Produção de biogás através da co-digestão de resíduos orgânicos com bagaço de malte

Abstract

Organic solid waste accounts for more than 50% of the total urban solid waste produced in Brazil, thus requiring sustainable solutions to reduce its socio-environmental impact. This work evaluated the use of anaerobic bioreactors in biogas production from residues of malt bagasse from a brewery and food waste from the University Restaurant (UK) of the Federal University of Ceará (UFC). Two crushed mixtures are prepared, one consisting of RU residues associated with an inoculum-anaerobic sludge taken from an Upflow Anaerobic Sludge Blanket (UASB) reactor, from the Acarape III Sewage Treatment Plant (ETE) and Ceará Sewage (CAGECE) - and the other one composed of 50% residue of the bagasse and 50% organic residue from the RU associated to the anaerobic sludge. The anaerobic sludge was first separated into two 600 mL samples. Subsequently, a 300 gram sample of UK waste associated with 600 mL of sludge was added to a bioreactor, designated B1. A second bioreactor, designated B2, was added another sample containing 300 grams of malt bagasse associated with 300 ml of slurry. The processes of anaerobic digestion in bioreactors B1 and B2 lasted ten weeks, during which time five measurements of biogas produced to measure the volumetric fraction of methane were carried out. The bioreactor B1 presented a low production of the methane gas - 7.2% - The bioreactor B2 presented a much more expressive percentage, reaching the level of 48.3%. The experiments were able to reproduce large-scale operational conditions - landfills -, making it possible to increase the results for improvements in biogas capture and processing in landfills, strengthening sustainability. The experiments also showed the importance of studying different organic residues, seeking to optimize the process of anaerobic biodigestion, besides giving a sustainable solution to organic waste.