Home > Articles > Published articles > A novel control strategy for enhancing biological N-removal in a granular sequencing batch reactor : |
Date: | 2013 |
Abstract: | Biological nitrogen removal in aerobic granular sequencing batch reactors is sensitively affected by process conditions (e. g. dissolved oxygen (DO) concentration, nitrogen loading rate (NLR), influent C/N ratio, among others). The variation of one of these process conditions affects the others, because often they are tightly linked. These interrelationships are a drawback for the experimental assessment of the target domain of process conditions required to enhance N-removal. Here, we have developed a model to determine the guidelines to design an automatic control strategy with the final aim of enhancing biological N-removal in a granular sequencing batch reactor. The model was first calibrated with experimental data from a granular sequencing batch reactor treating swine wastewater. Specific simulations were designed to elucidate the effect of DO concentration (0. 5-8 mg O₂ L⁻¹), granule size (0. 5-3. 5 mm), influent C/N ratio (4-10 g O₂g⁻¹ N) and NLR (0. 41-0. 82 g N L⁻¹ d⁻¹) on the nitrification- enitrification efficiency. Simulation results showed that, in general, high N-removal efficiencies (from 70% to 85%) could be obtained only setting the appropriate DO concentration. That appropriate DO concentration could be easily found based on effluent ammonium concentration. Those results were used to propose a control strategy to enhance N-removal efficiencies. The control strategy was based on a closed DO loop with variable DO set-point. The DO set-point was established at a constant value for the whole cycle (i. e. once per cycle), based on the on-line measurement of ammonium concentration at the end of the previous cycle. |
Grants: | Ministerio de Economía y Competitividad CTQ2008-06792-C02-02/PPQ Ministerio de Economía y Competitividad CTQ2011-24745/PPQ |
Rights: | Tots els drets reservats. |
Language: | Anglès |
Document: | Article ; recerca ; Versió acceptada per publicar |
Subject: | Aerobic granular sludge ; Dissolved oxygen concentration ; Mathematical modeling ; Nitrification-denitrification ; On-line ammonium concentration ; Particle size |
Published in: | Chemical engineering journal, Vol. 232 (Oct. 2013) , p. 468-477, ISSN 1873-3212 |
Post-print 40 p, 1.2 MB |