HaP/SBA-3 Nanostructured Composite to Remove Fluoride Effectively from Contaminated Water

Nanostructured materials, based on silica (MCM, SBA [1,2]) and ordered mesoporous carbon (OMC), such as CMK-1, CMK-3 [3] and Multi-Walled Carbon Nanotubes (MWCN) [4], because of their large surface area, pore volume and possibility to vary the pore size, offer a great opportunity for their application in various fields, from industrial processes to biomedical engineering, air and water pollution decontamination and energy reservoirs. Recently, we have developed a technique of preparation of monocrystalline hydroxyapatite (HaP) , and by the same procedure, but in the presence of the respective hosts, forming in situ composites such as HaP/MCM-41 and HaP/SBA15 composites [5]. Numerous approaches for fluoride removal from contaminated water, such as precipitation-coagulation [6], membrane technology [7,8], ion exchange [9] and adsorption [10,11]. Among the above methods, fluoride adsorption on adsorbents is attracting increasing attention due to its advantages of convenient design and operation, and low cost [12]. Different types of adsorbents, such as metal adsorbents [13], carbon adsorbents [14], carbon materials [15], natural materials [16], and biosorbents [17], have been used to remove fluoride from water. MOFs have also been used as new adsorbents for fluoride adsorption due to their surface functional groups and ordered atomic arrangement [18]. Calcium phosphate apatites are compounds of the formula Ca5 (PO4)3X, where X can be an Fion (fluorapatite, FaP), OH(hydroxyapatite, HaP), or a Clion (chlorapatite). The ion is substituted by another ion of the same sign but of different charge. Neutrality is maintained by substitutions of ions with different charges or vacancies [19]. Studied the crystallization of HaP (hydroxyapatite) on polymers containing C-N groups, from supersaturated solutions of HaP has been reported [20]. The growth of hydroxyapatite on silica gels in the presence of organic additives was studied by Rivera-Muñoz et al. [21]. Laghzizil et al. [22] have correlated the results of HaP fluorination with the physicochemical properties of HaP. Recently, morphological modifications of hydroxyapatite using fatty acids as an organic modifier have been reported [23]. The goal of this work is the successful Crimson Publishers Wings to the Research Short Communication