A Case Study of Using a Revolving Algal Biofilm (RAB) Treatment System to Treat Anaerobic Digester Effluent at Pilot Scale

The Revolving Algal Biofilm (RAB) is currently being piloted in Ames, IA to recover nutrients from anerobic digestion effluent. Typically, the nutrient rich anaerobic digestion liquid stream is circulated back to the front-end of the wastewater treatment plant for treatment, these nutrients eventually make their way back to the anaerobic digester making an endless cycle. Adding the RAB system to treat AD effluent allows for that cycle to be broken. Algae produced during treatment can be sold as a fertilizer or ingredient for bioplastics. The removal of phosphorus from the AD effluent can help reduce the buildup of struvite.