Over 1.5 million people die every year from drinking contaminated water, specially children in developing countries. Imagine if you could get a portable tiny water filter that could be screwed into any plastic bottle which would allow you to safely drink any available water, from a stream, from a lake, from a water pond? Imagine what it would mean for a poor family in Africa to be able to get this filter for just $1?
Since I started playing around with carbon to make a cheap DIY conductive ink, I discovered the many cool properties carbon has. One of them is that it’s a very good material to filter liquids like contaminated water. Just 1 gr of activated carbon has a surface area of 500m2! It’s also a very cheap material to manufacture, mainly from coconut shells. After researching about filters for drinking water we have come up with an idea to design an open source tiny water dual ceramic/activated carbon filter that could be screwed into any plastic bottle and that would cost just $1 to manufacture. I believe this will be a great social entrepreneurship project for low income families to avoid other costly methods like using scarce firewood for boiling water and other harder purification methods.
As a first step to make a working prototype we published this Instructable to test a low cost DIY water filter that fits in a bottle, which actually works. From this simple experiment we envisioned a ceramic, candle shaped tube that would be attached to a water bottle cap, so that it can be screwed into any plastic bottle, you could suck and squeeze the bottle to drink filtered, clean water, thus helping recycle already used plastic bottles and above all offering an extremely low cost solution to the drinking water problem worldwide.
I hope it will take us about 6 months to have the first working filters ready. I already contacted manufactures in Asia which are willing to manufacture small orders for about $1.6 each, with specs like 0.2um pore size to filter 99.99% of bacteria.
Below is a video and basic points from the first DIY version of the filter, which served as an inspiration:
There are hundreds of DIY water filters out there on Instructables, Youtube, etc. There are many ways to make a survival or emergency water filter, the differences with our first filter using activated carbon and air pressure from your mouth compared to other methods are:
1. The real simple innovation in this design is that it increases the flow and rate of filtration by using air pressure from your mouth instead of waiting several minutes for the turbid water to be filtered by gravity as many other filters do. This simple innovation can help you filter lots of liters of turbid water per hour compared to just waiting for gravity to do it’s work through the filter. In an emergency situation or disaster, this could be a big difference!
2. It works It helps remove dust, particles, chemicals and even metals from turbid water. You can kill viruses and bacteria by adding a few drops of chlorine after the filtering process or placing the filtered water in a clear, clean plastic bottle under the sunlight for UV rays to kill them.
3. It’s small and portable, it fits in a 0.5 liter plastic bottle
4. It’s low cost, using available materials like a plastic bottle, filter paper or a piece of cloth or kitchen paper towel and cheap activated carbon (I bought 1 kg or 2.2 lb of activated carbon for $5, you will use 1/5th or around 200 gr)
5. It’s reusable. You can filter hundreds of gallons of turbid water. Once the rate of filtration becomes slower, you can just take out the activated carbon and replace it with unused carbon. You could use also charcoal, sand and gravel inside the bottle.