Fluoride Action Network

Biosorptive removal of fluoride from aqueous solution onto newly developed biosorbent from Ficus benghalensis leaf: Evaluation of equilibrium, kinetics, and thermodynamics

Source: Sustainable Chemistry and Pharmacy 10:125-133. | December 15th, 2018 | Authors: George Am, Tembhurkar AR.
Location: International
Industry type: Water Treatment


Need for developing an effective defluoridation method using locally available resources and recycling of agriculture waste is still encouraging the researchers for achieving sustainability. Greater attention was shown towards developing biosorbent for deflouridation utilisation of locally available plant biomass such as leaves. Present research envisages on developing a novel biosorbent from Ficus benghalensis leaf and tests its feasibility for removal of fluoride. Batch mode experimentations are conducted to evaluate its feasibility and determine the equilibrium, kinetic and thermodynamic characteristics of this biosorption process. The study revealed that the biosorption of fluoride onto this newly developed Ficus benghalensis leaf biosorbent obeys Langmuir isotherm with constants ‘a’ and ‘b’ calculated to be 2.242 mg/g and 0.647 L/mg at biosorbent dose of 8?g/L and temperature 26 ± 1ºC. The kinetic study indicates sorption data fits fine with Pseudo-second order kinetic model with kinetic constant calculated as K2 0.277 g/mg min at equilibrium contact period of 90 min. The thermodynamic study points out the spontaneous and endothermic nature of fluoride sorption with H= 15.497 KJ/mol. Advanced analysis viz BET, SEM, and FTIR were done to know the characteristic of the newly developed biosorbent. When this biosorbent was tested on field groundwater sample, the efficacy for fluoride removal was found to be around 90%, and the concentration for treated water is well within drinking water standards for fluoride.