Kinetics of Nucleation of Lead Hydroxylapatite and Preparation of Solid Solutions of Calcium—Cadmium—Lead Hydroxylapatite: An X-Ray and IR Study

Mahapatra, P. P.; Sarangi, Debakanta; Mishra, Braja Kishori

doi:10.1006/jssc.1995.1175

Cited by 7 publications

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“…All bands, especially the P–O stretching ( v 3 ) bands, weaken with the increasing X Pb due to the IR beam scattering of large particles [ 10 ]. The strong sharp bands at 3553.83–3571.67 cm −1 represent the stretching vibrations of the bulk OH − and the band at 3735.15–3736.56 cm −1 represents the surface P-OH groups [ 15 , 35 ]. The band at 1455 cm −1 for CO 3 2− vibration [ 36 ] and the band at 871 cm −1 for HPO 4 2− [ 10 , 11 ] are not visible in the FT-IR spectra of the present work.…”

Section: Resultsmentioning

confidence: 99%

“…Calcium hydroxyapatite [Ca-HAP] is the main component of vertebral animals’ bones [ 10 – 15 ]. Commonly, natural apatites as raw materials for the phosphate fertilizer industry contain some traces amount of various elements [ 10 ], among which lead and cadmium are predominantly risky and may be redistributed in natural waters, soil and agricultural products, especially in rice and vegetables.…”

Section: Introductionmentioning

confidence: 99%

“…Commonly, natural apatites as raw materials for the phosphate fertilizer industry contain some traces amount of various elements [ 10 ], among which lead and cadmium are predominantly risky and may be redistributed in natural waters, soil and agricultural products, especially in rice and vegetables. When these toxic heavy metals are taken into animals through food chains, they may concentrate in animals’ hard tissues through the possible substitution, which can cause osteoporotic processes and dental caries [ 10 – 13 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

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Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

et al. 2016

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BackgroundThe interaction between Ca-HAP and Pb2+ solution can result in the formation of a hydroxyapatite–hydroxypyromorphite solid solution [(PbxCa1−x)5(PO4)3(OH)], which can greatly affect the transport and distribution of toxic Pb in water, rock and soil. Therefore, it’s necessary to know the physicochemical properties of (PbxCa1−x)5(PO4)3(OH), predominantly its thermodynamic solubility and stability in aqueous solution. Nevertheless, no experiment on the dissolution and related thermodynamic data has been reported.ResultsDissolution of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3(OH)] in aqueous solution at 25 °C was experimentally studied. The aqueous concentrations were greatly affected by the Pb/(Pb + Ca) molar ratios (XPb) of the solids. For the solids with high XPb [(Pb0.89Ca0.11)5(PO4)3OH], the aqueous Pb2+ concentrations increased rapidly with time and reached a peak value after 240–720 h dissolution, and then decreased gradually and reached a stable state after 5040 h dissolution. For the solids with low XPb (0.00–0.80), the aqueous Pb2+ concentrations increased quickly with time and reached a peak value after 1–12 h dissolution, and then decreased gradually and attained a stable state after 720–2160 h dissolution.ConclusionsThe dissolution process of the solids with high XPb (0.89–1.00) was different from that of the solids with low XPb (0.00–0.80). The average Ksp values were estimated to be 10−80.77±0.20 (10−80.57–10−80.96) for hydroxypyromorphite [Pb5(PO4)3OH] and 10−58.38±0.07 (10−58.31–10−58.46) for calcium hydroxyapatite [Ca5(PO4)3OH]. The Gibbs free energies of formation (ΔGfo) were determined to be −3796.71 and −6314.63 kJ/mol, respectively. The solubility decreased with the increasing Pb/(Pb + Ca) molar ratios (XPb) of (PbxCa1‒x)5(PO4)3(OH). For the dissolution at 25 °C with an initial pH of 2.00, the experimental data plotted on the Lippmann diagram showed that the solid solution (PbxCa1−x)5(PO4)3(OH) dissolved stoichiometrically at the early stage of dissolution and moved gradually up to the Lippmann solutus curve and the saturation curve for Pb5(PO4)3OH, and then the data points moved along the Lippmann solutus curve from right to left. The Pb-rich (PbxCa1−x)5(PO4)3(OH) was in equilibrium with the Ca-rich aqueous solution.Graphical abstractLippmann diagrams for dissolution of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 ˚C and an initial pH of 2.00.Electronic supplementary materialThe online version of this article (doi:10.1186/s12932-016-0034-8) contains supplementary material, which is available to authorized users.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

