Continuous flow aerobic granular sludge: recent developments and applications
Aerobic granular sludge (AGS) in continuous-flow reactors (CFRs) has attracted significant interest, with notable progress in research and application over the past two decades. Cumulative studies have shown that AGS-CFRs exhibit comparable morphology, settleability, and pollutant removal efficiency...
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| Format: | Article |
| Language: | English |
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IWA Publishing
2024-03-01
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| Series: | Water Science and Technology |
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| Online Access: | http://wst.iwaponline.com/content/89/5/1155 |
| _version_ | 1797200750112145408 |
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| author | Cheng Yu Kaijun Wang |
| author_facet | Cheng Yu Kaijun Wang |
| author_sort | Cheng Yu |
| collection | DOAJ |
| description | Aerobic granular sludge (AGS) in continuous-flow reactors (CFRs) has attracted significant interest, with notable progress in research and application over the past two decades. Cumulative studies have shown that AGS-CFRs exhibit comparable morphology, settleability, and pollutant removal efficiency to AGS cultivated in sequencing batch reactors, despite their smaller particle sizes. Shear force and selection pressure are the primary drivers of granulation. While not mandatory for granulation, feast/famine conditions play a crucial role in ensuring long-term stability and nutrient removal. Additionally, bioaugmentation can facilitate the granulation process. Furthermore, this paper comprehensively assesses the application of AGS-CFRs in full-scale wastewater treatment plants (WWTPs). Currently, AGS-CFRs have been implemented in nine WWTPs, encompassing two distinct processes. Hydrocyclone-based densified activated sludge significantly enhances sludge density, settleability, and biological phosphorus removal efficiency, thus increasing treatment capacity. The microaerobic–aerobic configuration with internal separators can induce granulation, ensuring long-term stability, eliminating the need for external clarifiers, and reducing land and energy requirements. This review demonstrates the high potential of AGS-CFRs for intensifying existing WWTPs with minimal retrofitting needs. However, further research is required in granulation mechanisms, long-term stability, and nutrient removal to promote the widespread adoption of AGS.
HIGHLIGHTS
Over 100 papers on AGS in CFRs were systematically reviewed.;
Full-scale applications of conventional AGS in CFRs were assessed.;
Long-term stability, particularly in the cold season, was the primary challenge.;
Further research on granulation and nutrient removal mechanisms is required.; |
| first_indexed | 2024-04-24T07:36:36Z |
| format | Article |
| id | doaj.art-b8a9635964784165b372ab78c1cdaf39 |
| institution | Directory Open Access Journal |
| issn | 0273-1223 1996-9732 |
| language | English |
| last_indexed | 2024-04-24T07:36:36Z |
| publishDate | 2024-03-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | Water Science and Technology |
| spelling | doaj.art-b8a9635964784165b372ab78c1cdaf392024-04-20T05:49:52ZengIWA PublishingWater Science and Technology0273-12231996-97322024-03-018951155117810.2166/wst.2024.055055Continuous flow aerobic granular sludge: recent developments and applicationsCheng Yu0Kaijun Wang1 State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China Aerobic granular sludge (AGS) in continuous-flow reactors (CFRs) has attracted significant interest, with notable progress in research and application over the past two decades. Cumulative studies have shown that AGS-CFRs exhibit comparable morphology, settleability, and pollutant removal efficiency to AGS cultivated in sequencing batch reactors, despite their smaller particle sizes. Shear force and selection pressure are the primary drivers of granulation. While not mandatory for granulation, feast/famine conditions play a crucial role in ensuring long-term stability and nutrient removal. Additionally, bioaugmentation can facilitate the granulation process. Furthermore, this paper comprehensively assesses the application of AGS-CFRs in full-scale wastewater treatment plants (WWTPs). Currently, AGS-CFRs have been implemented in nine WWTPs, encompassing two distinct processes. Hydrocyclone-based densified activated sludge significantly enhances sludge density, settleability, and biological phosphorus removal efficiency, thus increasing treatment capacity. The microaerobic–aerobic configuration with internal separators can induce granulation, ensuring long-term stability, eliminating the need for external clarifiers, and reducing land and energy requirements. This review demonstrates the high potential of AGS-CFRs for intensifying existing WWTPs with minimal retrofitting needs. However, further research is required in granulation mechanisms, long-term stability, and nutrient removal to promote the widespread adoption of AGS. HIGHLIGHTS Over 100 papers on AGS in CFRs were systematically reviewed.; Full-scale applications of conventional AGS in CFRs were assessed.; Long-term stability, particularly in the cold season, was the primary challenge.; Further research on granulation and nutrient removal mechanisms is required.;http://wst.iwaponline.com/content/89/5/1155aerobic granular sludgecontinuous-flow reactorsfull-scale applicationlong-term stability |
| spellingShingle | Cheng Yu Kaijun Wang Continuous flow aerobic granular sludge: recent developments and applications Water Science and Technology aerobic granular sludge continuous-flow reactors full-scale application long-term stability |
| title | Continuous flow aerobic granular sludge: recent developments and applications |
| title_full | Continuous flow aerobic granular sludge: recent developments and applications |
| title_fullStr | Continuous flow aerobic granular sludge: recent developments and applications |
| title_full_unstemmed | Continuous flow aerobic granular sludge: recent developments and applications |
| title_short | Continuous flow aerobic granular sludge: recent developments and applications |
| title_sort | continuous flow aerobic granular sludge recent developments and applications |
| topic | aerobic granular sludge continuous-flow reactors full-scale application long-term stability |
| url | http://wst.iwaponline.com/content/89/5/1155 |
| work_keys_str_mv | AT chengyu continuousflowaerobicgranularsludgerecentdevelopmentsandapplications AT kaijunwang continuousflowaerobicgranularsludgerecentdevelopmentsandapplications |