BRATTLEBORO — For the past 10 years, the Rich Earth Institute has been a pioneer and advocate for the conversion of urine into fertilizer.
The nonprofit Rich Earth Institute conducts research, education, and demonstrations of urine nutrient recycling, largely focused on community-scale and home scale implementation. In Brattleboro, it collects and processes urine and converts it for use on local farms, replacing over 500 pounds of commercially produced nitrogen fertilizer every year.
“Once people know the science of how we can reclaim these nutrients for beneficial reuse and how destructive it is for our environment the systems that we’re using now, then they usually can jump on board with this,” said Kim Nace, who cofounded Rich Earth with Abe Noe-Hays. “The science is clear as can be on that, that we need to move in this direction, because our current systems are bad, and they’re antiquated.”
Urine contains most of the plant nutrients found in human waste, including nitrogen and, especially, phosphorous, which is in limited supply around the world. In current waste treatment systems, phosphorous is flushed down the toilet when it can be reused in agriculture.
“You could grow wheat for a loaf of bread every single day with the urine you and I and each one of us flushes down the toilet,” said Nace.
And since the invasion of Ukraine, which has been characterized as the “Breadbasket of Europe,” inflation has driven up the cost of fertilizer and more people are paying attention to the work being done by folks such as Nace and Noe-Hayes. In fact, Rich Earth was recently featured in the New York Times, and CBS Sunday Morning will be in town in late August, as well.
“We represent sort of a hub of information and we’re trying to make sure people who are in this field keep talking to each other and finding each other and knowing who’s doing what next,” said Nace.
Recently, Rich Earth formed a spinoff, Brightwater Tools, a for-profit company that was a recipient of a $1 million grant from the National Science Foundation’s Phase II Small Business Innovation Research program.
In the next two years, the team will build, test and install a minimum of three units of a novel, building-scale, high-strength wastewater treatment system.
In conventional waste systems, toilet streams are combined with all other domestic wastes from showers, sinks, and washing machines, as well as industrial manufacturing waste. Wastewater treatment systems then remove pathogens but often still release both nutrients and contaminants into the watershed, with harmful ecological ramifications.
Rather than combining all these waters into one stream, Brightwater’s technologies separate out and recycle the “toilet resources.”
The system uses novel technologies necessary to stabilize, concentrate, sanitize and filter high strength wastewater. It will be deployed in multi-story buildings in both urban and rural settings.
Source-separating bathroom fixtures like waterless urinals, urine-diverting toilets, and vacuum-flush toilets will direct the waste through dedicated plumbing to a compact building-scale processor, which converts it into a liquid fertilizer.
The Rich Earth Institute has developed a computer-controlled pasteurizer with a high-efficiency heat exchanger to sanitize urine quickly and energy-efficiently. High temperature composting and ultraviolet exposure are methods that may also be suitable for sanitizing large volumes of urine.
Nace said they are looking at three locations to test their new technology — Seattle, the Netherlands, and here in Brattleboro.
“We’re going to have what’s called an alpha unit over at our research center [on Old Ferry Road],” she said. “That will be happening by the end of 2023. We’ll be able to use the urine that we collect in our urine nutrient reclamation project as the feedstock. But I know there’s a bunch of apartments being discussed around town and I’m really eager to get one of these really good systems installed.”
Working with an organization in the Netherlands, Brightwater is developing a “black water” system that separates toilet water from grey water.
The toilet water goes into a holding tank called a digester where the solids are treated with bacteria and the liquid is removed for conversion into fertilizer.
“We don’t take the urine out of the black water,” she said. “You take all the toilet water and first it goes into a digester. And then at the top of the digester is this nutrient rich effluent. It’s high strength wastewater and it contains almost all of the nutrients.”
In Brattleboro or Windham County they hope to connect with developers to install a water and nutrient recapture system in a new apartment building.
In an older building, Brightwater would have to decouple the black water from the grey water and disconnect it all from the sewer system, said Nace.
“If it’s new construction, we never have to connect to the sewer in the first place. All the other grey water — the shower water, the sink water, the washing machine water — that can all be combined into a flow that can then be treated to be used right on site.”
Another option is to install toilet units just for urine, said Nace.
“It’s a much easier treatment process than if you combine it with human waste,” she said.
Nace said one of the things they were concerned about when they first started Rich Earth was pharmaceuticals in the waste stream.
“We’ve done years of field trials and done a lot of quantification with the University of Michigan and the University of Buffalo,” said Nace. “There’s a lot of academic papers out now about what we’ve done. It’s a very small amount that gets through to the plant tissues when you use our fertilizer.”
In the new system that is being developed, there is charcoal filtration that removes particles such as pharmaceuticals, she said.
“Since the New York Times article, we’ve had about 80 people show up for each of our events. They’re coming from all over the world and all around the country to learn the details.”
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