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Friday, August 22, 2014

 

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 R/O Tab

Reverse Osmosis

Reverse osmosis is widely considered as the best choice for the reduction of fluoride.

Highest Fluoride Removal

Using a cellulose acetate/cellulose triacetate (CA/CTA) membrane, fluoride reduction rates of 80-90 percent are achievable when the pH is in the 4-8.5 range.

Thin Film Composite membranes (TFC - right) are now most commonly used in high quality systems and will yield an even higher fluoride removal rate (up to 95 percent) in the 3-11 pH range. However, in the real world most domestic R/O systems usually achieve between 80 to 90% fluoride removal.

Both CA/CTA and TFC membranes should be operated at a minimum membrane pressure differential of at least 30 psi.

Fluoride Limitations

While R/O is considered the most efficient and cost effective filtration technology for removing fluoride - plus the widest possible range of other contaminants - even the highest quality membranes only remove between 80 to 95%.

Also, over time fluoride removal rates will also deteriorate. Unless reqularly maintained fluoride removal in an R/O system can drop below 80%. Lower quality R/O systems made in China, or those using direct flow (tank free) technology, often can only remove 80 to 85% - sometimes less.

In order to remove more than 99% of fluoride consistently a commercial grade R/O system with multiple membranes is required. Alternatively, another type of R/O system usig more than just membrane techology is required.

 

Fluoride - Health Concerns?

For over fifty years water fluoridation has been an accepted part of the public health program in many western countries. However, there is a significant and growing body of evidence indicating that the original studies used to support the introduction of fluoridation may have been deeply flawed at best and corrupted and compromised science at worst.

“Over the past ten years a large body of peer-reviewed science has raised concerns that fluoride may present unreasonable health risks, particularly among children, at levels routinely added to tap water in American cities.”

US ENVIRONMENTAL WORKING GROUP - July, 2005

Questions about fluoride effectiveness for cavity prevention is also being compounded by the fact that fifty years of real world research has discovered enough evidence to at least question the effect of long-term exposure to fluoride, particularly for infants and children. Some research suggests it may have deleterious effects on;

  • Thyroid regulation
  • Bone development
  • Brain function and IQ
  • Kidney function
  • Gene expression
  • Cell regulation

Due to these concerns, about what is essentially a compulsory form of public medication, many alternative healthcare professionals, researchers and consumers are demanding fluoride free drinking water. 

The urgent consideration is total fluoride ingestion -- how much fluoride are people taking into their bodies from fluoride air pollution, from soil, from water, from products processed in fluoridated water, from pharmaceuticals, pesticides, herbicides and so forth?."

Ralph Nader - Consumer Advocate

Exploiting Fears

Unfortunately, these very real concerns have been exploited by some water filter resellers making misleading claims about the ability of certain types of water filtration media, usually the ones they sell, to remove fluoride.

When fluoride is added to drinking water it is in ionic form and dissolves entirely. This means it cannot be effectively removed using standard carbon, ultra or even new Nano filtration technology. In fact, fluoride is one of the hardest things to completely remove from water, even with Reverse Osmosis - a proven and well tested technology.

Below we examine several popular 'alternative' technologies currently being sold with fluoride removal claims as their key selling feature.

 

Fluoride Ion

Sodium Fluoride - NaF

 Ionizer Tab

Electrical Water Ionizers

Some electrical water ionizers claim to remove fluoride. However, this relatively ancient 1960's technology uses 'water electrolysis' - a process that is scientifically incapable of removing fluoride.

The only fluoride removal capability water ionizers offer is through the use of pre-filters using Activated Alumina or Bone Char (both shown to be ineffective). Another alternative is Reverse Osmosis however this raises several important issues.

Revese Osmosis & Ionizer Issues  

Reverse Osmosis removes minerals but these are crticial to the electrolysis process. Minerals are the primary conductor of electrical charge - this is why distilled water cannot conduct an electrical current.  Without minerals ionziers simply cannot 'ionize'.

To work around this problem Ionizers have been using a remineralisng cartridge. However, it is not clear, as there is no data, as to whether the minerals replaced are in high enough concentrations to allow sufficient ionization (the actual purpose of the device) to occur.

