Break

The current centralized domestic wastewater treatment paradigm principally involves aerobic wastewater treatment technologies, i.e., activated sludge. While effective in meeting U.S. EPA regulated discharge standards for organics and suspended solids, aeration of aerobic microorganisms is energy-intensive, typically accounting for ~50% of wastewater treatment facility costs. In total, wastewater conveyance and treatment accounts for a staggering 3% of our nation’s electrical energy usage. Anaerobic wastewater treatment is a viable methane-generating alternative to aerobic wastewater treatment. Anaerobic microorganisms convert wastewater organics (fats, carbohydrates, proteins, etc.) to methane, which can be harnessed to create electrical energy via technologies such as combined heat & power. If more electrical energy is generated from the methane produced than is used to run the process itself, then the process can be considered “energy-positive” (or a net energy producer). While promising, substantial research concerning anaerobic bioreactors remains in numerous areas, to include understanding how organic removal relates to methane generation. Further study of how particulate chemical oxygen demand (COD), soluble COD, and volatile suspended solids (VSS) relate to each other within anaerobic systems is also required. This study presents a statistical analysis of measured COD removal from two pilot-scale anaerobic baffled bioreactors operating for a total of > 2400 days in an effort to more completely understand the COD mass balance within the reactor system and relationships between organic measurement approaches (i.e., COD, dissolved organic carbon, and VSS).