role of calcite in fluoride removal

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Role of Bioremediation as a Low-Cost Adsorbent for …

 · Turner BD, Binning P, Stipp SLS (2005) Fluoride removal by calcite: evidence for fluorite precipitation and surface adsorption. Environ Sci Technol 39(24):9561–9568 CrossRef Google Scholar Vivek Vardhan CM, Karthikeyan J (2011) Removal of fluoride from water using low cost materials.

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Minerals | Free Full-Text | Precipitation Methods Using …

The fluoride concentration could decrease from 310 mg/L to approximately 14.5 mg/L at the calcite dosage of 12 g/L, with the fluoride removal rate of 95.32%. This is different from the results obtained in simulated system, where the fluoride concentration could reduce to less than 12 mg/L at the calcite dosage of 2 g/L and even to approximately 8 mg/L at the calcite dosage of 10 g/L.

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Fluoride Removal by Calcite: Evidence for Fluorite …

Fluoride Removal by Calcite: Evidence for Fluorite Precipitation and Surface Adsorption

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Read Download Fluoride Removal From Groundwater By …

 · Read Online Fluoride Removal From Groundwater By Adsorption Technology and Download Fluoride Removal From Groundwater By Adsorption Technology book full in PDF formats. Ground water is main source of water supply in most rural communities in Africa. It ...

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Effective removal of fluoride and phosphate pollution …

 · The removal of fluoride from environmental surface water and groundwater is an important environmental issue in Tunisia. Notably, Tunisia also faces a shortfall in reservoir capacity due to the buildup of sediment containing calcium carbonate. Dicalcium phosphate dihydrate (DCPD, CaHPO4·2H2O) reacts effectively with fluoride to form stable fluorapatite (FAp, Ca10(PO4)6F2), and …

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Model experiments with CaO, MgO and calcinated …

Abstract Fluoride removal was studied from saline waters using CaO, MgO and calcined natural dolomite (all fired at 1273 K), as an alternative for lime slurry neutralization process. Fluoride in the form of HF was added to sea water, saline groundwater or distilled water from 50 to 158 mg dm −3 . The amount of added CaO, MgO and CaO·MgO varied from 80 to 560 mg dm −3 . Concentrations of ...

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Precipitation and adsorption during fluoride removal from …

In this paper, removal of fluoride from model solutions and a Tunisian groundwater sample was performed using calcite particles in the presence of acetic acid in batch experiments. After 1 h decantation, dead-end microfiltration was further used to retain …

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Effects of on the Removal of Fluoride from Wastewater by Calcite

Optimal fluoride removal occurs at pCO2∼10−0.52 [30% (mol% CO 2 )] with 96% of the initial 2,000 mg=L fluoride load removed in less than 80 min witha stirring rateof 300revolutionsper minute.

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Fluoride Removal from Contaminated Water by Limestone Reactor and Phosphate Rock …

examines the known role of citrate ion to induce fluoride ion to co-precipitate in calcite, and evaluates its effectiveness to improve the passive, two-column reactor of Reardon and Wang to attain drinking water quality fluoride concentrations.

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Impact of phosphate on fluoride removal by calcite.

Fluoride can be removed from wastewater by addition of calcite. However, fluoride is often found in complex mixtures where other contaminants can affect the removal process. Batch experiments were used to determine the impact of phosphate (PO43-) on the ...

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Vol. 4, Issue 9, September 2015 Fluoride Removal from Water By …

The 25.68% of fluoride removal was obtained in first 30 minutes, whereas 47.94% removal occurred within equilibrium time of 24 hours at pH of 6.0 to 5.5 mg/l of initial fluoride concentration.

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FLUORIDE REMOVAL FROM AQUEOUS SOLUTIONS BY ZINC …

Fluoride 53(3 Pt 2):531-541 July-September 2020 Fluoride removal from aqueous solutions by zinc oxide nanoparticles Mahvi, Rahdar, Igwegbe, Rahdar, Ahmadi 532 532 [Now published in full after the initial publication as an Epub ahead of print on Oct 7, 2020

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Effects of pCO2 on the Removal of Fluoride from …

AbstractFree-drift batch reactor experiments using calcite (limestone, CaCO3) were used to study fluoride removal through precipitation as fluorite (CaF2) from solutions with concentrations reflective of an industrially contaminated site. The influence of CO2 partial pressure (pCO2), stirring rate, and fluoride concentration were investigated in this paper. Equilibrium modeling shows that in ...

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Fluoride removal by induced crystallization using …

 · It has been reported that calcite can be used for fluoride removal via the precipitation of CaF 2 and that the presence of phosphate will decrease fluoride removal via competitive binding with calcium . This type of competitive binding was thought to contribute to the

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Evaluation of Effect of Brushite-Calcite and Two …

Evaluation of Effect of Brushite-Calcite and Two Indigenous Herbs in Removal of Fluoride from Water. (PMID:27504417 PMCID:PMC4963777) Abstract Citations Related Articles Data BioEntities External Links '' '' Ramesh MV 1, '' '' Naveenkumar PG 2, '' '' ...

