Print Email Facebook Twitter Impact of the anaerobic feeding mode on substrate distribution in aerobic granular sludge Title Impact of the anaerobic feeding mode on substrate distribution in aerobic granular sludge Author Haaksman, V.A. (TU Delft BT/Environmental Biotechnology) Schouteren, M. (Student TU Delft) van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology) Pronk, M. (TU Delft BT/Environmental Biotechnology; Royal HaskoningDHV) Date 2023 Abstract There is a growing interest to implement aerobic granular sludge (AGS) in existing conventional activated sludge (CAS) systems with a continuous flow-through configuration. The mode of anaerobic contact of raw sewage with the sludge is an important aspect in the adaptation of CAS systems to accommodate AGS. It remains unclear how the distribution of substrate over the sludge by a conventional anaerobic selector compares to the distribution via bottom-feeding applied in sequencing batch reactors (SBRs). This study investigated the effect of the anaerobic contact mode on the substrate (and storage) distribution by operating two lab-scale SBRs; one with the traditional bottom-feeding through a settled sludge bed similar to full-scale AGS systems, and one where the synthetic wastewater was fed as a pulse at the start of the anaerobic phase while the reactor was mixed through sparging of nitrogen gas (mimicking a plug-flow anaerobic selector in continuous flow-through systems). The distribution of the substrate over the sludge particle population was quantified via PHA analysis, combined with the obtained granule size distribution. Bottom-feeding was found to primarily direct substrate towards the large granular size classes (i.e. large volume and close to the bottom), while completely mixed pulse-feeding gives a more equal distribution of substrate over all granule sizes (i.e. surface area dependant). The anaerobic contact mode directly controls the substrate distribution over the different granule sizes, irrespective of the solids retention time of a granule as an entity. Preferential feeding of the larger granules will enhance and stabilise the granulation compared to pulse-feeding, certainly under less advantageous conditions imposed by real sewage. Subject aerobic granular sludgeanaerobic selectorbottom-feedingcontinuous flowPHApulse-feeding To reference this document use: http://resolver.tudelft.nl/uuid:f51d51e1-7a30-4b5b-b905-acfe3e8740f1 DOI https://doi.org/10.1016/j.watres.2023.119803 ISSN 0043-1354 Source Water Research, 233 Part of collection Institutional Repository Document type journal article Rights © 2023 V.A. Haaksman, M. Schouteren, Mark C.M. van Loosdrecht, M. Pronk Files PDF 1_s2.0_S0043135423002385_main.pdf 8.53 MB Close viewer /islandora/object/uuid:f51d51e1-7a30-4b5b-b905-acfe3e8740f1/datastream/OBJ/view