Big sub-Saharan issue being solved by small R.I. valve

PROVIDENCE COLLEGE featured physics professor Stephen Mecca's work to solve sub-Saharan Africa's chronic sanitation problem in its Fall 2011 edition. / COURTESY PC MAGAZINE: FALL 2011
PROVIDENCE COLLEGE featured physics professor Stephen Mecca's work to solve sub-Saharan Africa's chronic sanitation problem in its Fall 2011 edition. / COURTESY PC MAGAZINE: FALL 2011

The innovation that one day solves sub-Saharan Africa’s chronic sanitation problem could be sitting in physics professor Stephen Mecca’s Providence College lab.
It’s not a new computer program or biotech marvel, but a toilet valve that happens to flush with a small fraction of the water needed to operate a toilet here in the United States.
“We are excited and think we are getting there,” Mecca said about the new valve and its role in a prototype toilet design that he is helping test in the West African nation of Ghana. “We are waiting for something to go wrong and nothing has gone wrong yet.”
With three prototype toilets installed in May going strong, Mecca and his students are now working on the equally challenging task of scaling the technology up and bringing it to as much of Ghana and surrounding nations as possible.
“I think we have changed sanitation in the developing world, but the tough part is still ahead,” Mecca said.
The problem poor sanitation poses to quality of life in rural Africa is enormous.
According to a 2008 World Health Organization report, 45 percent of people in rural West Africa do not have access to any sanitation facilities. As a result, many in the area are highly vulnerable to disease and struggle to find clean drinking water.
“This has all kinds of problems for people, including in education, where children don’t come to school at high rates because they are sick,” Mecca said. “Out of a gross domestic product of $30 billion in Ghana, a few hundred million [dollars] are lost directly to poor sanitation.”
With a background in nuclear physics, Mecca’s involvement in rural sanitation began recently after his granddaughter co-founded the Ghana Sustainable Aid Project Mecca, a nongovernmental organization that promotes health, education and economic development in the village of Pokuase.
In 2009, Mecca took a sabbatical from PC to teach in Ghana and began working with a local engineer named Kweku Anno, who had developed a promising waste-digestion system that he was struggling to make work in functional toilets.
Anno’s anaerobic digestion system uses organisms to break down human waste into compost, but the prototypes he had put in the field did not have any barrier or flushing system between the waste digestion and the user. The result was powerful odors and an onslaught of flies common to basic systems such as pit latrines. Mecca decided that what was missing was an inexpensive flush system that functioned with the resources at hand. Common Western toilets, which use century-old technology, rely on large sewer systems and vast quantities of purified water not available in rural Africa.
When he returned to Providence, Mecca began working with student Colin MacDonagh on a valve that would operate with such a small amount of water it could be collected from rainwater and would not pose “downstream” wastewater issues.
What they came up with is a valve that can flush using about the amount of water in a coffee cup and is inexpensive to build.
One challenge was to build the valve without a lot of metal machine parts that could break or are not available in rural Ghana.
While that issue was addressed by casting pieces in concrete, another problem has been reducing the weight of the finished toilets so they can be easily transported on Ghana’s patchy rural roads.
So far, Mecca has overseen the construction and installation of three prototype facilities – a single-toilet, five-toilet and 10-toilet facilities – that use the Microflush Biofil technology he developed with Anno.
The systems work by collecting rainwater, which flows straight to the hand-washing sink. From the sink, the “gray water” is collected and used to flush the toilet, which operates on about 150 cubic centimeters instead of the 1 to 1.5 gallons in a Western toilet.
The waste from the toilet is then piped into a leaching field where it is digested by tiger worms, fly larvae and, possibly, a burrowing beetle that has looked promising in tests.
After 10 days, the waste is ready to be harvested as compost.
Intrigued by the toilet’s efficiency and low cost, people have talked to Mecca about the commercial potential of Microflush Biofil. But he is now totally focused on helping get it to those who could benefit the most.
To finance a large-scale toilet construction and installation project, Mecca and his team are looking at a cooperative model that would have those who use the system pay about 3 cents per day.
Ideally, the co-ops would be administered by a government revolving fund, but the prevalence of corruption has made it more likely a nonprofit will run it.
He expects to roll out a second generation unit in about six months.
“When people use our system, there are no flies and no odor. People don’t even believe it is a toilet,” Mecca said. •

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