Kyle Poplin

A Chemist’s Novel Idea: Teri Dankovich invents a type of paper that filters water, then incorporates it into a ‘Drinkable Book’

Teri Dankovich is a chemist who invented a paper that purifies drinking water. As a way to get this special filtering paper to some of the planet’s 663 million people who lack clean drinking water, it’s been incorporated into The Drinkable Book, and actual book that includes information on why and how water should be filtered.

The system works like a high-tech coffee filter. Users tear a filter out of the book, place it in a custom box which is part of the book, and pour the water through. Field studies have shown that the paper kills bacteria in a variety of waters from throughout the world. Dankovich and her backers are currently fundraising and working on different ways to turn these filter papers  – which cost only pennies to produce – into a sustainable business. Below, she talks about how her research project has evolved and how she hopes it might one day save the lives of millions.

Kyle Poplin: I understand you’ve been working on this filter paper for years (since 2008). How’d you become interested in it, and how did the idea of a book come about?

Teri Dankovich: The project was originally part of my Ph.D. dissertation at McGill University in Canada. I started getting interested in using this technology to help people when I realized just how incredibly cheap and easy to transport it was. The main material cost of the filter paper is the paper itself.

The Drinkable Book project came about from a partnership with Brian Gartside (who was then a graphic designer at ad agency) DDB New York and the NGO WATERisLIFE. The book format was chosen as a way to provide health and water safety information to ensure correct usage of the filter papers. The book cover also acts to protect the paper filters.
KP: What diseases/bacteria can your filter paper prevent? Are you still working to perfect the filter paper or is that process complete? And how does the filtered water compare to typical tap water in the U.S.?

Teri Dankovich (left, in her lab): The filter paper’s active ingredient is silver nanoparticles, which are non-specific antibacterial agents. In the scientific literature, silver has been shown to kill all sorts of microbes including: E. coli, Listeria, pseudomonas, salmonella, staphylococcus, streptococcus, cholera. We found that in both cases of laboratory and field analyses of these filter papers that there were high levels of bacteria reduction, greater than 99.9 percent. The majority of the filtered water samples had zero live bacteria present, which is comparable to the the tap water in the U.S. However, our filters do not remove organic or heavy metal contaminants.
KP: What have you learned in your field trials? Are more planned?

TD: We have learned a lot about the feasibility and desirability of these filters. First of all, our field trials have successfully demonstrated the ability for the filters to eliminate bacterial contaminants in over 25 water sources in South Africa, Ghana, Haiti, Kenya and Bangladesh. During product demonstrations to rural communities in Southern Bangladesh, we had a very positive reception and very useful feedback in what prototype designs were most preferable. Typically, people wanted to purchase and to know when the filters will be available for purchase. They were very interested in how the filter works and ways to use it in their current household practices. Often villagers guessed that the filter is made out of carton paper or animal hide!

We do have more field trials planned. The next step is a pilot-scale implementation of these filters with several households in one village. After feedback from that phase, we plan to scale from one initial village where protocols would be established and tested, to several villages where protocols would be refined and finalized, and finally on the order of a dozen villages.


KP: What’s the content of the “book” part of The Drinkable Book?

TD: There are instructions on how to use The Drinkable Book printed on the filter pages in the book itself. The pages also include information on waterborne illnesses, and general advice if one was to become ill.


KP: How much does each 20-page book cost to make, and how much are the individual filters? How long will each book last and how much water can it filter?

TD: There are 25 pages and 50 filters in The Drinkable Book. Each filter can purify approximately 100 liters of water, which could provide an individual with water for a month or a family for about a week. The cost will ideally be 10 cents or less per filter, although we are not yet at mass production scale, so these costs are tentative.


KP: What’s the business model; how will the distribution of these books be financially possible?

TD: We plan to achieve long-term technological and economic sustainability through product sales to international NGOs and governments, as well as donor-sponsored implementation projects.
KP: Why not just distribute the filters, instead of making them part of a book?

TD: We are exploring multiple options for implementation. The book is our first version of these filters in a product, and will most likely be followed by other versions.
KP: What are the short- and long-term goals of your project? What will you determine its ultimate success?

TD: We aim to have completed the transition from prototype to thoroughly-tested product in the next one-three years. In the long term, our target goal is the bottom of the pyramid market: the hundreds of millions of people who earn less than $2 per day and do not have access to clean drinking water. Ultimate success will be determined if the filter papers improve the health of millions of people and if the filter papers become a household product in the bottom of the pyramid market.
KP: What major challenges are looming?

TD: Because we are still in the process of product development, our major challenges are currently in that scope, e.g. product design, user/product interactions, clear messaging, production scale-up, etc. We need to ensure that our final product design is robust and consistently functions correctly in the hands of end users. Clear indicators for when to replace the filter paper need to be established and communicated. Getting the paper treatment process from the bench scale to the pilot scale and mass production scale needs to happen.

Below is a video produced by WATERisLIFE:



Kyle Poplin is the editor of NextBillion Health Care.


Health Care, Technology
healthcare technology, public health