The Influence of Synthesis Conditions on Hydroxyapatite Adsorption Characteristics in the Process of Zn(II) and Pb(II) Removal from Single and Binary Solutions

2018 ◽  
Vol 69 (4) ◽  
pp. 759-766
Author(s):  
Rodica Elena Patescu ◽  
Claudia Maria Simonescu ◽  
Gheorghe Nechifor ◽  
Christu Tardei ◽  
Ionela Camelia Ionascu
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Isotherm Models ◽  
Calcium Nitrate Tetrahydrate ◽  
Binary Solutions ◽  
Synthesis Conditions ◽  
Lead And Zinc ◽  
Nitrate Tetrahydrate

Two types of nanohydroxyapatite samples have been obtained by wet chemical precipitation synthesis, involving calcium nitrate tetrahydrate and diammonium hydrogen phosphate as precursors in different conditions. Powders obtained were characterized by X-ray diffraction (XRD) and FTIR spectroscopy. The equilibrium isotherm models related with lead and zinc ions removal from synthetic aqueous solutions have been also investigated. According to this research study, it has been found that the nanohydroxyapatite samples show good heavy metals adsorption capacity, and selectivity for lead ions. It was also observed a slow decreasing of sorption capacity of heavy metal ions from binary solutions compared to that registered from single heavy metal ion solutions.

Biomimetic Preparation of ha Precursors at 37°C in Urea- and Enzyme Urease-Containing Synthetic Body Fluids

1999 ◽  
Vol 599 ◽  
Author(s):  
D Bayraktar ◽  
A C. Tas
Keyword(s):  
Single Phase ◽  
Calcium Nitrate ◽  
Calcium Hydroxyapatite ◽  
Chemical Precipitation ◽  
Calcium Nitrate Tetrahydrate ◽  
Hydrogen Phosphate ◽  
Synthetic Bone ◽  
Nitrate Tetrahydrate ◽  
Phosphate Salts ◽  
Diammonium Hydrogen

AbstractAn important inorganic phase of synthetic bone applications, calcium hydroxyapatite (HA, Ca10(PO4)6(OH)2), was prepared as a single-phase and sub-micron bioceramic powder. Carbonated HA precursors were synthesized from calcium nitrate tetrahydrate and diammonium hydrogen phosphate salts dissolved in “synthetic body fluid” (SBF) solutions, containing urea (H2NCONH2) and enzyme urease, under the biomimetic conditions of 37°C and pH 7.4, by using a novel chemical precipitation technique.

scholarly journals Magnetic Hydroxyapatite for Batch Adsorption of Heavy Metals

2021 ◽  
Vol 287 ◽  
pp. 04005
Author(s):  
Khee Chung Hui ◽  
Norashikin Ahmad Kamal ◽  
Nonni Soraya Sambudi ◽  
Muhammad Roil Bilad
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Removal ◽  
Aqueous Media ◽  
Heavy Metal Removal ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Batch Adsorption ◽  
Calcium Nitrate Tetrahydrate ◽  
Removal Of Heavy Metals

In this work, magnetic hydroxyapatite or hydroxyapatite-iron (III) oxide (HAp-Fe3O4) composite was used as the adsorbent of heavy metals and the performance was evaluated using the batch test. The presence of heavy metals in the effluent from wastewater discharge can be toxic to many organisms and can even lead to eye burns. Therefore, hydroxyapatite synthesized from the chemical precipitation of calcium nitrate tetrahydrate and diammonium hydrogen phosphate solutions is used to remove heavy metal in aqueous media. Magnetic properties of Fe3O4 can help prevent formation of secondary pollutants caused by the loss of adsorbent. The synthesized HAp-Fe3O4 can remove cadmium, zinc and lead effectively, which is up to 90% removal. Reusability study shows that the adsorbent could retain heavy metal ions even after four cycles. The percentage removal of heavy metals maintains at around 80% after four times of usage. The composite of HAp-Fe3O4 demonstrates good performance and stability which is beneficial for heavy metal removal in the future.

