Synthesis, characterization, and application of nano hydroxyapatite and nanocomposite of hydroxyapatite with granular activated carbon for the removal of Pb2+ from aqueous solutions

Improved nanocomposite of montmorillonite and hydroxyapatite for defluoridation of water

“…Nano hydroxyapatite was synthesized according to the modied method reported earlier by us. 7 In brief (NH 4 ) 2 HPO 4 was added dropwise into Ca(NO 3 ) 2 $4H 2 O solution maintaining the Ca/P ratio to 1.67 at 60 C with vigorous stirring. The pH was maintained at 10 with dropwise addition of NH 4 OH (5 M) and then the mixture was vigorously stirred at its boiling point for about 3 h. The mixture was aged for 24 hours at room temperature and the HAP precipitate was washed until its pH became neutral.…”

“…In order to identify the improved adsorption properties of the HAP-MMT nanocomposite at the drinking water pH levels, the adsorption studies were carried out separately for HAP, MMT, HAP-MMT composites and also for a physical mixture of HAP, MMT with 1 : 1 ratio at different pH levels. [2][3][4][5][6][7][8][9][10][11] Experiments were conducted for 20 ml of 10 ppm uoride solutions and the dose of the adsorbent at 0.04 g.…”

“…5,6 Among the existing water deuorination methods, adsorption has been identied as one of the best methods and has been extensively studied and reviewed. [7][8][9][10][11][12][13] In comparison to the different types of bulk materials which have been studied for uoride adsorption, metal oxides and hydroxides of titanium, 5,14 iron, 15,16 lanthanum 17 and aluminium 18 are identied as the most frequently studied materials with higher adsorption capacities. Further, different types of nanomaterials including other metal oxides 11,[19][20][21][22] metal oxide hybrids 23,24 and hydroxides, 22,[25][26][27][28] and carbon nanotubes, [29][30][31] have also been tested on removing uoride ions.…”

The state of nanomedicine in Sri Lanka: challenges and opportunities

“…It has also been recognized that there has been a marked increase of kidney diseases among the rural population in Sri Lanka mainly due to the accumulation of chronic biological and chemical toxins in drinking water. Because of this requirement of the country, many research groups have focused on developing materials to remove biological toxins, heavy metals, and other dye contaminants in drinking water using biocompatible nanocomposites (Udayakantha et al, 2015;Jayaweera et al, 2018;Manatunga et al, 2016;Manatunga et al, 2018b;Fernando et al, 2015), and one such approach is depicted in Figure 3. Application of some of these materials in water purification systems is already established (Wasana et al, 2016).…”

Removal of Cd2+ by hydroxyapatite adsorption granule from aqueous solution

“…HAp can remove of several contaminated agents such as Cu 2+ , Pb 2+ , Zn 2+ , Cd 2+ , Co 2+ , Ni 2+ ,... [7][8][9][10][11][12] and NO 3 -, PO 4 3-, F -, phenol, nitrobenzene, congo red [13][14][15][16][17][18] from aqueous solution. Depending on application purpose, HAp is prepared in different forms, including powder, membrane, composite and ceramic by physical, chemical, electrochemical methods.…”