Investigation of Physicochemical Characteristics for Alumina Selection for Fluoride and Arsenic Removal

This study attempts a correlation of physicochemical characteristics of four commercially available activated alumina samples with their efficacy towards harmful ions such as fluoride and arsenic removal to enable identification and possible preparation of suitable varieties. The equilibrium adsorption capacities of alumina samples for fluoride and arsenic were measured by batch experiments under mechanical stirring, wherein two samples labeled AA-1 and AA-2 have shown high fluoride (~90%) and arsenic (57–72%) removal. Surface area, phase composition by powder XRD, infrared spectroscopy, and weight loss with temperature (TGA), point of zero charge of alumina varieties were characterized. Alumina varieties better suited for fluoride and arsenic removal, AA-1 and AA-2, were found to have good surface area (~300 m2/g), positively charged surface (pHpzc ~ 9) and consist mainly of amorphous phases.