Fluoride Removal from Drinking Water Using Chemically Modified Biosorbent Prepared from Citrus limetta : Chemical Characterization and Process Optimization

In present investigation, aluminum hydroxide-sweet lime biosorbent (AlOH-SL) was applied for defluoridation of groundwater. AlOH-SL biosorbent (1:3) was chemically characterized with the help of SEM-EDX, XRD, and FTIR. The defluoridation process was optimized against biosorbent dose, fluoride concentration, reaction time, and pH of the medium. Findings depicted that AlOH-SL has excellent fluoride removal potential (94.5% at 2ppm and 74% at 10ppm) at pH 6 with adsorbent dose of 5 mg/l. Time to saturation was found to be 30 min. Monolayer chemisorption of fluoride was confirmed by Langmuir isotherm ( R 2 =0.975) with pseudo-second order kinetics ( R 2 =0.985). Results gives direction towards utilizing wet waste can be energy efficient process for fluoride removal. The process shall be helpful in minimizing carbon footprint and supports the sustainable model of water decontamination. Further, utilization of discarded fruit peels provides opportunity to generates wealth from waste and moderation of waste management. Graphical Abstract