Fluoride removal from water by lime-sludge waste
Fluoride removal was achieved from initial 10 mg/L to less than 1 mg/L in 30 min. The initially rapid fluoride removal slowed down gradually to reach equilibrium in about 30 min as expected. Such dependence of fluoride removal on initial [F–]0 and contact time was reported for other adsorbents [36,41,47].
Fluoride Removal from Contaminated Water by …
fluoride concentration from up to 150 mg/L to below the maximum contaminant level (4 mg/L) at the residence time of 4 h. When the residence time was 24 h, fluoride concentration was reduced to below the drinking water standard (1.5 mg/L). This fluoride removal efficiency was higher than with the limestone reactor of Reardon and Wang (by a further
A Limestone Reactor for Fluoride Removal from Wastewaters
A two-column limestone reactor has been designed to reduce fluoride concentrations from wastewaters to below the maximum contaminant level (MCL limit) of 4 …
A limestone reactor for fluoride removal from wastewaters
Gogoi, S.; Dutta, R.K. 2016: Mechanism of fluoride removal by phosphoric acid-enhanced limestone: equilibrium and kinetics of fluoride sorption Desalination and Water Treatment 57(15): 6838-6851 Rodriguez, M.G.; Martinez, S.A.D. 2005: Removal of Cr(VI) from wastewaters in a tubular electrochemical reactor Journal of Environmental Science and ...
Field Trial of Fluoride Removal by Phosphoric Acid …
This paper describes the results of a field trial of our recently reported technique of fluoride removal from groundwater having potential for rural application in developing countries. The …
Mechanism of fluoride removal by phosphoric acid-enhanced limestone
With a fourfold increase in the selective fluoride removal capacity of limestone, to 4.38 mg/g, phosphoric acid (PA)-enhanced limestone has been found to be a competent adsorbent material for fluoride removal. The PA-enhanced limestone has been characterized and its fluoride sorption has been studied using various models. The removal of ...
Limestone as a sustainable remediation option for water …
This study introduces the use of a waste by-product from wet limestone flue gas desulfurization as a potential material for fluoride removal. Systematic laboratory-scale …
Fluoride Removal From Water Using Crushed Limestone: …
This document discusses a study on using crushed limestone to remove fluoride from water. The researchers examined using acetic acid and citric acid to pre-treat the fluoride water before treatment with crushed limestone. This was found to significantly improve fluoride removal by increasing the calcium ion concentration through dissolution of calcite in the limestone. Batch …
fluoride removal crushed limestone calcite wiki
Fluoride removal from water using crushed limestone 2 calcium chloride CaCl 2 and calcium sulphate CaSO 4 have already been tried for fluoride removal 33. Calcium chloride and … اقرأ أكثر
Mechanism of fluoride removal by phosphoric acid-enhanced limestone
With a fourfold increase in the selective fluoride removal capacity of limestone, to 4.38 mg/g, phosphoric acid (PA)-enhanced limestone has been found to be a competent adsorbent material for ...
A Limestone Reactor for Fluoride Removal from Wastewaters
adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A
Fluoride removal from groundwater by limestone treatment in …
Local limestone has fluoride removal abilities by phosphoric acid (PA)- local crushed Limestone treatment (PACLT), with the treated water conforming to WHO guidelines for Fluoride in drinking ...
Fluoride Removal from Contaminated Water by Limestone …
This fluoride removal efficiency was higher than with the limestone reactor of Reardon and Wang (by a further reduction of 1.19 mg/L fluoride in total) yet still lower than the predicted efficiency. One important reason of the lower fluoride removal efficiency than with prediction is that the citrate ions suppressed the precipitation of calcite.
(PDF) Fluoride removal from groundwater by limestone …
The presence of PA increases the fluoride removal capacity of limestone to 1.10 mg/g compared to 0.39 mg/g reported in its absence. The changes in fluoride removal with variation in initial PA concentration, initial fluoride concentration and the final pH have been found to be statistically significant with p < 0.05. The estimated recurring ...
Fluoride removal by hydrothermally modified limestone …
A 32% fluoride removal observed with the fresh limestone powder was found to increase to 93% with M9. The fluoride removal increased considerably on changing the adsorbents in the order: L0 < M3 < M6 < M9 as expected ( Fig. 3 A).
