Formation of aerobic granules for the treatment of real and low-strength municipal wastewater using a sequencing batch reactor operated at constant volume.

Autor: Derlon N; Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; Institute of Environmental Engineering, ETH Zürich, CH-8093 Zürich, Switzerland. Electronic address: nicolas.derlon@eawag.ch., Wagner J; Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; Federal University of Santa Catarina (UFSC), Department of Sanitary and Environmental Engineering, 88040-970 Florianópolis, Santa Catarina, Brazil., da Costa RHR; Federal University of Santa Catarina (UFSC), Department of Sanitary and Environmental Engineering, 88040-970 Florianópolis, Santa Catarina, Brazil., Morgenroth E; Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; Institute of Environmental Engineering, ETH Zürich, CH-8093 Zürich, Switzerland.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2016 Nov 15; Vol. 105, pp. 341-350. Date of Electronic Publication: 2016 Sep 09.
DOI: 10.1016/j.watres.2016.09.007
Abstrakt: This study aimed at evaluating the formation of aerobic granular sludge (AGS) for the treatment of real and low-strength municipal wastewater using a column sequencing batch reactor (SBR) operated in fill-draw mode (constant volume). The focus was on understanding how the wastewater upflow velocity (V WW ) applied during the anaerobic feeding influenced the sludge properties and in turn the substrate conversion. Two different strategies were tested: (1) washing-out the flocs by imposing high wastewater upflow velocities (between 5.9 and 16 m h -1 ) during the anaerobic feeding (Approach #1) and (2) selective utilization of organic carbon during the anaerobic feeding (1 m h -1 ) combined with a selective sludge withdrawal (Approach #2). A column SBR of 190 L was operated in constant volume during 1500 days and fed with real and low-strength municipal wastewater. The formation of AGS with SVI 30 of around 80 mL g TSS -1 was observed either at very low (1 m h -1 ) or at high V WW (16 m h -1 ). At 16 m h -1 the AGS was mainly composed of large and round granules (d > 0.63 mm) with a fluffy surface, while at 1 m h -1 the sludge was dominated by small granules (0.25 < d < 0.63 mm). The AGS contained a significant fraction of flocs during the whole operational period. A considerable and continuous washout of biomass occurred at V WW higher than 5.9 m h -1 (Approach #1) due to the lower settling velocity of the AGS fed with municipal wastewater. The low sludge retention observed at V WW higher than 5.9 m h -1 deteriorated the substrate conversion and in turn the effluent quality. High solid concentrations (and thus solid retention time) were maintained during Approach #2 (V WW of 1 m h -1 ), which resulted in an excellent effluent quality. The study demonstrated that the formation of AGS is possible during the treatment of real and low-strength municipal wastewater in a SBR operated at constant volume. Low wastewater upflow velocities should be applied during the anaerobic feeding phase in order to ensure enough biomass retention and efficient substrate removal.
(Copyright © 2016 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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