Two parts hydrogen and one part oxygen—these three tiny particles make up one of the most vital pieces of our human existence. And while hydrogen and oxygen form water at its most molecular state, hundreds of invaders find their way into our water sources every day. “Cleaning up” water and making it safe to ingest is an extremely important task in making sure that we have potable water we need to survive.
Without clean drinking water, we risk disease and even death. Thankfully, humans have learned and developed processes to create safe water from even the poorest of sources. Filtration and purification are two processes that help sustain healthy water sources. Clean drinking water is a vitally important issue and understanding the processes needed to make it safe helps ensure you continue to drink and cook with safe, clean water.
Filtration Versus Purification
You may see bottled waters sold in stores labeled as “pure” or “purified.” You may even have a water filter on your kitchen faucet or in your refrigerator. So what are the differences between filtration and purification?
On the simplest of levels, filtration is the process that removes solid particles from a liquid or gas. Water filtration removes fine solid particles such as sand, grit and dirt from the liquid making it smooth and particle-free.
Used in conjunction with filtering, purification is also a process used to clean a water source. While filtration removes small physical particles from the water, purification works on a more molecular level.
Purification removes harmful bacteria, chemicals or other biological contaminants from a water source. Filtration is often used as a part of the purification process although purification is the most important step for creating safe, clean, potable water.
How Does Filtration Work?
As explained previously, water filtration is the process of removing particulates from water, including grit, sand, dirt and other solid particles. The most powerful filtration systems can remove particles as small as bacteria. Filtration makes water appear cleaner, although does not necessarily make water safer since it doesn’t remove things like viruses or other contaminants.
Filtration uses a physical barrier, chemical process or biological process to remove the impurities from a water source. The process allows the good stuff, in this case the water, to pass through the filter while the bad stuff—dirt, sand, sediment, pollutants—gets filtered from the water.
One popular method of filtering water is carbon filtering. Carbon filtering uses activated carbon to filter sediment and impurities. Activated carbon filters water through a process called adsorption. Adsorption causes small molecules and various pollutants in the water to become trapped inside the pores of the carbon. Carbon is most effective when used to remove sediment, chlorine and volatile organic compounds (VOCs) from water. Carbon filters also remove poor odors and taste from water although it cannot adequately remove particles such as minerals and salts.
Carbon filters are often used as household water filters and the technology has even been translated to work for camping, survival and emergency kits. In small form, carbon filters can be purchased and packed into outdoor gear as well as emergency survival kits. When used in conjunction with water purification, filtration systems create potable water in nearly any situation.
How Does Purification Work?
Like filtration, water purification is a process used to remove undesirable particles and contaminants from water. Purification typically takes filtration a step further, and often uses filtration methods as part of the purification process in an attempt to ensure the water is safe for consumption. Water purification removes various biological contaminants, including chemicals, gases, and solids, that cause severe harm when ingested by humans. Purification does not necessarily make water appear cleaner or clearer and it does create safe, potable drinking water.
Water purification is a multi-step process that typically envelopes several smaller processes, including filtration. Depending on the type of impurities found in the water, various techniques may be employed to help purify a water source.
- Disinfection is often needed to treat polluted water.
- Chlorine is often used to disinfect water.
- Chlorine, or in some cases iodine, shocks the water source and can clear the water of dangerous micro-organisms. There is a fine balance needed when using chlorine or iodine to disinfect and purify water. Both chemicals have to be used in exact measurements and can be tricky, as too much of either can be harmful if ingested.
- UV light treatment is another option for disinfecting water and is generally considered a safer option as there are no harmful chemicals used in the process and disinfection occurs immediately.
Reverse osmosis is one of the most recognizable options in water purification. Osmosis happens when water is diffused across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. Reverse osmosis is the opposite of this process. Reverse osmosis occurs when water is forced across a membrane from a highly-concentrated area to a low-concentrated area. As the high pressure forces the water through the membrane, the membrane works to catch and trap the undesirable contaminants in the water. The reverse osmosis portion of water purification is considered to be one of the most effective pieces of the water purification process, as it traps and removes most micro-particles in the water source.
Reverse osmosis is highly efficient at removing particles from water sources. It is a popular choice to remove salt, iron and other minerals from water. It is often used in conjunction with filtering processes such as carbon filtration to completely and properly create potable drinking water. While filtering manages to remove much of the sediment and larger particles found in water sources, purification can remove dangerous organisms such as bacteria and viruses and is what ultimately creates safe, potable drinking water.
Why is clean water so important?
Lack of access to clean water is one of the world’s largest problems and environmental water contamination is one of the world’s biggest killers. According to the World Health Organization (WHO), diarrheal diseases affect nearly 1.7 billion people a year, killing approximately 760,000 children under the age of five each year. The lack of safe water drinking sources around the world significantly contributes to diarrheal diseases. While the United States and other developed nations have managed to create potable drinking water on a large scale, many countries and their citizens are still without access to clean water.
