Enhancing volatile fatty acid production from sewage sludge in batch fermentation tests

Area of Science:

• Environmental Science
• Biotechnology
• Microbiology

Background:

• Sewage sludge is a rich source of volatile fatty acids (VFAs), valuable resources for wastewater treatment.
• Optimizing sludge pre-treatment methods is essential for maximizing VFA recovery efficiency.

Purpose of the Study:

• To investigate the efficacy of four different sludge pre-treatment methods on VFA production.
• To identify the optimal pre-treatment condition for enhanced VFA recovery from sewage sludge.

Main Methods:

• Acidogenic fermentation of sewage sludge under batch reactor conditions.
• Evaluation of four pre-treatment strategies: potassium permanganate (KMnO4), pH 10, pH 2.5, and low-temperature thermal hydrolysis.
• Chemical analysis of volatile fatty acids (VFAs) and metataxonomic analysis of microbial communities.

Main Results:

• Potassium permanganate pre-treatment at 0.1 g KMnO4/g total suspended solids (TSS) yielded the highest VFA concentrations (2713 mgCOD/L and 452 mgCOD/g volatile suspended solids).
• Pre-treatment significantly influenced the prokaryotic microbial structure within the sewage sludge.
• Other pre-treatments (pH 10, pH 2.5, thermal hydrolysis) showed varying degrees of VFA production and microbial community shifts.

Conclusions:

• Potassium permanganate pre-treatment is a highly effective method for enhancing VFA recovery from sewage sludge.
• Optimized pre-treatment strategies can significantly improve resource recovery in wastewater treatment.
• Sludge pre-treatment impacts microbial community structure, which may influence fermentation efficiency.