Fluoride deficiency and toxicity severely affect a large population globally. Hence, a low‐cost geosorbent is in demand to overcome fluorosis hazards where in situ retardation is prioritized over pilot‐scale waste water treatment. This study reports the fluoride removal potential of MgFe‐type layered double hydroxide (HT‐LDH) and its calcined form at 500 and 800°C for their usability for treatment of polluted streams, ponds, wells, and hot spring water. Rapid uptake with >33% removal in 24 h was found by the adsorptive method, whereas the co‐precipitation process removed >16 mg/L (>83%) in 1 h. The efficiency was further enhanced upon calcination at 500°C with >95% removal up to five times regeneration, unlike that at 800°C. It was demonstrated that multilayer sorption onto heterogeneous surface sites is majorly controlled by surface adsorptive and ion exchange mechanisms. Acidic pH, low aqueous
F−, and temperature >25°C favored greater uptake, whereas competitive anions slightly enhanced its potential in the order
normalNO3−>normalSO42−>normalPO43− in adsorptive removal. In the co‐precipitation process, competing anions slightly hindered
F− retention, whereas high temperature and low aqueous
F− led to greater
F− retention. No F‐bearing solid phases were evidenced upon its retention, except lowering the HT‐LDH crystallinity and rearrangement of
normalCO32− surface functional groups. The fluoride contents of natural water were lowered drastically up to 77% in 60 min upon precipitation of HT‐LDH by maintaining alkalinity and a di‐/trivalent cationic ratio of 2.0.
Practitioner Points
F^− uptake is rapid on heterogeneous surface sites with multilayer sorption mechanism
Greater F^− removed by coprecipitation technique compared with adsorptive pathway
Acidic medium and temperature >25°C favor greater F^− retention NO_3^−+PO_l4^(3−) slightly enhanced F^− uptake by adsorption but lowered in coprecipitation
Formation of LDH from natural waters lowered F^− content up to <77%
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.