Enhancing biological phosphorus removal with glycerol.

Area of Science:

• Environmental Science
• Environmental Engineering
• Biotechnology

Background:

• Enhanced biological phosphorus removal (EBPR) processes are vital for nutrient management in wastewater treatment.
• Acetate is a common external carbon source for EBPR, but its availability can be limited.
• Glycerol, a byproduct of biodiesel production, is a potential alternative carbon source.

Purpose of the Study:

• To investigate the effectiveness of glycerol as an external carbon source for EBPR.
• To determine the optimal method for utilizing glycerol in EBPR systems.
• To enhance phosphorus removal efficiency in wastewater treatment.

Main Methods:

• Operated an enhanced biological phosphorus removal (EBPR) reactor with acetate as the carbon source.
• Substituted acetate with glycerol in the feed to assess EBPR performance.
• Fermented waste activated sludge (WAS) with glycerol in an off-line fermenter.
• Supplied the EBPR system with VFA-enriched supernatant from the WAS fermenter.

Main Results:

• EBPR operated successfully with acetate.
• EBPR process failed when glycerol was directly substituted for acetate.
• Fermentation of WAS with glycerol produced significant volatile fatty acids (VFA).
• Supplying VFA-enriched supernatant to the EBPR system enhanced phosphorus removal.

Conclusions:

• Direct addition of glycerol to EBPR is ineffective for phosphorus removal.
• Pre-fermentation of glycerol with waste activated sludge is essential for VFA production.
• VFA-enriched supernatant from glycerol fermentation effectively enhances EBPR.
• Fermenting glycerol with WAS is the recommended approach for using glycerol as a carbon source in EBPR.