Most everyone who is familiar with survival is also familiar with the need to say properly hydrated. However, finding fresh, drinkable, water in the outdoors can sometimes be a bit difficult due to such bacterial contaminates as Giardia. Thus, there are now numerous manufactures who produce portable water filters that remove these various microbial contaminates. However, most of them are designed to work only with clear water but not with turbid water because the silt that causes the turbidity clogs the microscopic pores of the filter. In addition, chemical and ultraviolet water purifiers are often not able to penetrate turbid water in order kill the microbial contaminates. However, after doing a considerable amount of research into this problem, I recently discovered a filter that will not only remove microbial contaminates from turbid water, it will also remove salt from salt water without clogging the filter because it works using the principle of forward osmosis which causes individual water molecules to migrate through a membrane.
This filter is made by a company called Hydration Technology Innovations (http://www.htiwater.com/divisions/personal_hydration/) and it was originally developed at the request of the U.S. Military to allow its troops to extract drinkable fresh water from any available source! However, unlike other water filters, this filter uses the process of forward osmosis to remove silt, salt, and microbial contaminates. In fact, according to the HTI web site, “HTI’s revolutionary forward osmosis water filtration products were originally developed in cooperation with the US Department of Defense for soldier hydration. Funded by the Defense Advanced Research Projects Agency (DARPA), the goal of the project was to develop a means by which a soldier could drink any water found on the ground, no matter how contaminated. There were a number of water technologies involved in the project but, critical to meeting the goals of the military was the ability to work well with muddy or turbid water. DARPA understood that forward osmosis was the only technology that had the potential to work unimpeded in thick, dirty water”. Thus, since I am an avid outdoorsman who has often had a need for just such a product, I wanted to make our readers aware of this company and the various water filters they produce.
For those of you who are not familiar with the process of osmosis, it is defined as the process by which solvent molecules (in this case water molecules) spontaneously move through a permeable membrane to an area of higher solute concentration in the direction that tends to equalize the concentration of the solute. Thus, in the case of this filter, instead of using gravity or kinetic pressure supplied by the user by squeezing the container to move water through the filter, a “syrup” is added to the reservoir to create a hypertonic solution that causes the water molecules to migrate through the filter without the input of energy from the user.
However, unlike other water filters in which drinkable water is available almost immediately because the water passes through the filter fairly quickly, osmotic filter systems do require a certain amount of forethought and planning because the process of osmosis requires longer to work. Thus, in most cases, when using an HTI water filter, a waiting period twenty-four hours is required in order to produce fresh, drinkable, water. In addition, each time you use the filter, you have to add a “syrup” to the reservoir in order to create a hypertonic solution for the water molecules to migrate into. Also, unlike other water filters, the filter membrane must be replaced more often. Thus, my suggestion is to carry both a more conventional water filter for use with clear water and a HTI osmotic water filter for use with turbid or saltwater.
So, for those of you who frequent the outdoors in low lying areas such as swamps and marshes or arid areas such as deserts and semi-deserts where stagnant water is likely to be encountered or are avid sea kayakers who like to participate in extended expeditions where fresh water is likely to be hard to come by, the HIT osmotic water filter just may be the best water filter on the planet!
PS: Leave us a comment with your thoughts, what is the best water filter for survival?