On a smaller scale, access to potable water is a concern in emergency or survival situations. In the wake of a natural disaster or in a wilderness survival situation, water sources may be compromised or even non-existent. Tools to filter and purify water are often found in portable packs and units designed to fit in backpacks and survival kits. Having a basic knowledge about water purification and filtration principles is key to understanding, and ultimately creating, a safe source of water even when using a prepackaged unit.
Have you ever been without good drinking and cooking water? How did you handle it? Would you do anything differently for the future. Share in the comments section.
Thanks Stanlie. Your navy experience just verified what my eighth grade science teacher taught us years ago and I hope I’m on the right track as far as prepping is concerned. I’ve tried iodine, halazone tablets and chlorine as means of water purification and neither of them encourage drinking the result.
For earthquake preparedness I have set aside six 5 gallon plastic bottles of local tap water with 1/2 teaspoon of chlorine bleach added as per ARC recommendations. I change them out every six months but they still smell and taste like they came directly from my neighbor’s swimming pool.
Each toilet tank in the house, (2), holds a gallon and the water heater is good for another thirty gallons so I’ll shut off the house supply to protect it from contamination. I try to keep a couple of cases of bottled water on hand just in case, but my wife and I hope it could last at least a couple of weeks. I saw what happened in a number of southern states after Katrina and I don’t want to fall victim to that. Comments please folks. Hank
Almost all store bought individual water kits both filter and purify your water in the wilds The more expensive yet still individual carry units can remove up to 90+% of radiation.
Every camping kit should have at least the cheapest straw er r for individual.
They clean several gallons before going Tits-up.
The better kits have replaceable and reverse flush clean out possability and do thousand gallons.
No prepaid is a serious preppie unless they have own bladder bags and a personal filtration system to fill with.
Some kits take awhile.
You can build relatively large charcoal and sand reverse osmosis but that is for staying put and damned slatHered are solAr heAted still that come packaged and only take up a 1″x 4″x 51/2″ space and weigh under two pounds. Way under.
Yup buy you still need Lorraine or iodine tablets iodine best and get the iodine phosphate types.
You can filter through clean unused gas mask filters in an extreme emergency. They will catch most harmful solids depending on mask capability.
In extreme shortage your urine can be recycled for short while but instead of using precious clean wawater er to cleanse a wound use urine instead.
Err fever can kill you damned quickly and it is very prevalent in all western streams.
I worked on a distillation plant for 4 years when I was in the navy. If you took sugar water and purified it, or filtered it, you would still have sugar water. If you distill any water, you will have absolutely pure water with nothing in it. You cannot find distilled water in nature. If I was seriously thinking about long term survival from a possible nuclear war or a extended period of unrest. The first thing I would do is buy an old distillation plant off of a yacht and restore it and move it to my survival lair. Well, all the rich have already done just that. Stan
Did I miss something? What about boiling your water, or even better distilling it? I seem to recall that in the field sanitation they taught us if you boil water at a heavy rolling boil for ten minutes it would kill anything in it. Sadly, you lost a percentage of it but it was deemed to be safe. I know that was a long time ago and memory fades.
I also remember a guy who built a still to distill and purify water. He started out with a big pot and had a cooling condenser coil of tubing coming out of the top. What dripped out of the other end was cooler crystal clear water. He was going to try to market it to sailors as a back up supply on long trips. That too was a long time ago. Anyone have any recent intel on these methods? Hank
That link to modern survival blog doesn’t address the central issue, but it was mentioned in one of the comments toward the end of the comment section. You see, you put a lot more stuff in a pool besides chlorine. There are chemicals to raise the pH and chemicals to lower the pH. The pH has to be right, or the chlorine is not as effective. Also, the chlorine compounds that you use in a pool contain a stabilizer chemical, which is poison — but it is a small amount. Then there are the various algaecide products, for several types of algae. These algaecides are also the source of small amounts of poison. Now, it’s true that the occasional gulp of swimming pool water will not make you sick. But what about using that water long-term? For all of your food preparation and drinking? Boiling will probably not get the chemicals out. Unless you distill the water, there are going to be some chemical compounds in the water. So, my question is, how safe is it to use this water over the course of an emergency lasting several weeks or months? I haven’t found a web site that addresses this yet.
Just a quick google:
How do you make a swimming pool a source of drinking water? I have 10,000 gallons of water with no bacteria, but I have to put a ton of chemicals in it maintain the pH and kill the germs. Is it safe to drink as-is? Or do I need to filter it? Or boil it? If anyone has hints please let us pool owners know…
I’m going to the route of saying that for most people, in general good health, filtration is probably all you really need. The odds of getting a disease from decently filtered water is low.
The other thing before applying that is what situation are you in? If you and others are trapped in the foothills of some mountain and will probably be able to civilization with a few days walk, go for it.
If it is the zombie apocalypse then you may want to be more careful.
For example, downtown NOLA post Katrina, you can filter a few gallons of water and then walk out. There are medical treatments available later if you do pick up something. Post nuclear war, you may not have a hospital left.