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 Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

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: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>