Anaerobic co-digestion of sewage sludge and wine vinasse mixtures in single-stage and sequential-temperature processes

Abstract

The present work consisted of the energetic valorization of sludge from wastewater treatment plants and discharges from the wine sector by means of anaerobic co-digestion. The valorization was approached through the application of two different processes: a) single-stage mesophilic anaerobic digestion process (35 °C) and, b) Temperature - Phased Anaerobic Digestion (TPAD) with separation of microorganisms: thermophilic acidogenic (55 °C) and mesophilic methanogenic (35 °C) phases. Mesophilic methanogenic biodegradability tests (BMP) were developed to determine the biogas (methane) production yield in single-stage process and sequential thermophilic hydrogen (BHP) and BMP were developed to study the biogas (hydrogen and methane) production yield in anaerobic co-digestion processes in TPAD process. The results obtained showed that the single-stage mesophilic anaerobic co-digestion process was more effective for methane generation with yields of 55.39 mL CH4/g VSadded for the sludge and vinasse mixture, compared to 45.79 mL CH4/g VSadded for the TPAD process.