Cobalt adsorption on the nano-hydroxyapatite matrix: isotherm and kinetic studies

Abstract

Abstract. Cobalt radionuclide is one of the prime contaminants generated during operation of pressurized heavy water. The paper reports the study of cobalt adsorption on hydroxyapatite (HAp) nanoceramic. A modified wet chemical precipitation method is used for HAp synthesis. The HAp nano-material is characterized by XRD, FTIR, TG/DTA, AFM, SEM, and EDAX. Experiments are performed in batches to observe the effect of cobalt adsorption on HAp matrix. The adsorption of cobalt on HAp is examined at room temperature. The isotherm and kinetic studies showed that the Freundlich isotherm and pseudo-second order model are the best choices to describe the nature of adsorption. The pH of the reaction mixture is adjusted by the addition of NH 4 OH. As a result of reaction, milky precipitate is obtained. In the wet chemical process, the precipitate is continuously stirred

The Ultra-morphological Evaluation of Conventional and Resin-Modified Glass Ionomer Cements Modified with Nano-Hydroxyapatite Particles at Sound and Caries-Affected Dentin Interfaces

“…The result of SEM and TEM photomicrographs for the prepared Nano-HAp (Fig. 1& 3) showed well defined uniform shape nano rod HAp with a length varying from (20-80) nm and diameter varying from (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) nm. This considers the optimal form for the nano-hydroxyapatite crystals that provide high physical and chemical properties (24) .…”

“…No differences were observed in the photomicrographs appearance of the restoration-dentin interface between control groups (CGIC and RMGIC) and their modified experimental groups (Nano-HA GIC and Nano-HA RMGIC) (Fig. [4][5][6][7][8][9][10][11].…”

“…Nano-hydroxyapatite particles (Nano-HAp) were synthesized for this study by the wet-chemical precipitation method at National Research Centre, Egypt (10) . Synthesized Nano-HAp was then characterized by Scanning Electron Microscopy (SEM), Elemental Dispersive X-ray (EDX) and Transmission Electron Microscopy (TEM) to study the powder purity, surface area and the particle size which affect their bioactivity, mechanical and biological properties.…”

Hydroxyapatite‐Graphene Oxide Nanocomposite with Enhanced Ammonia Sensing Property

“…In this experiment, 0.6 M di‐ammonium hydrogen phosphate and 1 M calcium nitrate tetrahydrate are utilized as starting precursors to obtained a Ca/P ratio of 1.67. [ 3,15 ] The synthesis process starts via drop‐wise addition of aqueous phosphate solution in aqueous calcium solution. Throughout the synthesis, pH is maintained at 10 by adding ammonia solution.…”

Enhanced catalytic activity of Bacillus aryabhattai P1 protease by modulation with nanoactivator

“…The precipitation was carried out by the drop-wise addition of 0.6 M di-ammonium hydrogen phosphate into 1 M calcium nitrate tetrahydrate solution, under constant stirring of 150 rpm at 80 C for 4 h, followed by aging for about 24 h. The white precipitates were then washed 3-4 times with milliQ water to remove the rest of the precursors, and dried in a hot air oven at 100 C. The dried sample was further annealed at 1000 C for phase formation. AFM and XRD analyses of the preparation phase were performed for checking crystalline nature and finding grain size [52,53,54,55,56,57].…”