Enhanced sludge dewatering using a novel synergistic iron/peroxymonosulfate-polyacrylamide method

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Materials Science

Background:

• Sludge dewatering faces challenges due to strong interactions between extracellular polymeric substances (EPS) and bound water.
• Effective sludge treatment is crucial for wastewater management and resource recovery.

Purpose of the Study:

• To develop and evaluate a novel synergistic conditioning method for enhancing sludge dewatering efficiency.
• To investigate the mechanisms underlying the improved dewatering performance.

Main Methods:

• A combined conditioning approach utilizing iron(II) (Fe2+)/peroxymonosulfate (PMS) and polyacrylamide (PAM).
• Analysis of sludge dewatering performance using specific filtration resistance (SFR) and capillary suction time (CST).
• Application of Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory and Flory-Huggins theory to understand surface properties and filtration mechanisms.

Main Results:

• The Fe2+/PMS-PAM conditioning method reduced SFR by 82.75% and CST by 80.44%.
• Fe2+/PMS pre-oxidation effectively degraded EPS and released bound water.
• PAM enhanced flocculation of sludge particles, and surface analysis showed a shift from hydrophilic to hydrophobic characteristics.

Conclusions:

• The synergistic Fe2+/PMS-PAM conditioning method significantly improves sludge dewatering by degrading EPS and optimizing flocculation.
• Thermodynamic analysis provides a deeper understanding of sludge conditioning and filtration mechanisms.
• This approach offers innovative strategies for sludge treatment and management.