New wastewater treatment system runs on algae

[USA] Columbus Junction could count itself among pioneering cities in the struggle to treat wastewater if the city council approves new technology that favors algae over bacteria.

Wastewater treatment plants receive permits from the Iowa Department of Natural Resources that regulate what can be legally discharged into waterways.

When recent efforts to minimize pollution sparked the Iowa DNR to change standards for the amount of nitrogen and phosphorus that can be put into bodies of water, Columbus Junction found itself on a long list of small communities struggling to meet that demand.

The suggestions of engineers pitching conventional methods further disappointed Jeff Carey, wastewater operator in Columbus Junction, and city councilman Mark Huston.

“The engineers were proposing some things that were stupid and too much money,” Carey said. “And we knew that, and they knew that.”

That was when Carey called Gross-Wen Technologies to inquire about an alternative system, which Martin Gross, president and CEO of the company, said is more efficient, sustainable and affordable.

And, as Gross explained, it runs on “pond scum,” or, scientifically, algae.

Gross and co-founder Dr. Zhiyou Wen, developed the wastewater treatment system in 2011 while conducting research together at Iowa State University.

If approved by DNR, Columbus Junction could be the first town to receive a commercial installation system.

“I believe the city administration is very conscious of community tax dollars,” Gross said. “They are an innovative community looking for new ways to treat problems and are not scared of using innovative technologies to do so.”

If installed, Huston said the new system would cost Columbus Junction about $2.2 million, while using the conventional method would cost the city about $4.5 million.

While lower costs ease the minds of city officials, Gross said the process is also the most sustainable and environmentally friendly on the market.

The patent-pending revolving algal biofilm treatment technology, or RAB, grows micro algae on vertical belts that rotate in and out of the wastewater.

During the rotation, nitrogen and phosphorus are transferred from the wastewater to the algae. The algae also takes out ammonia and other contaminants from the wastewater.

Then, workers can harvest the algae from the system and use it to create products such as biofuels, bioplastics and fertilizers.

“Algae is beneficial because it takes CO2 out of the atmosphere and cleans the air while treating the wastewater,” Gross said.

While conventional treatments use bacteria, which becomes a waste product in the process, everything that comes out of the RAB system can be used.

The system would recover one ton of nitrogen and a half-ton of phosphorus from waterways each year, or, according to the Gross-Wen Technologies website, enough nutrients to grow 200,000 tomato plants.

The RAB systems are housed in small greenhouses, taking up less space than one-tenth of a football field.

Another perk, Gross said, is that algae can grow anywhere there is sunlight, making the success of this process possible nearly anywhere in the world.

Columbus Junction city officials met with the Iowa DNR on Aug. 15 to discuss the project. If approved, installation would take place next summer. In a press release, Columbus Junction Mayor Dan Wilson was hopeful the technology would be worth the investment.

“There is some apprehension, because we don’t know for sure,” Carey said. “We are 99 percent sure it is going to work and everything is going to go like the design and what they say, but we are the ones sticking our neck out on it.”

Huston agreed, but said the risk is one to take.

“If it gets approved, and it works, to be honest with you it will help a lot of communities if you can save roughly half the cost,” Huston said. “People think government pays for it, but government only gets their money from the people that are using it, so it’s a way to save your users some money and also comply with what the DNR wants.”

 

Photo: Inside a greenhouse, algae revolves on belts in and out of the wastewater. Columbus Junction is considering installing this system, developed by Iowa State University researchers, to treat its wastewater. [gross-wen.com]

View original article at: New wastewater treatment system runs on algae

 

 

 

 

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