Filtration vs. Purification
Filtration vs. Purification
Today, let’s take a few minutes to discuss the difference between filtration and purification. Believe it or not, there is quite a bit of confusion; disagreement; contention; deception; misunderstanding and downright ignorance as to the meaning of these two words.
Before we dive into things, did you know that women in India, Bangladesh, Pakistan, Sri Lanka and Nepal have traditionally worn a garment called a Sari, or Saree, (which means wrap or strip of cloth in Sanskrit) for millennia? Now, you might be asking yourself what in the world does this have to do with filtration and purification?
Consider this: women in these parts of the world have been using their Sari’s as a water filter for thousands of years! In fact, lab tests supported by the Thrasher Research Fund showed that 4 layers of cotton material (the main material of traditional Saris) held back more than 99% of cholera bacteria. There were even onsite studies of nearly 45,000 residents in the region which supported the fact that cholera incidence was dramatically reduced by using Saris as filters!
Fortunately, for virtually all of us, we don’t have to worry too much about cholera or other bacterial diseases caused by contaminated water. However, the proliferation of tens of thousands of other contaminants found in water supplies around the world should give us great cause for concern. Thus, we should examine the difference between filtration and purification.
In general, the word filtration simply means the removal of solid particles from a liquid or gaseous fluid. Of course, there are other definitions but this one is very general in nature. As a simple example, a brand new white athletic sock tied around a water tap is a somewhat crude filter. If you try it, you might be surprised at how much “stuff” you would find at the end of 2 or 3 weeks of use!
Now, the size of these “solid” particles can vary greatly, especially in ordinary tap water. Have you ever removed the aerator from the end of your water faucet? You’ll almost always find chunks of stuff in there. Remember, though, that in the water treatment industry we often use the term “micron” to describe particle size. To give some perspective, one micron is only one millionth of a meter! For example, one grain of ultra fine powdery beach sand is about 60 microns in size (0.0025 inch). Medium sand is about 250 microns in size. Bacteria can range in size from .3 microns to over 10 microns in size. Finally, the smallest particle you can see with your unaided eye is about 20 microns in size.
Most very GOOD filters (and the majority of filters being sold today aren’t good!) are able to remove particles as small as 5-10 microns in size. However, please keep in mind that many of today’s water borne contaminants are in the SUB-MICRON range! For example, an average virus is around 0.02 microns in size. A virus will pass through a 5 micron filter easier than a mosquito will fly through a chain link fence! Let’s not even talk about dissolved substances in water, which are even MUCH smaller than a virus. These include “forever chemicals” (PFAS; PFOA; PFOS; etc); traces of pharmaceutical drugs; PCP’s (personal care products like shampoos; detergents; etc.), pesticides; herbicides; dissolved metals like lead; mercury; and so on.
Does anyone think an average water filter can remove such microscopic contaminants? The answer is NO! You need a purification system to reduce contaminants this incredibly miniscule.
As a final point for today’s discussion, it’s important that you understand that our AquaTru water purifier’s RO membrane has an effective porosity of 0.0001 microns! Try to imagine something as small as 1 millionth of a meter, then further divide it 10,000 times. It is hard to put into words, but anything larger than 1 ten thousandths of 1 millionth of a meter is effectively “blocked” by the membrane!
In today’s world, we need a purifier and not just a filter. Of course, a filter is better than nothing. But many filters being sold today are actually worse than nothing! How is that possible? In addition to this topic, in our next discussion we will consider the importance, and the differences, in the carbon being used in many of the filters and purifiers currently being sold.
In future articles, we will also talk about the deception being foisted upon the public with so-called “Alkaline” water filters. We will also go into an in-depth look at the statement “R.O. purification systems remove even the “good stuff” from water.” Here’s a hint: Not True.
We will also look at the importance of adding the entire periodic table of elements to our pure water. There is so much to talk about.
Take care, stay hydrated, stay healthy!