Combine sunlight and sewage and what do you get? Sanitation, of course.
Michael Hoffmann at the California Institute of Technology has been experimenting with solar-powered water treatment on a small scale. Now he plans to incorporate this technology into a portable toilet.
Sunlight powers an electrochemical reaction with human waste in water that generates microbe-killing oxidants and releases hydrogen gas. The researchers plan to collect the hydrogen in a fuel cell to power a light or possibly even a self-cleaning mechanism.
He received a grant this week from the Bill and Melinda Gates Foundation to build a prototype. He says he can build one toilet for $2000 and hopes to reduce the cost through design refinement and mass production.
This grant is part of the Gates Foundation’s latest global public health initiative to improve sanitation.
Several other awarded projects propose to build toilets that generate energy for the community, either processing solid waste into biological charcoal or vaporising it into plasma that generates hydrogen and carbon monoxide to run a fuel cell.
According to World Health Organization estimates, 2.6 billion people – about 40 per cent of the world’s population – do not have access to sanitation.