Temperature Measurement of Single Levitated Microparticles Using Stokes/Anti-Stokes Raman Intensity Ratios

1994 ◽  
Vol 48 (12) ◽  
pp. 1498-1505 ◽  
Author(s):  
Scot D. Rassat ◽  
E. James Davis
Keyword(s):  
Temperature Measurement ◽  
Calcium Nitrate ◽  
Composition Analysis ◽  
Calcium Nitrate Tetrahydrate ◽  
Electrodynamic Balance ◽  
Beam Expander ◽  
Nitrate Tetrahydrate ◽  
Intensity Ratios ◽  
Anti Stokes ◽  
Heating Beam

A method has been developed to determine the temperature of single microparticles levitated in an electrodynamic balance. Particle temperatures were ascertained from the measured intensities of the Stokes and anti-Stokes Raman spectra. Temperatures near ambient were obtained for titanium dioxide and calcium nitrate microparticles with the use of a Raman-based calibration of the optical system to correct for wavelength-dependent effects. Higher temperatures were also measured with the use of a carbon dioxide infrared laser to electromagnetically heat the particle. In an effort to minimize particle instabilities caused by the heating beam, the Gaussian intensity profile of the beam was modified with an axicon beam expander to produce a doughnut-like intensity distribution. The temperature measurement technique and quantitative Raman composition analysis were applied to study dehydration of a calcium nitrate tetrahydrate particle.

Recent Advances in Water Treatment Using Graphene-based Materials

2020 ◽  
Vol 17 (1) ◽  
pp. 74-90 ◽  
Author(s):  
Nader Ghaffari Khaligh ◽  
Mohd Rafie Johan
Keyword(s):  
Heavy Metal ◽  
Water Treatment ◽  
Ion Exchange ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Membrane Filtration ◽  
Chemical Precipitation ◽  
High Specific Surface Area ◽  
Adsorption Parameters

: A variety of processes were reported for efficient removing of heavy metal from wastewater, including but not limited to ion exchange, reverse osmosis, membrane filtration, flotation, coagulation, chemical precipitation, solvent extraction, electrochemical treatments, evaporation, oxidation, adsorption, and biosorption. Among the aforementioned techniques, adsorption/ion exchange has been known as a most important method for removing heavy metal ions and organic pollutants due to great removal performance, simple and easy process, cost-effectiveness and the considerable choice of adsorbent materials. : Nanotechnology and its applications have been developed in most branches of science and technology. Extensive studies have been conducted to remove heavy metal ions from wastewater by preparation and applications of various nanomaterials. Nanomaterials offer advantages in comparison to other materials including an extremely high specific surface area, low-temperature modification, short intraparticle diffusion distance, numerous associated sorption sites, tunable surface chemistry, and pore size. In order to evaluate an adsorbent, two key parameters are: the adsorption capacity and the desorption property. The adsorption parameters including the absorbent loading, pH and temperature, concentration of heavy metal ion, ionic strength, and competition among metal ions are often studied and optimized. : Several reviews have been published on the application of Graphene (G), Graphene Oxide (GO) in water treatment. In this minireview, we attempted to summarize the recent research advances in water treatment and remediation process by graphene-based materials and provide intensive knowledge of the removal of pollutants in batch and flow systems. Finally, future applicability perspectives are offered to encourage more interesting developments in this promising field. This minireview does not include patent literature.

scholarly journals Synthesis of plate-like β-tricalcium phosphate nanoparticles and their efficiency in remineralization of incipient enamel caries

2019 ◽  
Vol 8 (4) ◽  
pp. 261-276
Author(s):  
Roghayyeh Marefat Seyedlar ◽  
Mohammadbagher Rezvani ◽  
Samira Barari ◽  
Mohammad Imani ◽  
Azizollah Nodehi ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Calcium Nitrate ◽  
Negative Control ◽  
Second Phase ◽  
Calcium Nitrate Tetrahydrate ◽  
Enamel Caries ◽  
Nitrate Tetrahydrate ◽  
Addition Rate ◽  
Post Hoc ◽  
Caries Lesions

AbstractThe purpose of this study was to synthesize nano-sized β-tricalcium phosphate (nano-TCP) particles and determine its concentration-dependent properties on incipient enamel caries lesions. Nano-TCP was synthesized as a wet chemical through a method using low concentration of precursors and low addition rate of calcium nitrate tetrahydrate as a second phase. Morphology and phase composition of the particles were analyzed by SEM, XRD, and EDXA techniques. Incipient enamel lesions were created in human premolars with an acidic buffer. The teeth were then incubated in aqueous dispersions of nano-TCP as remineralization solutions. Sodium fluoride solution and deionized water were used as positive and negative control groups, respectively. The quality and thickness of the remineralized layer on enamel were investigated using SEM. The data were statistically analyzed by analysis of variance (ANOVA) and post hoc Tukey’s test. The synthesized nano-TCP mostly consisted of porous platelet-like crystals of 50–100 nm thickness and pore diameters of 100–300 nm. SEM observation showed that a homogenous layer was formed on the surface of the enamels remineralized in nano-TCP solutions. The thickness of the mineralized layer was dependent on the incubation time and nano-TCP concentration.

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