Enhancing phosphorus recovery from sewage sludge using anaerobic-based processes: Current status and perspectives

Area of Science:

• Environmental Science
• Biotechnology
• Chemical Engineering

Background:

• Phosphorus (P) recovery from sewage sludge is crucial for sustainability.
• Anaerobic-based processes are cost-effective and eco-friendly for P recovery.
• Current P release efficiencies in these processes are often insufficient.

Purpose of the Study:

• To systematically review P release mechanisms from sewage sludge using anaerobic processes.
• To analyze obstacles hindering P release and discuss advancements in enhancing it.
• To propose perspectives for practical P recovery applications.

Main Methods:

• Literature review and systematic summarization of anaerobic-based P recovery processes.
• Analysis of different phosphorus species and their release pathways.
• Discussion of limiting factors and enhancement strategies.

Main Results:

• Different P species exhibit varying release behaviors under distinct anaerobic conditions.
• Extracellular polymeric substances and excess metal ions are identified as key inhibitors.
• Acid fermentation and anaerobic fermentation with sulfate reduction show high P release efficiencies (up to 64% and 63%, respectively).

Conclusions:

• Anaerobic processes can effectively recover phosphorus from sewage sludge.
• Addressing limitations like extracellular polymeric substances and metal ions is key to improving efficiency.
• Specific anaerobic fermentation strategies show significant promise for industrial P recovery.