SEPARATE DIGESTION OF LIQUID AND SOLID FRACTIONS OF THERMALLY PRETREATED SECONDARY SLUDGE. ASSESSMENT AND GLOBAL EVALUATION
AUTOR(ES)
Pérez-Elvira, S. I., Sapkaite, I., Fdz-Polanco, F.
FONTE
Braz. J. Chem. Eng.
DATA DE PUBLICAÇÃO
2016-12
RESUMO
Abstract The fractioning into separate liquid and solid fractions obtained by centrifugation of thickened fresh and thermally pretreated (170 ºC, 50 minutes) secondary sludge showed that 30% of the particulate organic matter was released during the pretreatment, correspondingly increasing the methane production of the particulate matter by 30% (from 259 to 329 mL CH4/g VSfed). The responsible of this enhancement was the liquid fraction, as the biodegradability of the solid fraction remained constant after the pretreatment. Mass balances showed that 34% of the VS were released to the liquid fraction, generating nearly 50% of the total methane produced, with much faster kinetics compared to the solid fraction. These results support the hypothesis of a separate liquid-solid digestion of thermally pretreated sludge, which would result in decreasing the digestion volume to half while duplicating the methane productivity per kilogram of sludge fed to digestion.
