Optimization of the hydrolytic-acidogenic anaerobic digestion stage (55ºC) of sewage sludge : influence of pH and solid content
Ponsá Salas, Sergio (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)
Ferrer, Ivet (Universitat Politècnica de Catalunya. Escola Tècnica Superior d'Enginyeria Industrial de Barcelona)
Vázquez Lima, Felícitas (Universitat Autònoma de Barcelona. Institut de Biotecnologia i de Biomedicina "Vicent Villar Palasí")
Font i Segura, Xavier (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)

Date:	2008
Abstract:	In conventional single-stage anaerobic digestion processes, hydrolysis is regarded as the rate-limiting step in the degradation of complex organic compounds, such as sewage sludge. Two-stage systems have been proposed to enhance this process. However, so far it is not clear which are the best conditions for a two-stage anaerobic digestion process of sewage sludge, in terms of temperature and hydraulic retention time of each stage. The aim of this work was to determine the optimal conditions for the hydrolytic-acidogenic stage treating real sludge with a high concentration of total solids (40-50 g L⁻¹) and volatile solids (25-30 g L⁻¹), named high concentration sludge. The variables considered for this first stage were: hydraulic retention time (1-4 days) and temperature (55 and 65 °C). Maximum volatile fatty acids generation was obtained at 4 days and 3 days hydraulic retention time for 55 °C and 65 °C, respectively. Consequently, 4 days hydraulic retention time and temperature of 55 °C were set as the working conditions for the hydrolytic-acidogenic stage treating high concentration sludge. The results obtained when operating with high concentration sludge were compared with a low concentration sludge consisting of 17-28 g L⁻¹ total solids and 13-21 g L⁻¹ volatile solids. The effect of decreasing the influent sludge pH, when working at the optimal conditions established, was also evaluated.
Grants:	Ministerio de Ciencia y Tecnología REN2002-00926/TECNO
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Anaerobic digestion ; Hydrolysis-acidogenesis ; Thermophilic ; Two-stage process ; Volatile fatty acids ; Waste sludge
Published in:	Water research, Vol. 42, Issue 14 (Aug. 2008) , p. 3972-3980, ISSN 0043-1354

DOI: 10.1016/j.watres.2008.07.002

Pre-print 21 p, 1.5 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut de Biotecnologia i de Biomedicina (IBB)
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Engineering > Composting Research Group (GICOM)
Articles > Research articles
Articles > Published articles