Can You Use Sapwood for a Filter?

You have seen the photo by now haven’t you?  A picture of a small piece of wood, tubing, and a clamp.  Then the declaration is that it will serve as a water filter.  Many, many folks have sent it to us and asked our opinion.  Here are some initial thoughts from several different perspectives.

• As a naturalist I see this sort of thing and think, really?  This surprises you???  Suffice it to say nature is pretty cool.  I have personally witnessed so many wonderful things that continue to bewilder me such that I keep going back wild places as often as I can?  I teach using vegetation as a filter when you have no other source to help you filter water.  Anything that grows has built in filters to it.  You, me, a tree branch, and virtually everything green.  Without hard data before me to tell you if this particular setup works, I simply cannot do so.  Do I, however, think it is possible for this to work?  Why yes, I have absolutely no doubt that this could work.
• As a statistical geek (Bachelor’s Degree in Statistical Analysis) there are some things that jump out at me in the article.    First off there are a few times that the researchers are cited and they use terms like most and possible.  This typically denotes that a scientist is trying to arrive at an intended result.  In my statistics training we were taught as statistical writers to utilize numbers when they proved the point we wanted proven, and to use words when the data did not help our cause.  I see that in this article. 
• From a survival perspective I must note that while this method was good at eliminating e coli and other bacterial contaminants, the authors noted that it does not remove viral (much smaller) or chemical contaminants.  If the truth were to be told, viral contaminants are not widespread in our part of the world therefore I am not overly concerned about that.  Chemical contaminants however, that is a different story.  Due to groundwater contamination, all over the world this could be prove to be a problem.  If you want to understand the science behind why this works (or if you are looking to find something to put you to sleep) then check out the this article on Van der Waals force.  It details why some molecules bond to others, while others do not.  I utilize this when I teach survival to help people to understand why a carbon filter works.
• Again from a survival perspective.  If I am going to be putting in something such as piece of tubing, clamp and epoxy into my pack or go bag to make this apparatus work, I am instead going to put in a container in which I can boil water.  I would also include a water filter which does the same.  
• DIYer.  This is so cool these days.  Make something out of nothing.  For this reason this experiment and how to go about doing it is pretty cool in my book.  

So looking back at these points…I guess it all points back to this is pretty daggone cool.  For me and my money I might make a Hillbilly Water Filter instead.  This guy on youtube doing it is so daggone good looking!