Evaluación de la co-digestión anaerobia de lodos de aguas residuales municipales con residuos de alimentos/Anaerobic co-digestion of municipal sewage sludge with food waste/Avaliação do co-digestão anaeróbia de lodo de esgotos locais com resíduos dos alimentos

Anaerobic digestion is a process widely used for the treatment of sludge generated during wastewater treatment, due to its technical and economic advantages. This paper presents a study in which the co-digestion of sewage sludge with food waste (FW) was evaluated as a strategy for optimizing the digestion of sludge. Mono-digestions and co-digestions of the substrates were performed under mesophilic conditions (35°C) using batch reactors. The sludge used were: primary sludge (PS), thickened secondary sludge (TSS), and a mixture of PS with TSS in a ratio 60:40 based on total solids (PS:TSS). The co-digestions were performed using different ratios of mixtures of the substrates based on total volatile solids: PS:FW=30:70, PS:FW=50:50, PS:FW=70:30 y (PS+TSS):FW=70:30. The maximum methane yield, 0,25LCH4/gVSadded, was obtained for the mixture PS:FW=30:70, showing a yield 32% higher than the one obtained in the mono-digestion of PS.