Thursday, August 20, 2015

The Drinkable Book

One of the members of our Facebook Page found an article covering a new method of cleaning water and wanted our thoughts on it. Since I am the resident water “expert” (I'm trying not to laugh), I looked into this new invention and have some information and opinions on it.

The Drinkable What?
The concept was a student's PhD project to develop a cheap, simple method of treating water to make it less dangerous to drink. The inventor (Dr.Theresa Dankovich ) uses specially manufactured paper to create a water filter that will kill bacteria and screen out the larger particles. Since it's made of paper, she bound it in the form of a book to make it easier to transport and store. Each page is perforated and a half sheet is used at a time. Depending on the raw (untreated) water quality, she claims up to 30 days usable life for each filter, so a 25 page book (50 filters) could last a person about 4 years.

The Paper
The paper is treated with silver and copper nanoparticles which have antibacterial properties. The exact quantity, size, and distribution of the silver and copper particles isn't mentioned, but to be proper nanoparticles, they would have to be between 1-100 nanometers in size. For a quick math refresher there are 1000 millimeters (mm) in a meter, 1000 micrometers (um or microns) in a millimeter, and 1000 nanometers (nm) in a micron. For those of us that don't speak metric, there are 25,400,000 nm in an inch.

Currently the paper is being hand-made by the inventor in a church kitchen. The chemical treatment and drying of the paper is time consuming, and she's working on getting the whole process scaled up for industrial production at a small paper mill. She has the backing of a mid-sized charity and a PR firm, so I think she has a good shot at making it into production.

The project has a Facebook Page with links to their most recent activities.

The Filtering
The book comes packaged in a plastic box. Half of the box is used to hold the piece of filter paper (half of a page) and the untreated water, and is placed on top of the other half of the box which catches the treated water. As a reader pointed out in the Facebook comments, this is a flaw which presents many opportunities for cross contamination when the system is not in use. Placing the book back into the box after the book has gotten dirty or while the box is still damp/wet is a design flaw that should be fixed. The only thing that could allow this to be acceptable is the fact that the filter is killing bacteria instead of just physically removing them from the water.

It is important to that that this is a water disinfection device, and it works only on microbes in the water. It will do nothing for chemical pollutants or metals like lead and arsenic, nor will it desalinate sea water to make it potable.

The Results
The inventor is a chemist, so she knows how to run lab tests properly. I trust her when she claims better than 99.9% reduction in bacteria by using her filter. She claims it meets EPA standards for drinking water, but that would be for bacteria only.

Reducing bacterial contamination by 99.9% is not all that good compared to some of the water purification systems we have available today, but for a cheap and easy system to be given away in undeveloped area of the world it would help. Knocking the bacterial load in your water down makes it easier for your body to handle the remaining bugs.

I'm still digging through reports, trying to find out what exactly they tested it with. Raw water from some third-world mud puddle was the harshest test I've seen it pass so far. I'm trying to find the numbers for efficacy (power to produce results) of her filter on Giardia and some of the other common microbes. E.coli is the standard bacteria for water testing because it is found everywhere, but it is not always a good indicator of how well a system will work against other organisms.

My Take on the Whole Thing
I like the idea of a simple water filter that is capable of destroying 99% of the bacteria present. For use in undeveloped areas, areas affected by major disasters, or when traveling through areas with microbes that your body is not used to (Montezuma's Revenge) it makes sense.

Right now the emphasis seems to be helping out people who don't have access to clean water on a regular basis. I think that they could fund a lot of charity work by developing and selling a system for the emergency equipment market. We'll have to wait and see if it ever gets sold commercially.

The use of gravity instead of pumps means that it is simple and the lack of moving parts means it is unlikely to break. The plastic box is a weakness, but pictures in the video do show the paper being used in a funnel like standard lab filter paper.

Using nanoparticles to do the disinfecting is an untested field, so I'm going to have to wait for more information before passing judgement on its effectiveness and longevity.

Silver and copper do have antibacterial properties, and as elemental metals they have no defined shelf-life. They are also neither consumed nor depleted in their use, so the amount of water that one filter could treat would be determined by when the paper carrier gets clogged or falls apart.

This type of filter would be unaffected by freezing or heat (as long as it didn't ignite) and could be stored indefinately. A perfect application for a filter of this type would be in emergency kits stored in airplanes or fresh-water boats. Having something the size of a sheet of paper that can disinfect your water for a month would be handy when traveling in wilderness areas by canoe, kayak, or foot.

I'm not going to throw away any of the water treatment gear that I already own and replace it with a Drinkable Book if/when it hits the market, but it might be handy to have as a plan C or D. If they get rid of the plastic box and shape it into something that will fit a normal container, it would be a welcome “extra step” in being prepared to clean my own water. Pricing is always going to matter, but they'd be insane to try to put a big price on something they want to be able to give away to people in need.