Gross-Wen Technologies (GWT), founded in 2016 and based in Des Moines, IA, is a leader in sustainable wastewater treatment. GWT’s core technology, the Revolving Algal Biofilm (RAB™) system is a novel approach to nutrient recovery from wastewater. Utilizing algae, the RAB system offers a more sustainable solution compared to conventional wastewater treatment techniques and does not require energy-intensive aeration and chemicals.

The RAB utilizes vertically oriented rotating conveyor belts that are semi-submerged in wastewater and exposed to sunlight. This creates the ideal environment for algae to grow and remove nutrients like nitrogen and phosphorous from wastewater naturally. The novel design of the RAB system has helped overcome challenges faced by conventional algae cultivation technologies. Embracing a circular approach, the algae is periodically removed from the system and used to create sustainable bio renewable coproducts such as fertilizers, soil amendments, bioplastics, and biofuels.

The RAB technology can be applied to both municipal wastewater treatment plants and industrial food and beverage facilities. The use of the RAB system at these facilities provides a reduction in the facility’s greenhouse gas footprint while simultaneously meeting their wastewater treatment needs. Today, GWT has three commercial-scale installations in operation, and is rapidly expanding with more projects in design and construction.