Published
by Leonardo Zanata, Professor at Faculdades Oswaldo Cruz
Hello everyone!
Here in Brazil, São Paulo State and near regions some wells (mostly tube wells) which are 80 to 400 m deep has high concentration of Fluoride (F-), between 3 to 15 mg/l of F-, specially in the drought periods, when the water replacement in the aquifers is low.
So, what can be the solution? Reverse Osmosis? Electrode-ionization? Ion Exchange?
The solution that we use is use of low electric current electrolysis for capturing the fluoride in the electrode.We found this is a quick and cheap process for treating the fluoride water.
But I would like to hear from water treatment fellows, if they have other solutions which are quicker and economical.
The National Ground Water Association issued a best suggested practices document on this specific topic in December 2009. Contact me at kmccray@ngwa.org to request a copy.
Removal of fluoride from water is difficult. Most home point-of-use treatment systems that are installed at single faucets use activated carbon filtration, which does not remove the fluoride. Reverse osmosis point-of-use devices can effectively remove fluoride, although the amount may vary given individual circumstances. For a home point-of-use device to claim a reduction in fluoride, it must meet National Sanitation Foundation (NSF) Standard 58 criteria for fluoride removal. Standard 58 requires that a device must achieve a 1.5 milligrams per liter (mg/L) concentration in the product water if the original concentration was 8.0 mg/L, or approximately 80 percent removal. This percentage removal may not be consistent at lower concentrations of fluoride. Check with the manufacturer of the individual product for specific product information. Fluoride is not released from water when it is boiled or frozen. One exception would be a water distillation system. These systems heat water to the boiling point and then collect water vapor as it evaporates. Water distillation systems are typically used in laboratories. For home use, these systems can be expensive and may present safety and maintenance concerns.
RO will be the best technology - it removes 90-95% of the Flouride.
Residual Fluoride can be monitored by modern on-line Sensors, without chemicals added to the sample water, easy and with low investment cost & operation expenses.
http://www.whydontyoutrythis.com/2013/06/the-tulsi-plant-can-be-used-to-remove-fluoride-from-drinking-water.html An exciting and new water treatment breakthrough has been announced that will now make the removal of fluoride from the drinking water supplies of the world’s poorest people more affordable than ever. The Tulsi Plant Can Be Used To Remove Fluoride From Drinking Water - Tulsi LeavesResearchers from Rajasthan University in India have discovered that the Tulsi plant, also known as Holy Basil, can be used to significantly reduce the amount of fluoride in drinking water. At present, the most reliable methods used to remove excessive fluoride from drinking water are either too expensive or not suitable for the environments where they are needed most. The method discovered by researchers from Rajasthan University is safe, cheap and readily available, making it an ideal alternative for communities who can’t afford to use the more advanced techniques of removing fluoride that are readily available in the West. An experiment was conducted in the Yellareddyguda village of Narketpally Mandal. The researchers soaked 75mg of Tulsi leaves in 100ml of water that contained 7.4 parts per million of fluoride in the water. After only soaking the Tulsi leaves for eight hours, it was discovered that the level of fluoride in the water was reduced from 7.4 parts per million, to only 1.1 parts per million. At present, the World Health Organization recommends that the safe level of fluoride in drinking water is between 0.5 to 1 parts per million. The dangers of drinking water that contains high levels of fluoride are well known. Some of the known side effects of drinking water that contains fluoride are dental fluorosis, reduced intelligence in children and a damaged nervous system. This new water treatment option could now provide the world’s poorest people an opportunity to remove excessive fluoride from their drinking water supplies. However, more research is still needed to identify and validate the effectiveness of using Tulasi leaves as a means of removing fluoride from drinking water supplies. Considering the cost-prohibitive nature of other more reliable water treatment techniques, if the Tulsi plant is conclusively proven to be effective in removing fluoride from drinking water, then we may witness a revolution in water treatment, providing options to areas where none currently exist. Source: Globalist Report Read More: http://www.whydontyoutrythis.com/2013/06/the-tulsi-plant-can-be-used-to-remove-fluoride-from-drinking-water.html | Follow us on Facebook: http://www.facebook.com/whydontyoutrythis
Possible solutions for removing fluoride out of well water
Fluorinecomponds can partly be precipitaded with lime. Because, however, material is required for the coagulation, ion exchangers are often a better soluitons. In addition, a water treatment by adsorption, distillation or reverse osmosis is also possible.
Capacitive Deionization: about .5 to .8 kilowatt hour per cubic meter, 95% removal and depending upon other salts 90 to 95% recovery of the water.
R.O. : about 75% recovery at about 2 Kilowatt hours per cubic meter, any calcium in the water causes calcium flouride scaling so must be cautious of this and use antiscalants
Alumina: absorptive media that requires regeneration and often problematic
Precipitation with lime: large sludge problem and requires large amount of lime to remove
Reverse osmosis (RO) represents a reverse of normal osmotic processes. It relies on pressure and a semi-permeable membrane to remove contaminants from water. RO can remove between 90 and 95% of fluoride (depending on the efficiency of the system and depending on how well the system is maintained). Contaminants are trapped by the RO membrane and flushed away in the waste water. The process requires between 2 and 4 gallons of water to produce 1 gallon of RO water (depending on the quality of the water and the efficiency of the RO unit). Source water with an abundance of contaminants (including hard water) can reduce the efficiency of an RO system and it can shorten the life of the membrane.
Similar to distillation, RO has a good track record for removing almost everything from water. Quality RO systems include pre-filters to remove VOCs (volatile organic compounds), heavy metals, hard water minerals, and other contaminants that reduce the life of RO membranes. And similar to distillation, RO leaves water empty and lifeless. The addition of salts and the re-introduction of life force are necessary to bring RO water back to energetic compatibility with the human body.