No abstract

Phenol is very abundant in the aquatic environment and therefore requires an effective treatment using porous and low-cost adsorbents. Alumina-hydroxyapatite composites were prepared from natural phosphate ore in the presence of Al 3+ ions via a wet-chemical method. Porous composites were characterized and the Al-surface modification was produced by facile and inexpensive route to uptake adjacent toxic species. Supplementary active sites on their surface may improve their phenol remediation. Nanocomposites exhibit higher phenol sorption rates than pure hydroxyapatite. It is concluded that the specific surface area, surface charge and Al content are suitable for phenol removal from aqueous solution using Alumina-hydroxyapatite composites. The results show that the retention power of these composites depends on a complex interaction between intermolecular and molecule-solid interactions. These findings are relevant to better understand the contribution of alumina content in Alumina-hydroxyapatite composites to the fate and uptake of phenol from aquatic environments.

Hydrophobic apatite monolith nanoparticles were prepared by grafting of dodecylphosphate (DP) onto hydroxyapatite. A modification in the synthesis was used to develop a hydrophobic surface in order to improve the dispersion and compatibility of organoapatite particles for the sensing and separation of hydrophobic substances. Results indicate that DP grafting onto the apatite is quantitative. Structural analyses of the as-received materials show that the grafting approach did not significantly alter the apatite microstructure, but modifies the hydrophobic character and surface properties of the hybrid material. Conversion of the hydrophilic surface of hydroxyapatite to hydrophobic was carried out to better retain naphthalene as a polynuclear aromatic hydrocarbon model.

This study develops cost-effective adsorbents for the treatment of water contaminated with phenolic compounds, including Phenol (Ph), 2-Chlorophenol (2-CPh), and 2-Nitrophenol (2-NPh). Therefore, Alumina-Hydroxyapatite composites were prepared from natural phosphate in the presence of Al3+ ions characterized by various techniques and then the supplementary active sites on their surface may make a better contribution to the phenols remediation. It was concluded that the specific surface area, surface charge and Al content were very suitable for the more adsorptive removal. Results show that the 2-chlorophenol is the more affinity versus hydroxyapatite and its formed composites compared to 2-NPh and Ph in order 2-CPh>2-NPh>Ph.

a b s t r a c tSurface of the natural phosphate and its converted hydroxyapatite was evaluated to develop an effective adsorbent suitable for the removal of individual oxymetal of Cr 6+ and Cr 3+ ions using batch system at room temperature. The converted hydroxyapatite was prepared from natural phosphate and characterized using various techniques. The experimental results suggest that several active sites exist on natural and synthetic apatite surfaces. They showed a high affinity of natural phosphate for the Cr 2 O 7 2-ions than c-HAP contrary to that of Cr 3+ ions related to the presence of silica in natural adsorbent while the converted apatite has a good affinity for Cr 3+ ions. The difference in adsorptive capacities is also related to the oxidation state of chromium and surface charge, which are effective parameters for Cr uptake on the natural and synthetic apatite.