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 by hydrothermally modified limestone powder using phosphoric acid ... Fluoride removal by hydrothermally modified limestone powder using phosphoric acid. Robin Dutta. 2016, Journal of Environmental Chemical Engineering. See Full PDF Download PDF.
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 ...
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).
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 ...
A Limestone Reactor for Fluoride Removal from Wastewaters. E. Reardon Yan-xin Wang. Environmental Science, Chemistry. 2000; 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.
adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A
] 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
A two-column limestone reactor has been designed to reduce fluoride concentrations from wastewaters to below the maximum contaminant level (MCL limit) of 4 …
In this study, fluoride removal by crushed limestone (99% pure calcite) was investigated by batch studies and surface-sensitive techniques from solutions with fluoride …
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 ...
Plan and track work Code Review. Manage code changes
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 ...
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.
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.
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 ...
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.. …
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 ...
Limestone has potential for fluoride removal, but its effectiveness may be limited by the initial concentration of fluoride in water. Activated granular carbon and other adsorbent …
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 …
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).
A two-column limestone reactor has been designed to reduce fluoride concentrations from wastewaters to below the maximum contaminant level (MCL limit) of 4 …
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].
From the result, a related trend was viewed for contact time and sorption efficiency of activated kaolin and limestone. The rate of fluoride removal by activated kaolin was increased from 2.15-3.82 mg F − /g and by limestone was increased from 1.65-3.25 mg F −1 /g during 10-60 min. However, there was no substantial increase in the removal ...
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 …
Cited by: 35 Fluoride Removal from Contaminated Water by . This fluoride removal efficiency was higher than with the limestone reactor of Reardon and Wang (by a further reduction of 119 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 …
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 …
Mechanism of fluoride removal by phosphoric acid-enhanced limestone: equilibrium and kinetics of fluoride sorption
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 …