Mesophilic versus thermophilic digestion of sludge in anaerobic membrane bioreactors
Amr Mustafa Abdelrahman (Universiteit Gent, Istanbul Technical University)
Saba Aghdam Tabar (Istanbul Technical University)
Busra Cicekalan (Istanbul Technical University)
Safak Basa (ISKI Istanbul Water and Sewerage Administration)
Gulin Ucas (ISKI Istanbul Water and Sewerage Administration)
Huseyin Guven (Istanbul Technical University)
Hale Ozgun (Istanbul Technical University)
Izzet Ozturk (Istanbul Technical University)
Ismail Koyuncu (Istanbul Technical University)
Jules B. van Lier (TU Delft - Sanitary Engineering)
Eveline I.P. Volcke (Universiteit Gent)
Mustafa Evren Ersahin (Istanbul Technical University)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Energy-efficient wastewater treatment plants (WWTPs) utilize systems like high-rate activated sludge (A-stage) system to redirect organics from wastewater are redirected into energy-rich sludge (A-sludge). Anaerobic membrane bioreactors (AnMBRs) offer lower footprint and higher effluent quality compared to conventional digesters. In this study, the biological treatment and the filtration performances of AnMBRs for A-sludge digestion under mesophilic and thermophilic conditions were comparatively evaluated through lab-scale experiments, mass balancing and dynamic modeling. Under thermophilic conditions, a higher COD fraction of the influent sludge was converted into methane gas than under mesophilic conditions (65% versus 57%). The energy balance indicated that the surplus energy recovery under thermophilic conditions was less than the additional energy required for heating the AnMBR, resulting in a more than three-fold higher net energy recovery under mesophilic conditions. Therefore, operating an AnMBR for sludge digestion under mesophilic conditions has a higher potential to improve the energy balance in WWTPs.