The scope of our research is to use respirometry to examine the biokinetics of anaerobic microbiota co-digesting organic waste streams such as wastewater sludge and food scrap. We attempted to answer the question of how different substrate concentrations influence the rate at which these anaerobic microbiota produce methane. While several studies have measured methane production from co-digestion of waste-activated sludge coupled with other organic substrates such as a biowaste, fats, oils, grease, and agricultural waste, this research presents a respirometer protocol using a mix of dilute wastewater, waste-activated sludge, and food scrap waste as substrates.
Similar studies use batch assays in serum bottles where methane production is measured at discrete points throughout the experiment, while others use flow meters connected directly to bench or pilot scale bioreactors. Our protocol uses a respirometer that provides continuous and precise methane measurements from samples run in different experimental conditions.