Researchers Claim Algae-Based Waste Treatment Saves

Researchers at Iowa State University claim their new wastewater treatment technology, which relies on algae, can benefit municipalities struggling to pay for treatment upgrades.

Zhiyou Wen, professor of food science and human nutrition, noted that these communities “are looking at upgrades to their existing treatment systems costing up to $5 million, which is a huge burden on these small towns,” according to the university.

New regulatory burdens often prompt the need for upgrades at treatment facilities.

“That’s the niche for us. We have this algae cultivation system that can help these communities meet their new nutrient limits at a fraction of the cost of other systems,” Wen said.

The researchers dubbed their new system the Revolving Algal Biofilm treatment system. Wen developed the system with Martin Gross, a postdoctoral fellow in the Center for Crops Utilization Research, according to Iowa State University.

Patent documents for this system describe it as an algal growth system comprised of “flexible sheet material, the flexible sheet material being configured to facilitate the growth and attachment of algae.”

“This reactor greatly improves the efficiency of carbon dioxide and sunlight absorption. We found that the biomass productivity is about 10 times higher than a conventional system,” Wen said.

A snapshot of the technology, per Iowa State: “The system uses vertical conveyor belts, about 6 feet tall and three feet wide, which revolve in a continual loop, cycling through the wastewater and air as multiple layers of algae grow on them...The algae produced from this new process can be harvested, pelletized and used as a sustainable fertilizer.”

The Metropolitan Water Reclamation District of Greater Chicago tested the system in a year-long study. “Promising results” prompted the district to extend the project another year, according to the university. The inventors also built a mobile version of their system to take on the road.

“Instead of inviting a local community’s water treatment personnel to come to our facility to perform water treatment tests, we built this trailer to take to the community to treat wastewater onsite,” Wen said.

The researchers secured investments to help them get their business off the ground, according to the university.

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