Tags
activated carbon, biosand filter, clean water science, engineering, gravel, life straw, LifeStraw, sand, water filter, water purification
Another entire day without seeing the sun. Ah, the life of an engineer with an ever-approaching deadline. I love my job though, so it works out. Not to mention, I get to come home to this:
The surprise gift my husband got me yesterday while he was out shopping for winter clothes. He totally gets me. Granted, he still surprises me with flowers, love notes, and date nights, which I am so grateful for, but this was a whole different kind of great. I love science, but most importantly I love all things water. I used to try and be secretive about it, in fear that my closet nerdiness would scare people, but now I embrace it, and it makes life a whole lot more fun!
For those of you that do not know the basics of water purification, let me lay it out for you. There are many different kinds of water filtration, and this particular one is called a Biological Sand Filter. There are 4 main filtering mediums working together to purify the water. These mediums can be found locally and do not require electricity to operate. The water runs through each medium and particles of specific sizes are trapped until the only thing that remains is clean water. These mediums are:
1) Gravel – traps small bugs, dirt, etc
2) Sand – traps algae, zooplankton, etc
3) Activated Carbon – uses adsorption to make the organic matter in the water stick to the activated carbon while also reducing odor and taste
4) Filter Paper/Mesh
* I could go in to a more detailed analysis of this process in a later blog if you are interested.
With this experiment, we mixed dirt from the garden and vegetable oil into some tap water and poured it through the combined filter devices listed above. The results? Oily water. Hey, what can you expect from a toy. But seriously, the principle behind this experiment is exactly how people have been purifying water all over the world since the early 1800’s. This toy cost $13 at a store, but these devices can be made for about $1-2 in a more accurate and useful fashion. Check out the Life Straw for example (http://www.vestergaard-frandsen.com/lifestraw), an amazing device that removes the parasites that cause diarrhea – a deadly disease in many parts of the world, killing over 1.5 million children each year from dehydration. This device also removes many other common water pathogens and is very user friendly – basically one just drinks through the device like a large straw and as the water is sucked through the LifeStraw it is purified. To prevent clogging of the filter media, the LifeStraw user simply blows into the device periodically – brilliant! This is just one of many devices I find fascinating, economical, and absolutely necessary.
The kit went on to describe methods of setting up a Distillation experiment (water evaporation, used mainly in desalination plants), and a Solar Pasturization experiment (heating up the water to a specified temperature that will kill the water pathogens). All of these things are great, but they require money and labor to reach the 1/5 of the world’s population that does not have access to clean drinking water. Next time you turn on your faucet, take a shower, or flush your toilet, say a prayer of gratitude and ask if/how God wants you to help in this world crisis.