University works on multifunctional, desirable toilet

A team of chemical engineers at the University of KwaZulu-Natal is hard at work trying to develop a high-tech, multi-use toilet that people in the developing world will want to own and use.

Last year the water, sanitation and hygiene programme of the Bill and Melinda Gates Foundation challenged 22 universities to submit proposals for the invention of a waterless, hygienic toilet that is safe and affordable for people in the developing world and does not have to be connected to a sewer. Eight universities were subsequently awarded grants to participate in what the foundation termed the “Reinventing the Toilet Challenge”.

Four hundred thousand dollars was allocated to KwaZulu-Natal University’s Pollution Research Group, which is led by Professor Chris Buckley, recognised around the world as one of the leading innovators of “off the grid” sanitation.

Ruth Cottingham, who was hired to lead the project, said the team, which is working with several partners including eThekwini Water and Sanitation and Envirosan, has been focusing on three key areas.

One involves designing operations for processing faeces and urine. “For the faeces, this includes drying and combustion processes to recover useful energy and turn potentially hazardous material into inert products. In the case of urine, the aim is to extract clean water and useful nutrients.”

The redesign of the pedestal section of the toilet is also being examined. “It is a similar idea to urine diversion, except that we are trying to split the waste again, into faeces, urine, wash water and possibly also rubbish streams. Splitting the waste at source has benefits for the waste processing operations downstream, but the challenge is to retain a pedestal that provides a comfortable and effortless user experience.”

Another area of focus is the thermal, chemical and rheological [flow behaviour] properties of “input streams” into the toilet process.

According to Unicef, 2.6-billion of the world’s population use public, bucket or open latrines, if they use any at all. “Open defecation and the absence of safe water [and its safe disposal] for personal hygiene results in the transmission of disease within communities and to the general population at large. Disease includes skin infections, diarrheoa and worm infections,” said Buckley.

But how likely are people living below the breadline to spend money on a new toilet?

Cottingham said that for people to commit to using and maintaining a toilet and potentially contributing to its initial cost, “it has to be something they want to own and use”.
“The vision of the ‘reinvented toilet’ is that it will be a product that will be able to compete with the flush toilet, which is currently the ‘gold standard’ of aspirational toilets — clean, convenient, ‘flush and forget,'” she said.

Buckley agreed. “It comes back to producing a solution that people aspire to have. We are looking at producing a toilet aimed at people whose disposable income is less than $2 a day. The valuable thing in their lives is safe drinking water and sanitation. The toilet which is envisaged would produce daily ‘wash water’ safely, it would give you acceptable water for house sanitation and could be private and have all the attributes of the toilet as you know it. It could also produce fertiliser and a certain amount of excess energy that could be used for lighting and to charge your cellphone. It would pretty much take hazardous material and turn it into something valuable.”

The team’s next reporting deadline is in August, when the Gates Foundation will host a “Toilet Fair” in Seattle.

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