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Start-up Analysis of a Partial Nitrification Aerobic Granular Sludge System Treating High-Strength Municipal Digestate Supernatant
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- Author / Creator
- Levicek, Rebecca Dina
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Ammonia pollution is a growing environmental concern affecting wastewater treatment. With rising concerns about energy consumption and increasingly strict discharge regulations, mitigation of energy expenditure and maintenance of high pollutant removal efficiency have fueled advances in biological wastewater treatment. Partial nitrification AGS-SBR technology has shown potential in treatment efficiency and versatility especially under high pollutant loading. However, neither microbial development nor large-scale operation of such systems has yet been tested. This study therefore focused on identification of changes in microbial community over the course of AGS reactor start-up on a laboratory scale under conditions of increased ammonia loading, and the subsequent operation of pilot scale partial nitrification AGS reactors. The study found that ammonia removal remained above 90% for most of laboratory scale operation with efficiency falling at increased ammonia concentrations. Despite the successful inhibition of NOB, AOB enrichment was low despite high ammonia concentration. The second half of this study focused on the operation of pilot scale AGS partial nitrification SBRs. The pilot system was tested with two different start-up strategies on high ammonia centrate and delivered above 80% removal efficiency. It was found that start-up from activated sludge and partial denitrification AGS was more successful and stable than start-up via UASB granular sludge combined with dehydrated AGS granules. HRT was also optimized during this time suggesting an 8hr cycle was sufficient for the maintenance of 80% ammonia removal efficiency. Denitritation was not successfully implemented in the reactors due to recirculation problems but was overall successful in the mitigation of effluent ammonia levels when treating municipal centrate at the pilot scale.
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- Graduation date
- Fall 2023
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.