Preparation of porous hydroxyapatite and its application in Pb ions effective removal

Abstract

Porous hydroxyapatite (HA) matrices with high porosity were prepared through a high temperature sintering method by using HA powder as raw material, polystyrene (PS) microspheres as pore-forming agents and polyvinyl alcohol (PVA) solution as adhesive. The characterization of HA was carried out by a series of techniques including XRD, FT-IR, FESEM and BET, and showed that the morphology and structure of porous HA material were closely related to the amount of PS and PVA. The adsorption capability for Cu2+, Cd2+ and Pb2+ in aqueous solution showed that the porous HA possessed a selective and strong uptake of Pb2+ ions and the adsorption efficiency reached 99.8% in 10 min.

Novel Hydroxyapatite Beads for the Adsorption of Radionuclides from Decommissioned Nuclear Power Plant Sites

“…Considering that ion exchange takes place as the main adsorption mechanism, this postulation is a reasonable way to interpret the selectivity of the adsorption process in this work. Our results are consistent with previous studies using hydroxyapatite-based materials as adsorbents for the uptake of metal ions [3,17,48].…”

“…The popularity lies in its particular structure and unique properties, such as its ion exchange capability, adsorptive ability, acidbase adjustability, and thermal stability [12][13][14][15][16]. The feasibility of hydroxyapatite (HdA) nanoparticles as effective adsorbents is well documented for the adsorption of various multi-valent metal ions, such as lead, cobalt, nickel, copper, zinc, cadmium, strontium, and uranium [1,[17][18][19]. Indeed, the HdA has a versatile structure, which allows foreign ions to substitute Ca-ions on the framework without any distortion [20].…”

Immobilization of Pectinase onto Porous Hydroxyapatite/Calcium Alginate Composite Beads for Improved Performance of Recycle

“…In the FT-IR spectra of CA beads ( Figure 1 c), the peaks at 3422.4, 2919.7, 1620.0, 1401.0, and 1028.7 cm –1 were attributed to the presence of OH – (stretching), C–H (stretching), C=O (asymmetric stretching), C=O (symmetric stretching), and C–O–C (stretching) vibrations, respectively. 8 For the porous HAp ( Figure 1 a), the characteristic peaks at 3570.0 and 632.0 cm –1 were assigned to the stretching and bending vibration of OH – , respectively. The characteristic peaks at 1091.0, 1033.2, 961.0, 602.1, 569.3, and 473.0 cm –1 were assigned to the stretching and bending vibration of PO 4 3– .…”

“…It has an excellent biocompatibility and bioactivity and is widely applied in the delivery of drugs, the separation of proteins, and the removal of heavy metal pollutants. 8 , 9 In this perspective, it is an ideal carrier for the immobilized enzyme. 10 − 13 In these studies, enzyme immobilized onto the porous HAp supports are highly stable.…”

“…Porous hydroxyapatite (HAp), with a chemical formula of Ca 10 (PO 4 ) 6 (OH) 2 , has a high specific surface area and superior mechanical properties. It has an excellent biocompatibility and bioactivity and is widely applied in the delivery of drugs, the separation of proteins, and the removal of heavy metal pollutants. , In this perspective, it is an ideal carrier for the immobilized enzyme. − In these studies, enzyme immobilized onto the porous HAp supports are highly stable . Although immobilized enzymes have many advantages, they still have disadvantages.…”