Fluoride removal from potable water supplies

Sollo Jr., F.W.; Larson, Thurston E.; Mueller, Henry F.

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https://hdl.handle.net/2142/90268 Copy

Description

Title

Fluoride removal from potable water supplies

Author(s)

• Sollo Jr., F.W.
• Larson, Thurston E.
• Mueller, Henry F.

Contributor(s)

University of Illinois at Urbana-Champaign

Issue Date

1978-09

Keyword(s)

• Water resource development
• Water resource development--Illinois
• Public health
• Fluorides
• Coagulation
• Flocculation
• Alum
• Fluorapatite
• Magnesium hydroxide
• Water softening
• Adsorption
• Activated carbon
• Coagulant aid

Geographic Coverage

Illinois (state)

Abstract

The objective of this project was to determine whether or not the fluoride level in waters with moderate fluoride content (2 to 10 mg/l) could be reduced to acceptable levels by chemical treatment. The optimum concentration for dental health is from 1.1 to 1.8 mg/l. A variety of methods for the removal of fluoride have been reported in the literature. In this study, we compared the methods which appeared to have some possibility of success. Coagulation with alum at pH levels of 6.2 to 6-4 was one of the more effective methods tested. Fluoride was also found to be adsorbed by magnesium hydroxide. This occurs in the softening process with magnesium-containing waters, and could be increased by adding both magnesium salts and lime. The formation of fluorapatite by the reaction of fluoride with phosphoric acid and lime was found to be very effective for the removal of fluoride. Flocculation with iron salts was found to be of little benefit in the removal of fluoride. The fluoride removed was from 2 to 10 percent of the initial concentration. Activated charcoal was tested without any appreciable success. Polyelectrolytes, in general, did not remove fluoride, but were very helpful in obtaining good clarification for some processes and thereby aided in fluoride removal.

Publisher

University of Illinois at Urbana-Champaign. Water Resources Center

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/90268

Sponsor(s)/Grant Number(s)

• U.S. Department of the Interior
• U.S. Geological Survey

Copyright and License Information

Copyright 1978 held by F.W. Sollo, Jr., Thurston E. Larson, Henry F. Mueller

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