Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge
The advanced anaerobic digestion process enhances sludge resource utilization. However, thermal hydrolysis pretreatment of anaerobically digested sludge reduces dewatering efficiency due to excessive organic matter decomposition. This necessitates significant time and effort for sludge conditioning...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-02-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/16/5/695 |
| _version_ | 1797263823135047680 |
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| author | Xiuqin Cao Ran Yu Xin Wang |
| author_facet | Xiuqin Cao Ran Yu Xin Wang |
| author_sort | Xiuqin Cao |
| collection | DOAJ |
| description | The advanced anaerobic digestion process enhances sludge resource utilization. However, thermal hydrolysis pretreatment of anaerobically digested sludge reduces dewatering efficiency due to excessive organic matter decomposition. This necessitates significant time and effort for sludge conditioning in wastewater treatment plants. Using conditioning agents can achieve high dewatering efficiency. This study investigates how the order of adding coagulants and flocculants impacts the dewatering performance of digested sludge. The results indicate that, compared to the flocculation–coagulation process with the same dosage, the coagulation–flocculation process leads to a 15–20% increase in the average particle size of digested sludge. The content of polysaccharides and proteins in S-EPS decreases by 28.8–30.8% and 10.1–11.3%, respectively. The filter cake solids content increases by 8.5%, and there is an increase in surface water channels within the flocs. This is because initially adding coagulants efficiently adsorbs small particles, forming larger aggregates that settle effectively. This promotes the breakdown of extracellular polymeric substances, releasing more bound water. Adding flocculants later bridges the aggregates, further enhancing settling and filtration performance, thereby improving sludge dewatering efficiency. These research findings contribute to a better understanding of the mechanisms of coagulant and flocculant co-conditioning for digested sludge and provide recommendations for optimizing sludge conditioning steps. |
| first_indexed | 2024-04-25T00:19:07Z |
| format | Article |
| id | doaj.art-89b935d22782407cb7543ce3b5727d66 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-04-25T00:19:07Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
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| spelling | doaj.art-89b935d22782407cb7543ce3b5727d662024-03-12T16:57:42ZengMDPI AGWater2073-44412024-02-0116569510.3390/w16050695Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested SludgeXiuqin Cao0Ran Yu1Xin Wang2School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, 1# Zhanlanguan Rd., Xicheng District, Beijing 100044, ChinaSchool of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, 1# Zhanlanguan Rd., Xicheng District, Beijing 100044, ChinaSchool of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, 1# Zhanlanguan Rd., Xicheng District, Beijing 100044, ChinaThe advanced anaerobic digestion process enhances sludge resource utilization. However, thermal hydrolysis pretreatment of anaerobically digested sludge reduces dewatering efficiency due to excessive organic matter decomposition. This necessitates significant time and effort for sludge conditioning in wastewater treatment plants. Using conditioning agents can achieve high dewatering efficiency. This study investigates how the order of adding coagulants and flocculants impacts the dewatering performance of digested sludge. The results indicate that, compared to the flocculation–coagulation process with the same dosage, the coagulation–flocculation process leads to a 15–20% increase in the average particle size of digested sludge. The content of polysaccharides and proteins in S-EPS decreases by 28.8–30.8% and 10.1–11.3%, respectively. The filter cake solids content increases by 8.5%, and there is an increase in surface water channels within the flocs. This is because initially adding coagulants efficiently adsorbs small particles, forming larger aggregates that settle effectively. This promotes the breakdown of extracellular polymeric substances, releasing more bound water. Adding flocculants later bridges the aggregates, further enhancing settling and filtration performance, thereby improving sludge dewatering efficiency. These research findings contribute to a better understanding of the mechanisms of coagulant and flocculant co-conditioning for digested sludge and provide recommendations for optimizing sludge conditioning steps.https://www.mdpi.com/2073-4441/16/5/695sludge dewateringadvanced anaerobic digestionaddition sequencecoagulationflocculation |
| spellingShingle | Xiuqin Cao Ran Yu Xin Wang Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge Water sludge dewatering advanced anaerobic digestion addition sequence coagulation flocculation |
| title | Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge |
| title_full | Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge |
| title_fullStr | Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge |
| title_full_unstemmed | Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge |
| title_short | Impact of Conditioning Agent Addition Sequence on Dewatering Performance of Advanced Anaerobic Digested Sludge |
| title_sort | impact of conditioning agent addition sequence on dewatering performance of advanced anaerobic digested sludge |
| topic | sludge dewatering advanced anaerobic digestion addition sequence coagulation flocculation |
| url | https://www.mdpi.com/2073-4441/16/5/695 |
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