et al. 2016

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“…The calcium in hydroxyapatite [Ca 5 (PO 4 ) 3 OH, Ca-HAP] can be substituted by different divalent cations such as Pb 2+ [1][2][3][4][5][6]. When the toxic lead ions, which may be found in surface and underground waters, are taken into animals, it is possible that they concentrate in animals' hard tissues through the substitution of Pb 2+ for Ca 2+ and form the Pb-Ca hydroxyapatite solid solution with vital calcium hydroxyapatite and can finally cause many bone diseases, such as osteoporotic processes and dental caries [1,[7][8][9]. The synthetic or natural calcium hydroxyapatite (Ca-HAP) from different sources can be used to remove toxic lead ions from industrial wastewaters [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Characterization, Dissolution, and Solubility of Lead Hydroxypyromorphite [Pb₅(PO₄)₃OH] at 25–45°C

Zhu

Zhao

et al. 2015

Journal of Chemistry

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Dissolution of the hydroxypyromorphite [lead hydroxyapatite, Pb5(PO4)3OH] in HNO3solution (pH = 2.00), ultrapure water (pH = 5.60), and NaOH solution (pH = 9.00) was experimentally studied at 25°C, 35°C, and 45°C. The XRD, FT-IR, and FE-SEM analyses indicated that the hydroxypyromorphite solids were observed to have indistinguishable change during dissolution. For the hydroxypyromorphite dissolution in aqueous acidic media at initial pH 2.00 and 25°C, the aqueous phosphate concentrations rose quickly and reached the peak values after 1 h dissolution, while the aqueous lead concentrations rose slowly and reached the peak values after 1440 h. The solution Pb/P molar ratio increased constantly from 1.10 to 1.65 near the stoichiometric ratio of 1.67 to 209.85~597.72 and then decreased to 74.76~237.26 for the dissolution at initial pH 2.00 and 25°C~45°C. The averageKspvalues for Pb5(PO4)3OH were determined to be 10−80.77(10−80.57−10−80.96) at 25°C, 10−80.65(10−80.38−10−80.99) at 35°C, and 10−79.96(10−79.38−10−80.71) at 45°C. From the obtained solubility data for the dissolution at initial pH 2.00 and 25°C, the Gibbs free energy of formation [ΔGfo] for Pb5(PO4)3OH was calculated to be −3796.71 kJ/mol (−3795.55~−3797.78 kJ/mol).

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Structural and spectroscopic characterizations in Pb2+-doped calcium hydroxyapatites

Mehnaoui

Panczer

Ternane³

et al. 2008

Optical Materials

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Kinetics of Nucleation of Lead Hydroxylapatite and Preparation of Solid Solutions of Calcium—Cadmium—Lead Hydroxylapatite: An X-Ray and IR Study

Cited by 7 publications

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Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

Characterization, Dissolution, and Solubility of Lead Hydroxypyromorphite [Pb₅(PO₄)₃OH] at 25–45°C

Structural and spectroscopic characterizations in Pb2+-doped calcium hydroxyapatites

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Kinetics of Nucleation of Lead Hydroxylapatite and Preparation of Solid Solutions of Calcium—Cadmium—Lead Hydroxylapatite: An X-Ray and IR Study

Cited by 7 publications

References 0 publications

Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

Characterization, Dissolution, and Solubility of Lead Hydroxypyromorphite [Pb5(PO4)3OH] at 25–45°C

Structural and spectroscopic characterizations in Pb2+-doped calcium hydroxyapatites

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Characterization, Dissolution, and Solubility of Lead Hydroxypyromorphite [Pb₅(PO₄)₃OH] at 25–45°C