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For the past several years, detergents and agricultural runoff have turned Logan's five wastewater lagoons into a phosphate-filled soup, posing a menace to sensitive wildlife habitat downstream and racking up costly clean-up bills.
But nature could be coming to the rescue in the form of green slime.
A collaborative project between the city and the Utah State University Research Foundation will use the ponds to grow algae, which might not only fix the phosphate problem for little money but produce energy. The city has won a $500,000 state grant to begin converting the 460-acre lagoon complex into an algae farm as a small-scale pilot project..
Although it can wreak environmental havoc, phosphorus is a key nutrient
"It's like killing two birds with one stone," said Paul Israelsen, a research associate professor in USU's electrical and computer engineering department. The algae cultivated in the lagoons is to be converted to methane and used as fuel for electrical generation and the phosphorus would be extracted to sell to fertilizer manufacturers and other industries.
Issa Hamud, Logan's environmental director, said the city was spending at least $250,000 every year to aerate the lagoons to prevent algae growth and was facing the prospect of building a $180 million treatment facility as a permanent solution to the phosphorus problem.
"Our hope is it will not only help Logan
The project is the brainchild of the USU Energy Dynamics Laboratory (EDL), where Israelsen is director of energy systems, and Ron Sims, another USU professor. EDL is the research foundation's newest division, one whose projects build on research by USU teams affiliated with the Utah Science, Technology and Research initiative. One of those USTAR teams is exploring ways to cultivate algae as a commercially viable source of biofuel.
"USTAR is doing foundational research and early-stage development. The [algae lagoon] project is a great example where an applied project and deliverable technology occurs because of the research we're doing," said biofuels team leader Jeff Muhs. The USTAR group is experimenting with small-scale "bioreactors" that grow algae in open and enclosed environments. The wastewater project will build on the team's ideas but on a much larger scale that will shed new light on algae potential as the fuel of tomorrow.
"It's a natural progression of a scale-up of the technology. Every time you scale up you find new issues," said Muhs. The grant will pay for the construction of raceways in which to grow and harvest algae. Researchers are trying to determine whether to use algae species that naturally grow in the lagoon or import species that USTAR researchers have identified as the fastest growing and with the highest lipid content.
Logan's wastewater lagoon system, one of the nation's largest and serving most of the Cache Valley, discharges 14 million gallons a year into Cutler reservoir and the Bear River drainage, ultimately flowing into the cherished migratory bird refuge on the Great Salt Lake. The algae project is believed to be first of its kind at a sewage treatment facility and could become a model for phosphorus-mitigation at the nation's 16,000 wastewater lagoons, officials say.
"Other municipalities will get hit with this same problem," Israelsen said. "It's just that Logan's is one of the largest and it happens to drain into an active recreational area downstream."
The EDL, like its more established sister divisions associated with space, seeks to prove USU-developed technologies and take them to marketplace when they become commercially viable. The algae project is its inaugural program.
"Clean, alternative and renewable energy is an ever-growing need," said Doug Lemon, interim director of EDL. Lemon anticipates spinning off a for-profit enterprise to market the algae-growing system should it prove successful.
"We can take those technologies to the marketplace with a little more agility than if we were a nonprofit," Lemon said. "We want to create jobs and it brings revenue back to the foundation."
