A Novel Approach to Wastewater Treatment

Gross-Wen Technologies Shows Promise, is Poised for Growth

While most look across an algae covered pond and see a mess, Dr. Martin Gross and business partner Dr. Zhiyou Wen see magic.

That is because the two, who founded Gross-Wen Technologies (GWT) in 2013, have developed a system that uses algae to treat wastewater. The process is being piloted at a handful of wastewater treatment plants scattered across Iowa and the Midwest, varying in scope from a relatively small operation in Dallas Center, Iowa, to the Metropolitan Water Reclamation District of Greater Chicago. That district treats 1.5 billion gallons of water from the city and its outlying suburbs each day, making it the largest wastewater treatment division in the world.

Gross is hopeful that the technology developed at Iowa State University will soon gain wide acceptance across the United States.

“We are working on pilot-scale validation right now and we have been encouraged,” Gross says. “We are looking to expand within Iowa first and then regionally. We plan to focus on smaller communities initially, but we have an eye out for opportunities in larger municipalities, similar to the project we are involved with in Chicago.”

Value Added Product

GWT’s algal based wastewater treatment process recovers nutrients such as nitrogen and phosphorus from wastewater. With the patent-pending technology, called the Revolving Algal Biofilm Treatment System (RAB), algae grows on a series of belts that cycle through the wastewater, pulling out the pollutants. The process is carbon negative, and the collected biomass can be transformed into a value-added product.

“During treatment we take CO2 out of the atmosphere, and then convert that CO2 into algal biomass that is used to make a slow-release algal fertilizer,” Gross says. “The algae biomass has the potential for making biofuels and bioplastics as well.”

Conventionally, wastewater is treated with a combination of chemicals and/or bacteria. The resulting waste that can be a challenge to dispose of.

The transformed GWT waste product has market appeal for farmers and home gardeners.

Gross says the GWT pelletized fertilizer can be applied to crops, providing a slow release of nutrients vital to the crop growing process, including nitrogen and phosphorus. Due to the nature of the algae fertilizer, there is a greatly reduced risk of the nitrogen and phosphorus running off into streams or rivers.

The fertilizer is a bonus the GWT team stumbled upon in the development process. In fact, when Gross first started working with algae, treating wastewater wasn’t even on the table.

“Our process for growing the algae is what is novel,” Gross says. Most algae is grown suspended in water. Gross and Wen developed a process that made it possible to grow algae on film in 2011 at Iowa State University. “Our initial work was on developing algae to be used in making biodiesel.”

Mass Appeal

Shifting to wastewater treatment has GWT poised for rapid growth. The pilot project in Dallas Center, along with another in Ames, Iowa, represent opportunities to show how the system can be effective in the smaller water districts common across Iowa—and the Midwest. With government regulations growing more stringent and smaller treatment plants growing older, Gross says the GWT solution is perfect.

And the major differentiator of the GWT technology, its vertical orientation of the product, means it uses far less space than conventional algal treatment systems. That is an attractive characteristic for smaller plants.

“Our system can be retrofitted to about any type of wastewater treatment plant,” he says. “Dallas Center is one of about 700 plants of its kind in Iowa that could benefit from our system. There are so many advantages, from the relatively low cost of implementation when compared to building a new plant, to the fact that there really isn’t any additional staff needed to run the system.”

Gross says that the GWT system is fully automated and no one needs to be at the plant for it to work. There are regular audits that need to be done to ensure it is functioning properly and the belts need to be harvested once a week. He says these tasks could be managed by a single staff member overseeing the operation of a handful of plants. Additionally, redundancy is built in to the system so if one of the belts experiences issues, the rest pick up the slack and continue to treat the wastewater.

An Encouraging Investment

Gross says that while his team was confident while developing the technology in the lab, the business side proved intimidating. It wasn’t until GWT landed in the first cohort of the Iowa State University Startup Factory in 2016 that plans for growth really began to accelerate.

“Going in, we were a team of engineers and scientists trying to build a business,” Gross says frankly. “The Startup Factory provided us with the skills to begin to grow as a business, not just a technology. It pushed us out of our comfort zones to do things we probably wouldn’t have done otherwise.”

Among those things was seeking investment. Which they found in relatively short order.

Des Moines investor Dave Furbush, a vice president of Midwest Project Partners, personally invested $225,000 in GWT. Furbush is a volunteer business coach at the ISU Startup Factory.

“We are so thrilled to have this strategic partnership with Dave,” Gross says. “Not only is Dave a tremendous strategic thinker and dynamic implementer, he has been a fervent supporter of water quality ever since he wrote a middle school paper on the 1972 Clean Water Act. That shared passion, along with his great business experience working with a vast number of companies, will prove to be very advantageous to our startup company.”

Furbush is excited to see the impact GWT will have on water quality.

“I’ve been interested in water quality ever since I was 14,” Furbush says. “I’m also a member of the Raccoon River Watershed Authority and have a home on Lake Panorama, where I watch with concern the algae bloom each August. Ensuring water quality in Iowa is very important to me. Naturally, I was very interested in what GWT offers. In addition, Martin and his partners are quality individuals.

“I knew I was interested in potentially working with GWT in July [of 2016] when we were just getting started with the ISU Startup Factory,” Furbush continues. “Early on I could sense that Martin had what it takes to be very successful with this business.”

Gross said the investment capital will go a long way in helping GWT expand their business and increase their operational capacity. For example, $40,000 of the investment money along with $40,000 cost-sharing funds from Iowa State’s Center for Industrial Research and Service (CIRAS) will be used towards an $80,000 project to evaluate GWT’s technology and gain DNR regulatory approval. The project requires data to come from communities of differing sizes.

“We were great researchers, but the business development side was always lacking,” says Gross, who along with Wen, was joined by vice president Dr. Darren Jarboe in 2014 to form the core GWT team. GWT is set to add staff during 2017. “Getting into business development was a leap of faith, but the ISU Startup Factory has been invaluable in helping us to grow.

“It’s just awesome to look forward at what we can become,” Gross adds, “and know that it all started right here at Iowa State.”