Covered Topics

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Thursday, June 27, 2013

Water Everywhere, But Nary a Drop To Drink

In a recent post I mentioned how potable water is becoming a scarce commodity. Indeed, only about 3% of all the world's water is drinkable - the rest is seawater. Of that drinkable 3%, a substantial amount is in a huge lake in Siberia. In much of the developing world, there is still a huge burden of disease and mortality due to drinking contaminated water. Diseases such as typhoid and cholera still plague the Third World. The World Health Organization estimates there are 3- 5 million cholera cases world wide and that of these, 100,000+ will die. This is cholera alone; typhoid, river blindness, and other diseases compound these numbers.

Here in the United States, we do enjoy drinking water standards that are the envy of much of the world. That said, that does NOT mean that all is well here. It isn't. Any google search of "tap water contamination", or anything along those lines, will turn up a plethora of articles about the heavy metal contaminants, the harmful microorganisms, and even prescription drugs in measurable quantities in municiple water supplies. Fluoride, which is routinely added to municipal water supplies here in America, was used in the drinking water in Nazi prison camps to make the prisoners easier to manage. The Nazi doctors knew well that fluoride lowers IQ and brain functioning, reduces a person's volition, and is basically a poison. Yet we deliberately put this in OUR drinking water???

Even without these issues, water quality is still impacted whenever there is a hurricane, or a water main breaks in a city, etc. Annually, there are tens of thousands of water main breaks in America due to infrastructure that was outdated 80 years ago. This not only causes water outages for millions of people, but it also provides opportunities for pathogens to enter their water supply during the break and repair process. During the Katrina disaster in New Orleans, there was oil and gasoline from cars, sewage, and many other pollutants introduced into the municipal water supply due to the flooding. This is normal during such flooding events, and such conditions may last for weeks - even after service is restored.

As part of my college studies, I have made simple, cheap, but effective water purification one of my areas of personal research. The most popular methods are:

1) Boiling or distillation - while these are effective, they use LOTS of fuel. In many Third-world countries, and in post-disaster scenarios, fuel for cooking or boiling water is a scarce resource.
2) Chemicals - Chlorine Bleach or Halizone are well known by outdoorsmen and others, but these impart a bad taste to water, don't last long in storage, and are not always available. Chlorine can also combine with other chemicals in water to produce carcinogenic (cancer-causing) compounds. Also, something - such as activated charcoal - still has to be done to remove chemical pollutants.
3) Micro-pore filtration - works well. Basically this uses a ceramic fliter element that can filter stuff to less than a micron, which keeps out most microorganisms. These filters are expensive, can clog, and also generally aren't available during emergencies and in Third World countries. Also, something - such as activated charcoal - still has to be done to remove chemical pollutants.
4) Carbon filters - or "activated charcoal" - does a great job removing chemical pollutants from water, but another method is needed to remove the microorganisms that cause Giardiasis, cholera, typhoid, etc.

I am personally researching several alternative methods of water purification - some are easily replicated at home by someone with reasonable mechanical skills. These include:

1) Solar water purification - while NOT a filtration system, sunlight can and does kill pathogens if the water is exposed onge enough. Some method of pre-filtering would still be needed to remove particulate matter that could harbor pathogens. The pre-filter could be as simple as several layers of coffee filters. The solar method can be as simple as leaving a plastic water bottle lying in the sun all day. A curved aluminum foil reflector would be placed behind the bottle and used to concentrate the rays so both sides of the bottle are irradiated.
2) Ultraviolet light - UV light in the 260 nm wavelengths is widely used in industry and food processing to kill pathogens. Likewise, it is used successfully to decontaminate water. Similar in concept to the solar purifier, it is generally done with special fluorescent lamps and is more easily controlled and repeatable than the solar method. Also needs a pre-filter as does the solar method.
3) Ozone - an elegant solution, ozone kills pathogens AND neutralizes numerous chemical pollutants. Ozone is a special, highly reactive form of oxygen molecule that has three oxygen atoms, rather than the normal 2 that we breathe in the air. Ozone may be generated via UV emitting fluorescent lamps or by electrical corona discharge through air. A car ignition coil with a simple transistorized oscillator circuit can generate the 20KV or more needed to make a decent corona discharge in an enclosed tube fed with air from an aquarium pump.

It should be pointed out that sources such as rain water or water pulled from lakes and streams should ALWAYS be pre-filtered due to the presence of fine particulates that microbes attach themselves to. Indeed, my own lab tests show that using a simple paper coffee filter to remove these particles causes a substantial reduction in bacteria even before any other methods are employed to decontaminate the water. In exigent situations, a tee-shirt or a bandanna folded multiple times can work too. In a future post I will detail an easy and cheap way to test your water at home for bacterial load, and will go into more specifics on homemade water filters using common household materials.

Meanwhile, here are some links to articles dealing with bad stuff in our tap water:

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