A study of suitability of limestone for fluoride removal by …
Limestone samples collected from different locations have been characterised using IR spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and Brunauer-Emmett-Teller analysis and correlated with their fluoride removal abilities by phosphoric acid (PA)-crushed limestone treatment (PACLT).
Fluoride removal by hydrothermally modified limestone …
Article: Fluoride removal by hydrothermally modified limestone powder using phosphoric acid. Journal of Environmental Chemical Engineering 4(1): 1040-1049 ... Chapter. Fluoride removal by hydrothermally modified limestone powder using phosphoric acid Gogoi, S.; Dutta, R.K. Journal of Environmental Chemical Engineering 4(1): 1040-1049 2016. ISSN ...
Fluoride removal by hydrothermally modified limestone …
The influence of coexisting anions on fluoride removal was low for all limestone samples and followed the order sulfate > chloride > nitrate. The surface area and total pore volume above 2.55 m² ...
Simultaneous removal of fluoride and arsenic from drinking …
Numerous groundwater wells in Mexico exceed the maximum allowable fluoride (F−) and arsenic (As) drinking water concentration requirements, posing an environmental and health risk to the population that relies solely on these wells for drinking water sources. Since encouraging results have been obtained utilizing native limestones to remove some toxic …
Fluoride removal from water using crushed limestone
NATH & DUTTA: FLUORIDE REMOVAL FROM WATER USING CRUSHED LIMESTONE 121 low cost method of fluoride removal which uses lime and alum also suffers from some disadvantages, viz., it adds toxic ...
Fluoride removal from water using crushed limestone
A study of suitability of limestone for fluoride removal by phosphoric acid-crushed limestone treatment. Rajkamal Mohan R. K. Dutta. Environmental Science. 2020; 9. Save. Precipitation and adsorption during fluoride removal from water by …
Fluoride removal by calcite: evidence for fluorite
In this study, fluoride removal by crushed limestone (99% pure calcite) was investigated by batch studies and surface-sensitive techniques from solutions with fluoride …
Fluoride removal from groundwater by limestone treatment …
Simple scrubbing and rinsing is a preferable method for regeneration of limestone as it is almost equally effective with lime or NaOH. Sorption of fluoride by calcium phosphates …
A Limestone Reactor for Fluoride Removal from Wastewaters …
A two-column limestone reactor has been designed to reduce fluoride concentrations from wastewaters to below the maximum contaminant level (MCL limit) of 4 …
Elimination of Fluoride from Water using Limestone …
] have already been used for fluoride removal (Nath and Dutta 2013). Treatment of fluoride water by limestone has been proven to be a good method for fluoride removal. It takes about 20 hrs of residential time to remove fluoride without adding any acid to the water (Reardon and Wang 2000). After addition of the acid, the time was reduced to
Fluoride removal from water using crushed limestone
The presence of PA increases the fluoride removal capacity of limestone to 1.10 mg/g compared to 0.39 mg/g reported in its absence. The changes in fluoride removal with variation in initial PA concentration, initial fluoride concentration and the final pH have been found to be statistically significant with p < 0.05.
Effects of pCO2 on the Removal of Fluoride from Wastewater by Calcite
Free-drift batch reactor experiments using calcite (limestone, CaCO 3) were used to study fluoride removal through precipitation as fluorite (CaF 2) from solutions with concentrations reflective of an industrially contaminated site.The influence of CO 2 partial pressure (pCO 2), stirring rate, and fluoride concentration were investigated in this paper.. …
Nilogon for fluoride removal from groundwater
The method can remove fluoride from a high initial concentration to zero ppm. However, as a small quantity of fluoride is required for healthy teeth and bones, the final concentration of fluoride is kept at 0.65 (±0.1) ppm with this dose of phosphoric acid. The crushed limestone bed remains active for at least four years and nine months.
Development of a limestone-based ballasted material for …
Download Citation | On Sep 1, 2024, Xiaohang Zhang and others published Development of a limestone-based ballasted material for enhanced co-removal of turbidity and fluoride from coal mine water ...
A Limestone Reactor for Fluoride Removal from Wastewaters
A two-column limestone reactor has been designed to reduce fluoride concentrations from wastewaters to below the maximum contaminant level (MCL limit) of 4 mg/L. The reactor functions by forcing calcite (CaCO3) to dissolve and fluorite (CaF2) to precipitate in the first column. The second column is not necessary to remove fluoride but is used to …