Preparation, characterization, and stability of calcium zinc hydrophosphate

Qian, Guangren; Xu, Xia; Sun, Weimin; Xu, Yunfeng; Liu, Qiang

doi:10.1016/j.materresbull.2008.01.022

Cited by 17 publications

(7 citation statements)

References 26 publications

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“…For Zn-phosphate minerals this is attributed to differences in configuration of phosphate tetrahedra due to a range of P–O bond lengths and angles, and the degree of interaction with adjacent Zn polyhedra. , However, the band shape for the samples is distinct from that observed for Zn-phosphates, and at low Zn concentrations where the effect is most pronounced such phases are undersaturated (SI Table S1). Such effects can be induced by the interaction of phosphate minerals with foreign ions, including substitutions into mineral structures. − Therefore, the observed splitting in the ν 3 PO 4 3– band indicates distortion of the phosphate tetrahedron due to direct interaction of Zn with struvite phosphate groups induced by Zn incorporation into the mineral structure. In turn, phosphate tetrahedra directly bound to Zn would be expected to have configurations distinct from those of the bulk mineral.…”

Section: Resultsmentioning

confidence: 99%

Zinc Interaction with Struvite During and After Mineral Formation

Rouff

Juarez

2014

Environ. Sci. Technol.

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Sorption of Zn with struvite was assessed both during and after mineral formation at pH 9.0 for 1-100 μM (0.065-6.54 mg L(-1)) aqueous Zn. The Zn loadings of recovered solids were lower when Zn was present during struvite precipitation compared to when Zn was added to struvite-bearing solutions. X-ray absorption fine structure spectroscopy confirmed that Zn added to struvite-bearing solutions at concentrations≤5 μM sorbed as both octahedral and tetrahedral complexes (Zn-O 1.98-2.03 Å), with evidence for bidentate configuration (Zn-P 3.18 Å). Bidentate complexes were incorporated into the near-surface structure, contributing to distortion of the struvite ν3 PO4(3-) band in the Fourier transform infrared spectra. At Zn concentrations>5 μM, tetrahedral monodentate adsorbates (Zn-O 1.98 Å) dominated, transitioning to a Zn-phosphate precipitate at 100 μM. When Zn is present during struvite precipitation, octahedral monodentate sorbates detected at 1 μM (Zn-O 2.08-2.10 Å; Zn-P 3.60-3.64 Å) polymerized at 5-50 μM, ultimately forming a Zn-hydroxide precipitate at 100 μM. The lowest initial Zn concentrations (0.065 mg L(-1)) and resultant solid loadings from precipitation experiments (13 mg kg(-1)) are consistent with those reported for struvite recovered from wastewater, suggesting that similar Zn sorption processes may occur in more complex systems.

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Section: Resultsmentioning

confidence: 99%

Zinc Interaction with Struvite During and After Mineral Formation

Rouff

Juarez

2014

Environ. Sci. Technol.

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“…In comparison, the addition of sodium phosphate converted metal chlorides into phosphate or other phosphate-like minerals, which were chemically stable [35,36]. Fig.…”

Section: Chemical Composition and Dominant Phases Of Mswi Fly Ash Befmentioning

confidence: 99%

Inhibiting evaporation of heavy metal by controlling its chemical speciation in MSWI fly ash

Sun

et al. 2015

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“…More recently, hydroxyapatite, has been proposed as a inexpensive but efficient adsorbent for removal/remediation of soils polluted by Pb (Hashimoto et al, 2009;Slobodan, 2009), Zn and Cd (Chen et al, 2007;Zhu et al, 2008) and Cu-, Znpolluted wastewater (Qian et al, 2008;Wang et al, 2009). Besides phosphates, activated carbons are considered also an efficient treatment for the removal of many organic compounds and metals from both liquid and gas phases (Cheung et al, 2002;Danny et al, 2004;Xiao and Thomas, 2004;Chen et al, 2006), but expensive.…”

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Adsorption of aqueous Cd2+, Pb2+, Cu2+ ions by nano-hydroxyapatite: Single- and multi-metal competitive adsorption study

Chen

et al. 2010

Geochem. J.

162

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Being an inexpensive but efficient adsorbent, hydroxyapatite is extensively used for decontaminating wastewater and soils polluted by heavy metals. However, its solubility and grain size can affect its remediation effectiveness. This study investigated the ability of nano-hydroxyapatite (nano-HAP) to adsorb aqueous Cd, Pb and Cu ions from single-metal and multi-metal ions reaction systems. Langmuir and Freundlich isotherm equations were employed to study the sorption constants. Based on the sum of squares errors (SSE), results showed that the Langmuir isotherm better fits sorption data than the Freundlich equation. The sorption affinity of nano-HAP for Pb(II) is always higher than that for Cu(II) and for Cd(II); the sorption maxima for the Cd, Pb and Cu follow the order Pb 2+ > Cu 2+ > Cd 2+ . This could be inversely proportional to the hydrated ionic radii as Pb 2+ (4.01 Å) > Cu 2+ (4.19 Å) > Cd 2+ (4.26 Å). The measured selectivity coefficients in multi-metal (Cd-Pb-Cu) reaction systems shows that Pb has the highest sorption selectivity on nano-HAP among the metals investigated. This sorption selectivity coincided well with the sorption affinity order in mono-metal reaction systems. The pH of the solution is an important parameter in controlling Cd, Pb and Cu ions sorption on nano-HAP. Indeed, the nano-HAP sorption capacity increases with increasing pH up to a value of 6.25. This implies that the removal of metals from the solution is recommended for pH ≈ 6.25 or below, during remediation using nano-HAP as a sorbent.

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Preparation, characterization, and stability of calcium zinc hydrophosphate

Cited by 17 publications

References 26 publications

Zinc Interaction with Struvite During and After Mineral Formation

Zinc Interaction with Struvite During and After Mineral Formation

Inhibiting evaporation of heavy metal by controlling its chemical speciation in MSWI fly ash

Adsorption of aqueous Cd2+, Pb2+, Cu2+ ions by nano-hydroxyapatite: Single- and multi-metal competitive adsorption study

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