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A critical study on efficiency of different materials for …

 · Turner BD, Binning P, Stipp SLS. Fluoride removal by calcite: evidence for fluorite precipitation and surface adsorption. Environ Sci Technol. 2005; 39:9561–9568. doi: 10.1021/es0505090. [] [] [Google Scholar] Islam M, Patel RK. Evaluation of removal efficiency

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Fluoride removal by calcite: evidence for fluorite precipitation and …

 · When HCl-cleaned calcite was used, the observed fluoride removed was similar to that of raw crushed limestone, but constitutes 5.1±1.2% of the available number of adsorption sites. These results compare to a removal of ~0.4% determined by Fan et al. (6) 2-8

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Minerals | Free Full-Text | Precipitation Methods Using …

As calcite is insoluble in water, fluoride cannot be effectively removed by adding water directly under neutral conditions. A certain amount of acid is necessary to dissolve calcite in order to produce Ca 2+, which could precipitate fluoride ions. CO 2 was produced during the dissolution process and was dissolved in water.

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Precipitation and adsorption during fluoride removal …

The increase in fluoride removal with acetic acid was mainly attributed to the renewal of the area available for adsorption on the calcite particles. At the fluoride concentration of 50 mg L −1, the removal efficiency was equal to 9.5% without acid and 94.3% with the addition of 0.1 M acetic acid.

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Impact of phosphate on fluoride removal by calcite

Title Impact of phosphate on fluoride removal by calcite Creator Turner, Brett D.; Binning, Philip J.; Sloan, Scott W.

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Fluoride removal from waters using geomaterials | Wat …

By: Xanxin Wang, Ph.D., China University of Geosciences (Wuhan) Visiting professor at the University of Waterloo (1998-1999) The element fluorine, ranking thirteenth in abundance in the Earth''s Crust, is used by higher life forms in the structure of bones and teeth. The importance of fluoride in forming human teeth and the role of fluoride intake from drinking water in

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Study on the fluoride removal characteristics of mineral …

metals. In case of fluoride ion, mechanism of its removal may be quite different as compared to positively charged metal ions. A strong affinity of fluoride for calcium that is available in rock phosphate mineral as calcite, can play an effective role in fluoride

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FLUORIDE REMOVAL FROM AQUEOUS SOLUTIONS BY …

Research report Fluoride 49(3 Pt 1):233-244 July-September 2016 Fluoride removal from aqueous solutions by cupricoxide nanoparticles Bazrafshan, Balarak, Panahi, Kamani, Mahvi 234 range of adsorbents, is still one of the most extensively used processes. Many

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Fluoride removal by calcite: evidence for fluorite …

Turner, BD, Binning, PJ & Stipp, SLS 2005, '' Fluoride removal by calcite: evidence for fluorite precipitation and surface adsorption '', Environmental Science and ...

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Phosphate-induced Transformation of Calcite to Fluorapatite in the Presence of Fluoride

Calcite Calcite+P Calcite+F+P Phosphate-induced Transformation of Calcite to Fluorapatite in the Presence of Fluoride A ... Prevalent F-removal technologies utilize aluminum (Al)-based sorbents that are prone to leach neuro-toxic Al in the treated water 5(PO 4 ...

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How to Remove Fluoride from Drinking Water

Degreased and alkali treated bones are effective in the removal of fluoride from initial fluoride concentration ranging from 3.5 mg fluoride/L to 10 mg fluoride/L to less than 0.2 mg fluoride/L Bone contain calcium phosphate and has a great affinity for fluoride.

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Fluoride removal by calcite: evidence for fluorite …

 · Fluoride contamination of groundwater, both anthropogenic and natural, is a major problem worldwide. In this study, fluoride removal by crushed limestone (99% pure calcite) was investigated by batch studies and surface-sensitive techniques from solutions with fluoride concentrations from 150 micromol/L (3 mg/L) to 110 mM (approximately 2100 mg/L).

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Fluoride Removal by Calcite: Evidence for Fluorite …

adshelp[at]cfa.harvard The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A

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Precipitation Methods Using Calcium-Containing Ores for Fluoride …

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.

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Impact of Phosphate on Fluoride Removal by Calcite | …

To date no studies have examined the impact of phosphate on the removal of fluoride from water using calcite, a cost-effective, readily available material commonly used as a water filter substrate. Importantly, this study provides quantitative information for environmental engineers and decision makers on the impact of phosphate on the ability of calcite to remove fluoride from contaminated water.

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[PDF] Fluoride removal by calcite: evidence for fluorite …

Fluoride contamination of groundwater, both anthropogenic and natural, is a major problem worldwide. In this study, fluoride removal by crushed limestone (99% pure calcite) was investigated by batch studies and surface-sensitive techniques from solutions with fluoride concentrations from 150 micromol/L (3 mg/L) to 110 mM (approximately 2100 mg/L). Surface-sensitive techniques, including atomic ...

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