The effects of solution pH and temperature on the adsorption of fluoride onto bone char made from cattle bones were investigated in this work. It was found that the maximum adsorption took place at pH 3 and the adsorption capacity decreased nearly 20 times augmenting the pH from 3 to 12. This behavior was attributed to the electrostatic interactions between the surface of bone char and the fluoride ions in solution. The adsorption capacity was not influenced by temperature in the range from 15 to 35 °C. A comparison of fluoride adsorption capacities among several adsorbents revealed that the adsorption capacity of the bone char was 2.8 and 36 times greater than those of a commercial activated alumina (F-1) and a commercial activated carbon (F-400). The adsorption capacity is considerably dependent upon the physicochemical properties of the bone char surface and the solution pH.

/pdf/adsorption-of-fluoride-from-water-solution-on-bone-char-2xjff2bkrx.pdf

Adsorption of Fluoride from Water Solution on Bone Char

http://edge.rit.edu/content/P13418/public/Reference%20Documents/Fluoride%20Removal/Review%20of%20fluoride%20removal%20from%20drinking%20water.pdf

Review of fluoride removal from drinking water.

This paper presents the synthesis of iron(III)−aluminum(III) mixed oxide with some of its physicochemical characteristics and fluoride adsorption behavior thereon. Results showed that the optimum i...

Adsorption of Fluoride from Aqueous Solution by a Synthetic Iron(III)−Aluminum(III) Mixed Oxide

Removal of fluoride from aqueous solution and groundwater by wheat straw, sawdust and activated bagasse carbon of sugarcane

Adsorption of fluoride by hydrous iron(III)-tin(IV) bimetal mixed oxide from the aqueous solutions

The study assesses the suitability of inexpensive leaf adsorbents to effectively remediate fluoride-contaminated water. The efficiency of the sorption of fluoride ion is affected by pH, contact time, adsorbent dose, type and size of adsorbents and initial fluoride ion concentration. The adsorption equilibrium is well correlated by Freundlich and Langmuir models. Treated leaf powder was studied at various pHs (2, 4, 6 and 8) with a series of aqueous solutions containing 2, 3, 5, 6, 8, 10, 12, and 15 mg F/l. At the highest F-ion concentration (15 mg/l), the F-ion level in the effluent gradually decreased to 0
mg/l within 180 min at 29 +or-.5 degrees C when the dose of adsorbent is 10 g/l in a sample of 50 ml volume. With lower F- ion concentrations (2 mg/l) in the feed solutions the fluoride ion concentration steadily decreased reaching 0 mg/l after 150 min. Langmuir isotherm fits well for defluoridation of water using leaf powder.

/pdf/defluoridation-of-water-using-inexpensive-adsorbents-2gaz1dmurq.pdf

Defluoridation of water using inexpensive adsorbents

Column kinetics for fluoride ion removal could be described more adequately by the Lobenstein model than by conventionally used models. This model can be used in a linearized form. Use of this model minimizes the error resulting from use of conventional models, especially at lower or higher time periods of the breakthrough curve.

https://journals.sagepub.com/doi/pdf/10.1260/026361704323151006

V.S. Jamode

Papers

Defluoridation of water using inexpensive adsorbents

Adsorption Kinetics of Defluoridation Using Low-Cost Adsorbents