Just a handful of ingredients

November 22, 2012

Imagine a combination of terra-cotta, yesterday’s coffee grounds and cow dung. How could this combination possibly be useful? Maybe an innovative oven? An extraordinary kind of fuel? Or maybe you can use it as building material? It is, in fact, the basis of a special kind of personalised water filter which removes common pathogens including E.coli.

Tony Flynn, a materials scientist and ceramics lecturer fromThe Australian National University invented this grassroots alternative to higher-tech filtration systems using locally available materials. And the best thing is: The filters can be made by anyone and they are free! All that you need is access to the three different ingredients: terra-cotta, ground coffee or another organic material and sufficient water to create a thick mixture that can be formed into a pot. After drying time in the sun, the pots are fired on a bed of dry cow dung and left for 45 minutes. But how come the cow dung is dry? It’s a very efficient and hot-burning fuel, reaching a temperature of 950°C in less than 30 minutes. And it burns hotter and faster than traditional ceramic kilns.

 

The firing process burns the organic material and small pores are left. Through these tiny holes water will pass but pathogens and fine colloidal material that can make water muddy and unpleasant will not. The filters safely remove over 95 percent of all E.coli bacteria and can filter 1L of water in 2 hours. To clean particularly contaminated water several filters may be used in sequence.

Caroline Weimann
Caroline Weimann

Caroline Weimann is member of the “empowering people. Award” team at the Siemens Stiftung (foundation). She studied International Law, Economics and Diplomacy at the School of Oriental and African Studies in London as well as Languages and Literature at the University of Oxford. Before joining the Siemens Stiftung, she worked on health and development issues at the European Commission and at a consultancy firm for non-profit organizations.

 

Function:
Basic Needs & Social Entrepreneurship

Topics

  • Water & Waste Water
  • Food & Agriculture
  • Success Stories
  • Water & Waste Water
  • Food & Agriculture