Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Water Is Purified From Fluorine

15.03.2004


Researchers of the Kola Scientific Center, Russian Academy of Sciences, have developed an efficient method for sewage water purification from fluorine ions. Fine purification of water can be achieved through utilisation of sorbents containing titanium. In addition, the method solves the problem of recycling spent sorbents saturated with fluorine.



The majority of contemporary toothpastes contain sodium fluoride as a fluoridiser agent to reinforce enamel. In the natural environment, this substance is found in the form of transparent deep cherry-coloured crystals called williomits after a French traveller, whose collection of minerals from Guinea was the first to reveal this crystal.

Williomits get washed out, this causing the fluorine ions’ presence in the water. Normally, their concentration should not exceed 1.4 milligram per litre of water, however, the fluorine content should be twice lower that that in the water intended for fish industry activity: the fish accumulate fluorine in the organism and then it is consumed by people. The substance which in small amounts is contained in the toothpaste and strengthens the teeth has become the reason for serious problems in Kola Peninsula and other regions, where mining enterprises work intensely to process ores containing williomits.


This results in millions of cubic metres of sewage with high content of fluorine ions, their concentration exceeding the maximum allowable concentration by ten times, and this is very dangerous for human health. Abundant fluorine content in the organism may cause the fluorosis disease. As a result, the enamel decays, white spots appear on the enamel and turn yellow as time passes. In addition, abundant fluorine inhibits some enzymes’ action in the organism. Poison is curative only in small dozes.

So far, there has been no inexpensive and efficient technology for water purification from fluorine ions. Researchers from the Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral (Kola Scientific Center, Russian Academy of Sciences) suggested that various titanium compounds should be used as sorbents: titanyl hydroxides or sulphates, which tightly bind fluoride ions.

For example, when processing the mineral which contains titanium, it is easy to get titanyl sulphate that can be efficiently used to purify water from ions of fluoride. This compound is added to the sewage water while mixing, it dissolves rather easily, and then, as a result of hydrolysis, it turns into the loose deposit. It is the deposit that plays the role of sorbent in purification of water from ions of fluoride.

After such processing, sorbents containing fluorine in the form of deposit can be simply filtered. This method provides for fine purification of water, decreasing the flurine ion content down to 0.5-0.6 milligram per liter, which poses no threat to human health. For example, if the water contains 10 milligrams of fluorine ions per liter, then processing of one liter of such water would require 80 milligrams of titanyl sulphate.

The new water purification method also solves the problem of disposal of spent sorbents with fluorine ions contained in them. Previously, fluorine saturated sorbents, accumulated, and fluorine penetrated the soil and contaminated the environment. Under the new method, spent solid sorbents may be processed with sulphuric acid, thus getting valuable hydrogen fluoride and fresh portions of water soluble titanyl sulphate, which can be reused. Therefore, the method suggested by the researchers will allow to purify water from fluorine, to obtain a valuable chemical product and to save sorbent.

Sergey Komarov | alfa
Further information:
http://www.informnauka.ru

More articles from Ecology, The Environment and Conservation:

nachricht Urban growth causes more biodiversity loss outside of cities
10.12.2019 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Wie ganze Ökosysteme langfristig auf die Erderwärmung reagieren
10.12.2019 | Universität Wien

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Cheers! Maxwell's electromagnetism extended to smaller scales

More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?

It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

Im Focus: Electronic map reveals 'rules of the road' in superconductor

Band structure map exposes iron selenide's enigmatic electronic signature

Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Weizmann physicists image electrons flowing like water

12.12.2019 | Physics and Astronomy

Revealing the physics of the Sun with Parker Solar Probe

12.12.2019 | Physics and Astronomy

New technique to determine protein structures may solve biomedical puzzles

12.12.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>