Senna auriculata L. flower petal biomass: An alternative green biosorbent for the removal of fluoride from aqueous solutions

Fluoride contamination in groundwater is a major concern in many parts of India and all over the world. Researches paying attention for the removal of fluoride through the application of biosorbents prepared from different parts of plants are finding greater scope and importance. The present research work focuses on Senna auriculata L., flower petal biomass as biosorbent, and evaluated its feasibility for fluoride ion elimination from aqueous solutions. Batch experiments were conducted to remove fluoride under different experimental conditions have been optimized for the maximum removal of fluoride; 80% removal was observed at pH: 6, sorbent dosage: 0.25 g/100 mL, time of agitation: 90 min, and initial concentration of the fluoride ions: 5 mg/L. Characterization studies of the biosorbent revealed its favorability towards the sorption of fluoride. In the isothermal modeling studies, Langmuir isotherm model was obeyed by the biosorption process with R² value of 0.98 and from a kinetic perspective, the biosorption of fluoride onto the biosorbent observed the pseudo-second-order reaction with R² value of 0.98. The developed biosorbent has been applied to real field fluoride-contaminated water samples and found to be successful.