Enhancement of the dewaterability of sludge during bioleaching mainly controlled by microbial quantity change and the...

Area of Science:

• Environmental Science
• Microbiology
• Chemical Engineering

Background:

• Sludge dewatering is crucial for efficient waste management.
• Bioleaching offers a sustainable approach to sludge treatment.
• Understanding factors influencing dewaterability is key to process optimization.

Purpose of the Study:

• To investigate and quantify the contribution rates of various factors affecting sludge dewaterability during bioleaching.
• To identify the dominant factors controlling sludge dewaterability enhancement.

Main Methods:

• Sludge bioleaching experiments were conducted.
• Factors analyzed included sludge pH, microbial quantity, and extracellular polymeric substances (EPS).
• Ridge regression analysis was employed to determine contribution rates.

Main Results:

• Sludge dewaterability was enhanced by microbial growth (Acidithiobacillus sp.), increased Fe(3+) concentration, decreased sludge pH, changes in heterotrophic microorganism quantity, and reduced EPS and bound water.
• Microbial quantity change (32.50%), bound water content (24.24%), and slime EPS content (22.37%) were identified as dominant factors.

Conclusions:

• Sludge dewaterability during bioleaching is primarily controlled by microbial quantity changes, reduction in bound water, and decrease in slime EPS.
• Optimizing these factors can significantly improve the efficiency of bioleaching-based sludge treatment.