An idea that’s been percolating on the Tampa campus of the University of South Florida for a decade is now being applied halfway across the world, just as its inventors imagined.
Daniel Yeh came up with the idea of a "resource-recovery machine” while he was working on his post-doctorate at Stanford University.
"So what that means is it converts the waste materials, either human waste or food waste, various types of wastewater," Yeh said. "We will convert that to beneficial products: nutrients, energy and water."
More importantly, the machine would work completely off-grid, meaning no outside water or power sources would be required.
"We’re mimicking what nature does very efficiently, but in a very compact, engineered system, so nothing goes to waste and everything is repurposed," he added.
Yeh came to USF in 2004 as an Assistant Professor in the Department of Civil and Environmental Engineering. He brought the concept with him and shared it with his graduate students.
"We went from basically just having an idea, making sketches on the board, to building prototypes in the lab and trying things out," Yeh said, adding that his students embraced his idea with fervor.
"I can tell you though the students are on this 24/7. We email each other until like 2 or 3 o’clock in the morning and the next morning at 6, 7, we’re back on it, so I don’t know when the students sleep," he said with a laugh.
The team eventually came up with a patented device they call the NEWgenerator – NEW being an acronym for the machine’s end products: Nutrients, Energy and Water.
The system is paired with a device with a sewage tank, like a portable toilet. The battery-run generator pulls waste and wastewater from the tank, then runs it though a membrane-based cleaning filter.
That draws out nutrients, as well as water that is then chlorinated for future toilet flushing.
For the moment, using the system to create drinkable water would be expensive, but it is something Yeh and his team are looking to do in the future.
The system is housed in a 5' x 8' x 8' shipping container. On the roof, solar panels recharge the generator’s batteries; on the side, non-edible plants contained in a row of pipes are sustained hydroponically, using the nutrients and chlorinated water.
"What we have here is lavender. It’s a very aromatic herb, so, you can create lavender oils, fragrances," USF environmental engineering doctoral student Jorge Calabria said, pointing to rows of the plants. "Underneath we have some chrysanthemums, they’re an annual flower plant. (We) thought it would provide a nice look. If we’re doing anything, we’re kind of improving the aesthetic."
The generator has drawn attention and, more importantly, funding, from a variety of sources. It beat out 85 other ideas to win a $50,000 prize from the Cade Museum in Gainesville last year. It also received a $100,000 grant from the Bill and Melinda Gates Foundation.
But the biggest prize came as a $200,000 award from the government of India, which has invited the group to field test it in the coastal city of Trivandrum (also known as Thiruvananthapuram) - an ideal place to put the system through its paces, according to the researchers.
"In the coastal community, part of the problem is flooding, so any sort of soil-based sanitation system, they end up flooding whenever the tide comes in," graduate research assistant Robert Bair said. "And so, septic tanks and a lot of conventional wastewater treatment facilities just don’t work in those areas."
"The government has provided facilities in the past, but most of them have failed, so we’re really hoping to fill that gap or need that they have for sanitation technologies there," Bair said.
(If Bair's name sounds familiar, University Beat profiled him previously as a member of "The Scientific League of Superheroes," a trio of USF engineering students who dress as superheroes and create science-based videos to teach local elementary school students.)
During the NEWgenerator testing, it is being paired with an eToilet - India's first electronic public toilet, near a school in a small fisherman's community in Kerala.
Working at full capacity, one generator can treat the wastewater from one hundred people per day. Its compact size can make a difference – four generators can fit into one full shipping container, which can be sent to an impoverished area, whether for daily use or in post-disaster humanitarian efforts.
The team is currently in India setting up the system. Bair will remain there for about a year to test and collect data and see how the equipment can be improved.
"When I first traveled abroad as a young child, I saw the conditions that a lot of people live and it really impacted me," Bair said. "I wanted to make an impact with some skillset and now as an engineer, I feel like I have a tangible skill set I can offer to other people and I feel like this project does exactly that."
And Yeh hopes that Bair’s observations will make it easier to eventually mass produce and market the NEWgenerator.
"We believe in this technology and now it is basically to put this in the right product form, find the right customers and really convince people that this will work," Yeh said.
And once the system can create clean water, it could be used in drought-stricken areas in the United States. But the team believes developing countries are the ideal place for the generator.
"I once heard somebody on a TEDTalk saying that there’s this thinking that poor people deserve poor solutions and that’s completely false. Poor people deserve solutions that work," Yeh said. "We know membranes work. Right now, it’s matter of how do we engineer the membranes into systems at a price point that we can get a system to work."