Another more critical issue that we believe has been completely missed by electrical water ionizer resellers and consumers alike.

Heavy Metals

Electrical water ionizers were never designed to remove fluoride and the addition of Reverse Osmosis is a relatively recent development. So, what's the problem?

Reverse Osmosis water is notoriously aggressive. Water requires minerals to maintain stability and when it has been stripped it will take them from the surrounding environment. If demineralised water cannot find minerals it will take heavy metals instead. And here lies the potential problem.

Electrical Ionizers all use heavy metal plate electrodes, the heart of the device. If water is still 'aggressive' after R/O pre-treatment could the heavy metal electrodes be slowly leaching metals?  Unfortunately, there is not data available as these combined Ionzier R/O systems have never been subjected to the certification testing that would determine this.

Importantly, we found fluoride removal claims appear to only be made by ionizer resellers and not by the original equipment manufacturers. Caveat Emptor?

Summary

We debated whether electrical ionizers should be included in this review given they are not capable on their own of flouride removal, however. We have been approached by many consumers who believe they may have been misled into thinking their 'water ionizer' removes fluoride.

The bottom line is that electrical ionizers, unless using Reverse Osmosis pre-filtration, will not remove fluoride to any great degree. And, if they are using R/O pre-filtration then fluoride removal rates will vary depending on the quality of the R/O system being used.

 Alumina Tab

Activated Alumina

A quick internet search will reveal Activated Alumina is being heavily promoted as an effective fluoride removal media for drinking water. While some impressive claims can be found it is important to note that these are being made exclusively by small, and almost exclusively online, water filter resellers.

We can find no manufacturers of household water filter offering Activated Alumina cartridges or making similar fluoride claims. There must be a good reason why the world's leading filter manufacturers do not sell these cartridges?.

Yes, there is. The simple fact is that fluoride removal claims for Activated Alumina DO NOT stand up to scrutiny.

The Facts

In commercial treatment plants Activated Alumina has been shown to remove fluoride at rates of up to 95%. However, in order to achieve these high removal rates several key factors need to present;

  • Low pH
    Peak removal efficiency for flouride, up to 95%, requires water pH to be below 6.0 and ideally below 5.5.  If water pH is above 6.5 removal drops to below 70%. At pH 7.5, which is the average range for municipal water supplies, removal drops to below 50%.  

Of course, these removal rates also require two other key factors;

  • Low Flow
    To achieve even the above modest fluoride removal rates water needs extensive 'residence' or contact time with the Activated Alumina media. In a standard 2.5 x 10" filter cartridge this means flow rates need to be less than 250 ml per minute - 1 litre every four minutes.  If flow is increased to an average of 1.5 litres per minute then fluoride removal at a pH of 7.5 drops to less than 30%.
     
  • Frequent Replacement
    In commercial situations when Activated Alumina is fully spent it is regenerated. This entails flushing the media with sulfuric acid. Naturally, in a domestic water filter this is just not possible.

    Because it cannot be regenerated an Activated Alumina cartridge would need to be replaced every 250 litres or so to achieve even the modest results above.

The highest fluoride removal rates quoted for Activated Alumina could never be achieved in a domestic setting.

Whole Home Fluoride Removal? 

Despite this some companies actually claim Activated Alumina is an effective technology for whole of home flouride removal. Aside from the fact that fluoride removal is only needed for drinking water, in order to achieve any meaningful results would require up to twenty large 4.5 x 20" filter housings packed with Activated Alumina media. This would be impossible to install and maintain even in a commercial setting let alone a domestic one.

Any claims being made for Activated Alumina technology in whole of home filter applications should be dismissed for what they are - fraudulent.

Summary 

Activated Alumina is ideal for fluoride removal in commercial waste water treatment systems where water pH can be lowered to below 5.5 and where volume of media used is not limited by cartridge size.

In domestic water filter systems Activated Alumina achieve less than 50% removal rates, often far less.  Activated Alumina is not a suitable Point Of Use technology for fluoride removal on municipal water sources.

