“…Adsorption is one of the most used methods for defluoridation due to its simple operation, low energy consumption, and low cost, compared with other methods such as ion exchange (Sundaram and Meenakshi, 2009), coagulation (He et al, 2016;Gan et al, 2019), flocculation (Wang et al, 2013), precipitation (Lu and Liu, 2010), reverse osmosis (Shen and Schä fer, 2015;Owusu-Agyeman et al, 2019) and electrodialysis (Grzegorzek and Majewska-Nowak, 2016).…”