Adsorption and precipitation of fluoride on calcite nanoparticles: A spectroscopic study

Budyanto, Sukamto; Kuo, Yu‐Lin; Liu, J.C.

doi:10.1016/j.seppur.2015.07.016

Cited by 73 publications

(15 citation statements)

References 22 publications

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“…Since when the dosage of calcite reached 2 g/L, the residual F − concentration in wastewater dropped to 11.41 mg/L, and the removal rate reached 96.20%. As reported in several studies [42,43], when the fluoride concentration is lower (<~10 mg/L), the fluoride adsorption on the surface of calcite may play a dominant role. When the calcite dosage exceeded 2 g/L, the fluoride adsorption of excessive calcite become dominant.…”

Section: Precipitation Experiments In Simulated Systemmentioning

confidence: 77%

Precipitation Methods Using Calcium-Containing Ores for Fluoride Removal in Wastewater

et al. 2019

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F-containing wastewater does great harm to human health and the ecological environment and thus needs to be treated efficiently. In this paper, the new calcium-containing precipitant calcite and aided precipitant fluorite were adopted to purify F-containing wastewater. Relevant reaction conditions, such as reaction time, oscillation rate, dosage of hydrochloric acid, calcite dosage and the assisting sedimentation performance of fluorite, and action mechanism are analyzed. The experiment showed that the removal rate of fluoride in simulated wastewater reached 96.20%, when the reaction time, the dosage of calcite, the dosage of 5% dilute hydrochloric acid, and the oscillation rate was 30 min, 2 g/L, 21.76 g/L, and 160 r/min, respectively. Moreover, the removal rate of fluoride in the actual F-containing smelting wastewater reaches approximately 95% under the optimum condition of calcite dosage of 12 g/L, reaction time of 30 min, and oscillation rate of 160 r/min. The addition of fluorite significantly improves the sedimentation performance of the reactive precipitates. The experimental results showed that calcite and fluorite can effectively reduce the concentration of fluoride ions in F-containing wastewater and solve the problem of slow sedimentation of reactive precipitates.

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Section: Precipitation Experiments In Simulated Systemmentioning

confidence: 77%

Precipitation Methods Using Calcium-Containing Ores for Fluoride Removal in Wastewater

et al. 2019

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“…It clearly exhibits two prominent peaks arising from the two elements constituting this sample, that is, fluorine (F1s) and calcium (Ca2p); it also exhibits less intense peaks related to carbon (C1s) and oxygen (O1s). The C1s peak can be deconvoluted into its 3 components, C-C/C-H, C-O, and C=O, centered at 285.0 eV, 285.7 eV, and 288.8 eV, respectively ( Figure 4 E) [ 40 ]. The C1s peak most likely originated from a background source, i.e., the tape used to mount the sample onto the XPS holder [ 30 , 36 ].…”

Section: Resultsmentioning

confidence: 99%

Bimodal Ultrasound and X-ray Bioimaging Properties of Particulate Calcium Fluoride Biomaterial

et al. 2021

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Ultrasound (US) and X-ray imaging are diagnostic methods that are commonly used to image internal body structures. Several organic and inorganic imaging contrast agents are commercially available. However, their synthesis and purification remain challenging, in addition to posing safety issues. Here, we report on the promise of widespread, safe, and easy-to-produce particulate calcium fluoride (part-CaF2) as a bimodal US and X-ray contrast agent. Pure and highly crystalline part-CaF2 is obtained using a cheap commercial product. Scanning electron microscopy (SEM) depicts the morphology of these particles, while energy-dispersive X-ray spectroscopy (EDS) confirms their chemical composition. Diffuse reflectance ultraviolet-visible spectroscopy highlights their insulating behavior. The X-ray diffraction (XRD) pattern reveals that part-CaF2 crystallizes in the face-centered cubic cell lattice. Further analyses regarding peak broadening are performed using the Scherrer and Williamson–Hall (W-H) methods, which pinpoint the small crystallite size and the presence of lattice strain. X-ray photoelectron spectroscopy (XPS) solely exhibits specific peaks related to CaF2, confirming the absence of any contamination. Additionally, in vitro cytotoxicity and in vivo maximum tolerated dose (MTD) tests prove the biocompatibility of part-CaF2. Finally, the results of the US and X-ray imaging tests strongly signal that part-CaF2 could be exploited in bimodal bioimaging applications. These findings may shed a new light on calcium fluoride and the opportunities it offers in biomedical engineering.

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“…Since F − -adsorption is selective, easily handled, lowcost and effective, several adsorbents were examined (Tikki 2014;Habuda-Stanic et al 2014). Those included activated alumina (Khichar and Kumbhat 2015), calcite (Budyanto et al 2015;Turner et al 2005;Ali 2013;Dutta, and Nath 2010;Padhi and Tokunaga 2015), magnesia (Xu et al 2012;Aravind and Elango 2006), and clay (Vinati et al 2015). Additionally, Medellin-Castillo et al (2015) and Jayarathne et al (2015) examined bone char (hydroxyapatite) for F − adsorption from water.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of fluoride adsorption onto native and Mg(OH)2-amended limestone

AL-Darwish

Abu‐Sharar

2021

Appl Water Sci

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The adsorption kinetics of fluoride onto limestone (LS) and Mg(OH)2-amended LS were investigated using batch adsorption technique. Data were best fitted to second-order and Elovich models. The Mg(OH)2-ameded LS showed substantial increases in F− adsorption relative to native LS. Similarity of ionic radii and charge of both F− and OH− were hypothesized to be the major cause of such increases. The OH− functional group of the surface Mg(OH)2 could be exchanged by aqueous F− through surface complexation (ligand exchange). No background effect of naturally occurring anions in F−-rich groundwater on adsorption capacity of Mg(OH)2-amended LS. The results reveal that the Mg(OH)2-amended LS can be environmentally safe and economical for F− removal.

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Adsorption and precipitation of fluoride on calcite nanoparticles: A spectroscopic study

Cited by 73 publications

References 22 publications

Precipitation Methods Using Calcium-Containing Ores for Fluoride Removal in Wastewater

Precipitation Methods Using Calcium-Containing Ores for Fluoride Removal in Wastewater

Bimodal Ultrasound and X-ray Bioimaging Properties of Particulate Calcium Fluoride Biomaterial

Kinetics of fluoride adsorption onto native and Mg(OH)2-amended limestone

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