 

 Bone Char Tab

Animal Bones - Bone CharBone Char 

Like Activated Alumina cartridges Bone Char has also been widely promoted by smaller water filter resellers as being effective for fluoride removal.

What is Bone Char?

Like the name implies, Bone Char is actually the remains of animal bones that have been crushed, exposed to high furnace temperatures and carbonised.

Bone charcoal contains a carbon structure while supporting a porous hydroxyapatite matrix (a calcium phosphate hydroxide in crystalline form which is rich in surface ions that can be readily replaced by fluoride ions). Adsorption and ion exchange are the mechanism for fluoride reduction.

Is it effective?

The effectiveness of Bone Char is similar that of Activated Alumina. It requires a  low pH (again, below 6.5 is recommended), low flow rates and frequent replacement of cartridges.

While new Bone Char cartridges are claimed to reduce fluoride by up to 90%, in controlled laboratory tests we found that after only 50 litres (10 gallons) fluoride removal dropped from 80% to 50%. And, after just 100 litres fluoride removal was only 25%.

This means in order to remove fluoride at anywhere near an effective rate a Bone Char cartridge would need to be replaced at least every week. This is neither practical or cost effective.

Industry Notice

In published advice from the independent Water Quality Association examining Bone Char and  Activated Alumina they made the following comment:

"Because of the diverse influent water chemistries and product designs, water analysis tests to confirm effective treatment by any of the POE (Point of Entry/Whole Home) units for fluoride removal is recommended. Only POU (Point of Use) units tested and certified for fluoride reduction are recommended to be used for such purposes."

WQA - Technical Advice Bulletin

In other words, as early as 2004 WQA recognised that fluoride removal claims made for Bone Char require confirmation by scientific testing and certification. We also note that as of 2012 there were no Bone Char filter cartridges registered or certified with either WQA or NSF.

Whole Home Fluoride Removal

In order to be effective at removing fluoride from the entire home water supply Bone Char media requires a pH below 6.5 (the lower the better) and a contact time of around 20 minutes. This would require the installation of a filtraton system, allowing for a flow rate of at least 20 litres per minute (most whole of home systems offer 60 litres per miniute), of approximately 200 liters worth of Bone Char media.  With associated equipment the installation footprint would be the size of a small car.

Again, like the claims made for Activated Aluminawhole of home fluoride removal claims using Bone Char are equally misleading. 

Summary 

Bone Char is ideal for fluoride removal in third world situations where fluoride presents a serious health risk at greater than 5ppm. In these situations contact time can be well in excess of 60 minutes and the volume of media used is not limited by cartridge size.

In domestic Point of Use filter systems for drinking water Bone Char achieves less than 50% removal rates, often far less, and requires cartridge replacement every 100 litres. Bone Char is simply not a suitable technology for fluoride removal for use on municipal water sources.

 

Is Fluoride Free Water Possible?

As can be seen, there is a wide range of fluoride removal technologies. Many do not live up to the claims being made for them and are just not suitable for use in a domestic situation.  Even the best fluoride removal technology - Reverse Osmosis - achieves only 95% removal rates under optimal conditions.

In addition, R/O produces water that is devoid of all minerals. Such water has been shown to be not ideal for long-term health.

Is there a way to produce a healthier water with better fluoride removal rates?  Yes. We believe there is.

Introducing Wellness® Fluoride Free R/O

Wellness® has been working for several years on developing a new type of domestic Revese Osmosis system. A filter specifically designed to remove greater than 99.95% - essentially Fluoride Free - water.  But, we wanted more.

We wanted to produce a water that was more than just fluoride free.  Our water has to be remineralised and naturally energised - like all our flagship drinking water filters have been doing for over 10 years..

After years of testing and developing we are proud to announce the release of the Series 5 + R/O multi-stage filtration and remineralisation system.

Click here to find out more....

 

All prices are in AUD | Wellness Pty Ltd | ABN 47 078 340 315 | All Rights Reserved.
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Drinking Water and Whole Home Filter Systems | Reverse Osmosis | Wellness LivingWater
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