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Updated: Aug 7, 2025
Evaluation of Integrated Anaerobic Digestion and Hydrothermal Carbonization for Bioenergy Production
Published on: June 15, 2014
Thermal hydrolysis pre-treatment has no positive influence on volatile fatty acids production from sewage sludge
Ander Castro-Fernandez1, Anton Taboada-Santos2, Sabela Balboa3
1CETAQUA, Water Technology Centre, A Vila da Auga, José Villar Granjel 33, E-15890, Santiago de Compostela, Spain; CRETUS Institute, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain.
Abstract:
The study compares the potential to produce volatile fatty acids (VFA) from sewage sludge, both raw and thermally pre-treated in two modes of operation. In batch mode, raw sludge at pH 8 obtained the highest maximum VFA yield (0.41 g COD-VFA/g CODfed) whereas pre-treated sludge achieved a lower value (0.27 g COD-VFA/g CODfed). The operation of 5-L continuous reactors showed that thermal hydrolysis pre-treatment (THP) did not have any significant influence on VFA yields, averaging 15.1 % g COD-VFA/g COD with raw sludge and 16.6 % g COD-VFA/g COD with pre-treated one. Microbial community analysis showed that phylum Firmicutes was predominant in both reactors and that the enzymatic profiles involved in VFA production were very similar regardless of the substrate fed.
