Activated Alumina for Fluoride Removal: The Myths and the Truths

Activated Alumina for Fluoride Removal: The Myths and the Truths

Activated alumina, also known as AA, is the only filter media designed for one purpose: to remove fluoride and arsenic from water.

What Is It?

A ceramic compound made of aluminium oxide with extreme surface-area-to-weight ratio.
Because it is designed for it, it has very high capacity for fluoride adsorption.

Most municipal water supplies add 2 ppm (parts per million) of fluoride.

AA filters are capable of reducing fluoride concentrations to below 0.1 ppm… 99% of fluoridated water level.

AA occurs naturally in its crystalline form as the mineral corundum. That's why we often refer to it as a gemstone, as it forms precious gemstones ruby and sapphire. (Wikipedia)

Activated Alumina is recommended by the Environmental Protection Agency (EPA) to effectively remove fluoride but also to remove other contaminants such as the poison thallium which has been seen to leach into the drinking water sources in roximity to mines. It is also the media of choice in the United States' largest fluoride removal plant in Andrews, Texas.

The activated alumina cartridge that we use is made in the USA. It contains a large amount of ultra high grade activated alumina which will not “powder” like cheaper versions or refillable cartridge versions.

We actually tested and replaced a number of AA medias until we found one that could satisfy the strict EU water safety guidelines)

The Ultrastream cartridge has University laboratory tested to 3500 litres at a flow rate of 1 Litre per minute, using a fluoride content of TWICE the actual max amount legislated for municipal fluoride levels.

The use of activated alumina is probably the most commonly used fluoride removal technology for large municipal treatment systems

The Question We Get Asked..

DOES ACTIVATED ALUMINA ADD ALUMINIUM TO THE WATER THAT IT TREATS?

You will see this question on the internet.
The reason the fear about this has become so persistent is largely due to sellers of reverse osmosis systems. Such is life in the world of competitive corporation marketing. who have a vested interest of course in selling their particular systems. 

The European Food Safety Authority carried out a study in 2006 to investigate these rumours. Here are their findings

The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) has been asked to evaluate the food safety aspects related to the removal of fluoride from natural mineral waters (NMWs) by filtration through a bed of activated alumina.

NMWs at source may contain levels of fluoride higher than the maximum concentration limits established for the constituents of natural mineral waters by the Commission Directive 2003/40/EEC. Removal of the fluoride is only allowed by an authorised process.

Information concerning the source and treatment of activated alumina and the filtration process conditions was provided and showed that critical steps of the proposed process are the following:

1. Testing of activated alumina filter according to the European standard applicable for leaching tests (EN 12902) [6] to ensure no impurities are leached to the water in quantities that result in concentrations exceeding the limits set in Commission Directive 2003/40/EC on the constituents of natural mineral waters, or in the absence of relevant limits in that Directive, the restrictions set in Council Directive 98/83/EC on the quality of water intended for human consumption or in national applicable legislation.

2. Initialisation procedure with alkaline or acidic chemicals to remove any impurities and fine particles before the use of the filter.

3. Regeneration procedure with appropriate chemicals to renew the capacity of the filter resulting at the same time in the removal of any possibly formed biofilm.

The report demonstrated that under optimised process conditions the release of impurities due to the use of the activated alumina, if it occurs at all, is always lower than the relevant limits set in the Directives mentioned above.

Data on the actual content of many anions and cations in various types of NMW (natural mineral waters) were provided.

In some lesser quality filtration media, an increase of the concentration after the treatment was found in some cases for aluminium (from 18 up to 86 microg/l), bromide (160 -> 280 microg/l) and boron (66 -> 550 microg/l). However, in most types of water these changes were not observed at all and the observed variations of composition before and after treatment were low.

It was demonstrated that the treatment of NWM with activated alumina is suitable for the intended purpose. Under optimized conditions the release of cations or anions from the medium during treatment is negligible and will not pose a risk to human health.

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Like every media in the UltraStream, we chose to use the highest possible grade filter after the activated alumina cartridge. This has been tested in the EU certification tests to remove 99% of any aluminium present in the water.

The UltraStream Advantage: Always Up To Date
Because we are committed to keeping the UltraStream as the best and most efficient water filter available, we've designed it in such a way that every time you order a filter replacement, you receive the most up to date filter technology, investigated, tried and tested. Your UltraStream never becomes out of date.