As regulations and standards for water quality become more stringent across the country, cities and industries are looking for new options to treat water more efficiently, sustainably, and cost-effectively than ever before.
An Iowa-based startup has stepped up with an innovative solution that uses algae to remove pollutants from wastewater, then transforms the resulting biomass into a slow-release fertilizer, bioplastic and biofuels.
Gross-Wen Technologies (GWT) was founded in 2014 to commercialize the technology that was developed by Iowa State University graduate student Dr. Martin Gross and his major professor, Dr. Zhiyou Wen. Their technology is known as the revolving algal biofilm system (RAB), and is drawing interest from cities across the U.S. The RAB is not only effective at treating pollutants, it also provides a solution that can dramatically reduce the GHG emissions of wastewater treatment plants.
“Our customers are cities and food processing companies who are needing to upgrade water treatment systems to comply with changing quality standards,” said Gross, noting the company has worked with about over 40 cities and industries in Iowa, Wisconsin, Colorado, Illinois, Washington, Maine, Minnesota and Arizona to date. In 2023, GWT also deployed projects in Canada, France, Japan and Singapore.
“In order to sell wastewater treatment systems like we are developing requires significant data to meet regulatory approvals and standards. Many of our projects from 2014-2019 were pilot or demonstration projects designed to gather that data, develop models and standardize processes,” said Gross. “Beginning in 2020 we began deploying commercial projects throughout the U.S.”
Another benefit to cities installing the algae-based system is the elimination of expense to dispose of the bacteria or chemicals used in conventional systems to treat water. In fact, Gross-Wen will purchase back the algal biomass from cities in order to convert that biomass into slow-release fertilizer pellets or other valuable products.
Investing in Iowa for growth
Gross-Wen Technologies has created 20 full-time jobs and 4 part-time jobs and opened their headquarters in Slater, Iowa, in late 2019. In 2024 GWT expanded into a new office in downtown Des Moines and recently opened an operations and R&D facility in rural Boone County. The company has secured $20 million through both grant, debt and equity financing. Gross credits Iowa’s entrepreneurial resources and networks for helping move Gross-Wen from a lab-based technology to a successful startup company.
“As a native Iowan, I wanted to stay and build the business here,” said Gross. “Through all the activities and mentoring programs, I’ve been able to engage with a pretty impressive network of people that helped support our business, whether it is providing advice, make connections or help promote the business.”
Entrepreneurial resources for Iowa startups
Gross earned his undergraduate degree and PhD’s from Iowa State University, and also tapped into a number of entrepreneurial resources connected to the university.
“My background is in science and engineering; but I had never taken a business class,” he said. “The Start Something CALS Initiative, ISU Pappajohn Center, and ISU Startup Factory were great opportunities to train in areas needed to build, market and manage the business.
Gross-Wen Technologies was a member of the first ISU Startup Factory cohort, and also introduced Gross to a network of mentors. He noted that the company’s angel investor David Furbush was a mentor in the ISU Startup Factory program. The company is now part of the Ag Startup Engine, a private systematic program to fund AgTech entrepreneurs and help them towards success through mentorship and financial support. Later GWT received equity investments from the Rural Vitality Fund, Next Level Ventures, ISA Ventures and AiiM Partners.
After founding the company, Gross and Wen were awarded three USDA SBIR grants, which allowed them to further develop and validate the commercial use of their technology. Recently GWT has been awarded 3 US Department of Energy grants to develop sustainable aviation fuels out of the algae produced in their system.
Published October 2020, updated August 2024.