CODIGESTION OF LIVESTOCK AND AGROINDUSTRIAL WASTE IN CSTR TYPE REACTORS

The consumption of animal proteins has been increasing in recent years, leading to accelerated growth in production and, as a consequence, greater generation of waste with a high content of organic matter. Therefore, it is necessary for technologies and processes to emerge to reduce production costs and optimize production processes, but without neglecting the large volume of waste generated, which must be correctly managed. Along with agro-industrial processes, there are the processing stages of different proteins within the gate, which are also inherent generators of waste that require treatment, mainly seeking alternatives in which the waste does not need to be transported over long distances or can be worked on in the place where it is generated. One of the treatment alternatives, already used in the country for a few decades, is anaerobic digestion (AD), which provides efficient removal of organic matter; enabling these residues, after treatment, to generate biogas, and digestate that has potential use in the form of biofertilizer. The project in question treated five different substrates (waste) arising from livestock activities (cattle manure, swine manure and poultry hatchery residue) and agro-industrial activities (protein residue and dry sludge from a Dissolved Air Flotator (FAD)), in a biodigester of the Continuous Stirred Tank Reactor (CSTR) type, on a laboratory scale, and simulated conditions in which waste is transported to this unit. Various mixing conditions for these different substrates were studied in the reactor, that is, an anaerobic co-digestion process, simulating the best operating conditions depending on the availability of the waste to be processed.