sugarcane bagasse towards the removal of fluoride from real sample were also examined and the fluoride content of groundwater sample were reduced from 16.75 mg/L to 8.95 mg/L without the pH adjustment. When the pH of the groundwater sample readjusted to optimum pH 5 the fluoride concentration was reduced from the original 16.75 mg/L to 5.62 mg/L. The study concludes application of activated sugarcane bagasse for the synthesis of an effective and low-cost adsorbent for water defluoridation. Enough attention should be given to defluoridation of water using locally available bisorbents.