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Establishment of the Permeability Model for Soft Solid Sludge Conditioned with Flocculants
Guohong Feng1, Tiantian Bai1, He Ma1
1School of Environment & Safety, Taiyuan University of Science & Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan 030024, Shanxi, China.
ACS Omega
|November 19, 2019
Summary
Flocculants significantly impact sludge dewatering by altering microstructure and permeability. Understanding sludge permeability, influenced by flocculant type and dosage, is crucial for efficient filtration processes.
Area of Science:
- Environmental Science
- Chemical Engineering
- Materials Science
Background:
- Sludge dewatering is critical for waste management and resource recovery.
- Permeability is a key factor influencing dewatering efficiency, particularly for soft solids like sludge.
- The effectiveness of flocculants in modifying sludge properties for dewatering requires further investigation.
Purpose of the Study:
- To investigate the influence of different flocculants on sludge physicochemical properties and dewatering performance.
- To analyze the relationship between sludge microstructure, permeability, and dewatering outcomes.
- To refine the Kozeny constant for improved description of fluid flow in conditioned sludge.
Main Methods:
- Conditioning sludge with various flocculants.
- Characterizing sludge microstructure (floc morphology, specific surface area, fractal dimension).
- Measuring sludge permeability and filtration resistance under varying pressures and dosages.
- Correcting and determining the improved Kozeny constant.
Main Results:
- Flocculants alter sludge microstructure, affecting specific surface area and fractal dimension.
- Sludge permeability is significantly influenced by flocculant type and dosage, more so than filtration pressure.
- A negative correlation exists between sludge permeability and filtration pressure; a positive correlation exists with flocculant dosage.
- Permeability's role in dewatering is more pronounced with inorganic flocculants compared to organic ones.
- The improved Kozeny constant was determined based on flocculant characteristics and filtration pressure, showing a substantial decrease for conditioned sludge.
Conclusions:
- Flocculant conditioning is a highly effective strategy for enhancing sludge dewaterability by modifying permeability.
- The improved Kozeny constant provides a valuable parameter for predicting and optimizing sludge dewatering processes.
- Understanding the interplay between flocculants, sludge properties, and permeability is essential for practical dewatering applications.
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