REINVENTING THE TOILET— AND SAVING LIVES

YU-LING CHENG, director, Centre for Global Engineering and professor, Department of Chemical Engineering & Applied Chemistry

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THE PROBLEM

Forty per cent of the world’s population—that’s 2.6 billion people—lives without access to basic sanitation. Western-style sanitation systems require expensive and extensive sewer and waste processing infrastructure and so are not adaptable to the developing world.

THE INNOVATION

A cheap, off-the-grid toilet that processes waste quickly and safely. It uses a sand filter and UV light to disinfect liquid waste and a smoldering process (similar to a charcoal barbeque) to incinerate solid waste that has been flattened and dried.

THE APPROACH

In 2011, the Bill and Melinda Gates Foundation awarded eight teams worldwide $400,000 each to develop promising processing and design concepts. The U of T team, led by Yu-Ling Cheng, and with collaborators from the University of Edinburgh and Western University, recently came in third in the foundation’s Reinvent the Toilet Challenge and was awarded an additional $2.2 million to continue its work.

THE IMPACT

The World Health Organization estimates that 1.5 million children die each year of diarrheal disease. This preventable disease is the leading cause of death in children under five. An inexpensive and effective toilet would make an enormous difference in the health of developing communities worldwide.

WHAT’S NEXT?

Cheng and her team are working with partners in Bangladesh and plan to have an operational prototype in place by December 2013. A design goal is to use materials and equipment that can be maintained locally.

“We have proven that our concept works technically. We are now busy trying to make sure it will work for the users—some of the 2.6 billion people in the world who do not have access to basic sanitation.”

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