A Review of the Role of Extracellular Polymeric Substances (EPS) in Wastewater Treatment Systems
Abstract
:1. Introduction
2. Fundamentals of EPS
2.1. EPS Structure and Distribution
2.2. Methods of Extracting EPS
3. Biological Characteristics of EPS
3.1. Stability
3.2. Adhesion Ability
3.3. Biodegradability
4. Contaminant Removal
4.1. Organic Matter Removal
4.2. Nitrogen and Phosphorous Removal
4.3. Metal Ion Removal
5. Effect of EPS on Sludge Properties
5.1. Effects of EPS on Flocculation Ability
5.2. Effects of EPS on Settling Ability
5.3. Effects of EPS on Dewatering Ability
6. Findings
7. Conclusions
8. Recommendations
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Methods | Mechanism | Features | Disadvantages | References | |
---|---|---|---|---|---|
Physical | Centrifugation | EPS are separated from cell surface and then dissolve to solution under the centrifugal force. |
|
| [8,11,22,23,24] |
Heating | EPS dissolution will be accelerated by enhancing molecular movement with heating. |
|
| [11,22,25,26] | |
Sonication | EPS of biofilm matrix are extracted under different impulsive pressures created by sonication. |
|
| [11,22,27,28,29] | |
Sonication/centrifugation | EPS will dissolve into solution under the impulsive pressure created by the sonication and centrifugal force. |
|
| [22,30] | |
Chemical | Acidic treatment | EPS are fallen away from the cell surface, as the interaction between EPS and cells is disrupted by the repulsive force. |
|
| [8,11,22] |
Alkaline treatment | Alkaline treatment with NaOH addition causes the groups to be ionized, resulting in a strong repulsion between EPS and cells. |
|
| [8,11,22] | |
CER | CER removes the divalent cations resulting in EPS falling apart. |
|
| [8,11,22,31] | |
EDTA | EPS matrix will fall apart, because divalent cations for the cross-linking of charged compounds are removed using EDTA. |
|
| [8,11,22,32] | |
Enzymatic extraction | The carbohydrate and protein-hydrolyzing enzymes are used to disrupt the structure of sludge and dissolve EPS. |
|
| [11,22,33] | |
HCHO/NaOH | HCHO reduces the cell lysis caused by NaOH addition. |
|
| [11,29,34] |
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Huang, L.; Jin, Y.; Zhou, D.; Liu, L.; Huang, S.; Zhao, Y.; Chen, Y. A Review of the Role of Extracellular Polymeric Substances (EPS) in Wastewater Treatment Systems. Int. J. Environ. Res. Public Health 2022, 19, 12191. https://doi.org/10.3390/ijerph191912191
Huang L, Jin Y, Zhou D, Liu L, Huang S, Zhao Y, Chen Y. A Review of the Role of Extracellular Polymeric Substances (EPS) in Wastewater Treatment Systems. International Journal of Environmental Research and Public Health. 2022; 19(19):12191. https://doi.org/10.3390/ijerph191912191
Chicago/Turabian StyleHuang, Lei, Yinie Jin, Danheng Zhou, Linxin Liu, Shikun Huang, Yaqi Zhao, and Yucheng Chen. 2022. "A Review of the Role of Extracellular Polymeric Substances (EPS) in Wastewater Treatment Systems" International Journal of Environmental Research and Public Health 19, no. 19: 12191. https://doi.org/10.3390/ijerph191912191