Full-Scale Field Research and Demonstration of Septage Bioreactor Landfill Technology

A septage bioreactor landfill was constructed and operated at a publicly owned landfill in the U.S. state of Michigan. Residential septage was processed onsite and injected into municipal solid waste (MSW) using subsurface injection lines (for supernatant) and surface infiltration pits (for sludge) to accelerate the solid waste-decomposition process. For comparison, a leachate bioreactor landfill was also constructed and operated onsite. By comparing the system performance from both bioreactors, the impact of septage addition was identified. Extensive datasets consisting of parameters such as waste temperature, waste-moisture content, leachate quality, landfill gas generation, and waste settlement were systematically evaluated. The waste temperature in both bioreactors was in accordance with a similar trend. Using leachate addition, the waste-moisture content in the leachate bioreactor was controlled to maintain similar moisture content as the septage bioreactor. Using a first-order decay model, the gas-generation rate coefficients (first-order decay coefficient) were estimated at 0.296 and 0.082 year−1 for the septage bioreactor and leachate bioreactor landfills, respectively. This project demonstrated that waste-decomposition rate can be accelerated by septage addition and septage can be processed and treated in the septage bioreactor safely and effectively.