Caitlyn Shea Butler, professor of civil engineering at the University of Massachusetts, has invented what she calls the “green latrine.” It processes human waste, makes compost for use on growing crops and even generates a little bit of electricity. Her invention has been profiled on the universities News and Media Relations site. Mother Nature Network explains that composting toilets aren’t nearly as gross as they sound and have been found to be very useful for some people in the United States, but more importantly for those in places, such as some parts of Africa, where treatment of human waste isn’t an option.
Composting toilets treat human urine and feces, removing the parts that can cause disease, such as diarrhea, and output material that is safe to use as fertilizer for plants grown for consumption, according to Mother Nature Network, and have become a popular alternative for people in the United States who wish to avoid adding to the tons of nitrogen that now make their way into the countries water systems, oftentimes choking the life out of them. Butler’s objective was far different, her goal was to create a toilet that could be used by people in Ghana, a place she visited last year. While there she found that most of the people who lived in villages simply dug holes that were used as a latrine. The problem was, the waste seeped down into their wells and caused disease in the people who consumed the water from them.
Her Green Latrine works by first accepting human waste into a bin that has electrodes attached to it. As the material decomposes, it mixes with nitrates in the air which causes an electrical charge. That charge is then routed out the system via the electrodes. By allowing the electrons to be released, the bacteria in the material is killed as the material oxidizes. In effect, it’s burned away, leaving organic matter that is free of the bacteria that normally reside in the human gut. That makes it safe for use as a fertilizer on crops used as a food source. What’s more the small amount of electricity generated is just enough to run light bulbs in the latrine housing, so that it can be used at night as well.
Butler has already brought a prototype of her new latrine to a village in Ghana for field testing, and thus far, has shown very promising results. She’s also received some funds from the Gates foundation to help in finding a company to begin producing the Green Latrine in bulk, and then donating them to villages throughout Africa.