External Carbon Storage and Feed System to Accommodate Alternative Carbon Substrates at the Blue Plains AWTP: Challenges and Remedies to Handle Glycerol

Design of the Enhanced Nitrogen Removal Facility (ENRF) at DCWater's Blue Plains Advanced Wastewater Treatment Plant (Blue Plains) has been recently completed. The carbon facility designed as part of this project will be country's largest wastewater treatment plant carbon facility and is designed to handle methanol and other alternative carbon substrates including waste glycerol from the biodiesel industry. Methanol was selected as the base carbon source and glycerol was selected as the preferred alternate carbon. Dilution with methanol was found to be the solution to deal with the freezing and viscosity concerns related with glycerol storage and feed. Blending with methanol also offers other process benefits such as maintaining high COD value. More importantly, it also helps sustain the active methylotrophic population in the denitrifying biomass. Details of the process and mechanical design will be discussed in the paper.