Removal of fluoride using modified biochar from contaminated water ecosystem

Biochar is a renewable carbonaceous material obtained from pyrolyzed biomass at certain temperatures under low/zero oxygen. It has been extensively applied for environmental applications, such as carbon sequestration, contaminants removal, bio-energy production, and wastewater treatment. This work aims to reduce fluoride levels under permissible limits from contaminated water using modified biochar. In this work, we have synthesized modified biochar, i.e., activated biochar and activated magnetic biochar from rice husk, and performed an adsorptive approach for fluoride removal from contaminated waters. It was observed that the activated magnetic biochar achieved high removal efficiency (98.13%) of low fluoride concentration (10 mg/l) as compared to the activated or raw biochars. The fluoride removal analysis was implemented under the influence of contact time, initial fluoride concentrations, biochar dosage, pH, temperatures, and co-existing ions. Besides, adsorption isotherms, kinetics, and thermodynamics analysis were also performed using biochars. Significantly, activated magnetic biochar was performed to remove fluoride from contaminated groundwater and surface water. This study showed activated magnetic biochar as a potential and practical biosorbent for fluoride removal and other pollutants.