Good Thinking

HTI's revolutionary forward osmosis filtration system

HTI's revolutionary forward osmosis filtration system
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US special forces using the HTI expedition
US special forces using the HTI expedition
US special forces using the HTI expedition
US special forces using the HTI expedition
US special forces using the HTI expedition
US special forces using the HTI expedition
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October 15, 2007 Access to clean drinking water remains a major problem in many parts of the world. Over one billion people lack this basic requirement on a daily basis, and water-borne illness has become the leading cause of death worldwide - on any given day, over 50% of hospital beds are occupied by people suffering from such diseases. In the face of these facts it is clear that any technological innovation that can help combat this problem is a worthy one, with water filtration systems such as the LifeStraw and the LIFESAVER bottle having recently grabbed our attention. Now new technology developed by Hydration Technologies (HTI) has become available that allows the user to easily create a safe, clean diluted sports drink from any contaminated groundwater source. Utilizing on a process known as "forward osmosis", the system requires no power, pumping, test strips or chemicals and is effective at removing life-threatening bacteria and viruses, even from sewage-like waters.

US based HTI have developed what it believes is the world’s first commercially viable forward osmosis membrane. This membrane has been used by NASA, the US Department of Defense, branches of the US military and is now available to the public. The HTI products employ a proprietary membrane filter that is hydrophilic (attracts water), allows water to pass through, yet blocks very small contaminants due to the tight construction of the membrane. This allows a pure drink to be created from almost any water source, including highly turbid and toxic supply waters.

A key innovation is that this is a passive system - requiring no pumping - which harnesses the osmotic potential created by the sugars and electrolytes in a sports drink syrup as the energy source to drive the filtration process. This means that the resultant drink is not simply water, but is instead a dilute sports drink, providing electrolyte replacement and a calorie source for users. A standard sport drink syrup is placed on the clean side of the membrane, which provides osmotic pressure to draw the water across the membrane thus negating the need for any manual pumping, external power, mechanical parts or purifying chemicals. Also, because the system uses osmotic pressure instead of hydraulic pressure, the system doesn’t have the clogging or fouling problems inherent to other filtration systems. HTI claim that even highly turbid water, such as those found in the foulest ditch, will not clog HTI products.

HTI system advantages:

  • doing away with the heavy equipment and large quantities of on-site energy needed for heat sterilization and distillation;
  • eliminating complex in the field guesswork of dosage decisions associated with chemical treatments;
  • effectiveness in filtering out a wider range of contaminants than activated carbon filtering solutions which are unable to cope with many bacteria, viruses and chemicals;
  • not requiring training or relying on mechanical parts, an energy source, and replacement parts like pump systems do;
  • abolishing the need for external power to create the necessary hydraulic pressure and not suffering the fouling and cleaning problems common that occur with reverse osmosis membranes;
  • The system can even convert sea water, although a special “SeaPack” containing substantially more sugars is needed to cope with the inherently very high osmotic pressure of water containing salt. Also, due to the extremely tight membrane, HTI filters are capable of rejecting close to 90% of the salts in urine so, in a crisis, HTI products have been used to filter urine and have been credited with saving lives.

    This claim has been put to the test in Iraq by a six man group of stranded US soldiers led by Capt. Eaton. When re-supply flights failed to show at an Iraqi airfield the unit was faced with a dwindling water supply so, to supplement their rations, the group urinated into a common container and used the HTI system. The system extracted water from the urine while rejecting salts and poisons and helped sustain the unit for two weeks before supplies arrived. “I’d estimate that we got a 50% to 60% return on volume, which was a key to our survival. And it tasted great!” said Capt. Eaton. Now that’s a testimonial.

    The filters were developed in concert with the US Department of Defense and have undergone extensive testing in independent laboratories and by the U.S. military. The nominal pore size of the HTI forward osmosis membrane is 3-5 angstroms so bacteria, with a size ranging from 2,000 to over 500,000 angstroms, pose no problems. Even the smallest viruses, which measure 50 to 1,000 angstroms, are filtered out. To put this in perspective, if HTI’s membrane pore is compared to the size of a dime then the smallest bacteria would be larger than a two-car garage.

    In another example of their effectiveness, when tested by the U.S. Air Force, HTI filters converted anthrax laden source water into pure drink. Even with more than 1.2 million bacteria per ml in the water overnight, no bacteria were detected in the filtered drink, nor was the Anthrax antigen detected.

    Bacillus anthraces Sterne (Anthrax) is the bacteria strain referred to as anthrax. In addition, the anthrax antigen was not detected in the drink.

    The HTI range including the X Pack, Hydrowell 24 and Hydrowell Expedition, have a limited lifespan to filter a specified liter of water within a designated time at an ideal temperature range of 20°C to 30°C. For example the X Pack lasts ten days from first use while filtering a liter of water in four hours at 20°C or a liter of water in 3.2 hours at 30°C. The HyrdroWell lasts 30 to 90 days but must be flushed once a week and filters a liter of water in an hour at 20°C or 1.3 liters of water in an hour at 30°C.

    HTI says that their range of forward osmosis products are so easy to use that even a child can take muddy, life threatening supply water and turn it into a life-sustaining drink at a rate of up to 2 liters per hour. HTI’s water filters are used by the U.S. military, including elite fighting forces, and disaster relief organizations. They have proven themselves under some of the most demanding and extreme conditions, such as the Hurricane Katrina response effort in New Orleans. The products are also under review by the Australian Defense Force and about a dozen more Asia Pacific countries including Japan, Hong Kong and Malaysia.

    For further info visit HTI or, for readers in the Asia Pacific region, see Pacific Defence.

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