Long term operation of a thermophilic anaerobic reactor

The aim of this study was to evaluate the performance of thermophilic sludge digestion at decreasing sludge retention time (SRT) and increasing organic loading rate (OLR), in terms of methane production, effluent stabilisation, hygienisation and dewaterability. Focus was put on determining indicator...

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Bibliographic Details
Authors: Ferrer, Ivet|||0000-0002-4568-4843, Vázquez Lima, Felícitas, Font, Xavier|||0000-0003-4981-7436
Format: article
Publication Date:2009
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:163067
Online Access:https://ddd.uab.cat/record/163067
https://dx.doi.org/urn:doi:10.1016/j.biortech.2009.12.006
Access Level:Open access
Keyword:Biogas
Biosolids
Dewaterability
Hygienisation
Wastewater
Description
Summary:The aim of this study was to evaluate the performance of thermophilic sludge digestion at decreasing sludge retention time (SRT) and increasing organic loading rate (OLR), in terms of methane production, effluent stabilisation, hygienisation and dewaterability. Focus was put on determining indicators to help prevent process failure. To this end, a lab-scale reactor was operated for nearly 2 years at 55 °C. Methane production rate was increased (from 0.2 to 0.4-0.6 m³CH₄ m⁻³reactor d⁻¹) by decreasing the SRT from 30 to 15-10 days, while increasing the OLR from 0.5 to 2.5-3.5 kg VS m⁻³reactor d⁻¹. Sludge dewaterability was worsened at SRT below 15 days; while pathogen destruction was always successful. The following concentrations might be used to prevent process failure: VFA C2-C5 (3.7 g COD L⁻¹), acetate (0.6 g L⁻¹), acetate/propionate (0.5), intermediate alkalinity (1.8 g CaCO₃ L⁻¹), intermediate/partial alkalinity (0.9), intermediate/total alkalinity (0.5), CH₄ in biogas (55%).