Microbubble- and nanobubble-aeration for upgrading conventional activated sludge process: A review

Area of Science:

• Environmental Science
• Chemical Engineering
• Water Treatment Technology

Background:

• Activated sludge process (ASP) is a cornerstone of wastewater treatment.
• Aeration efficiency is critical for effective ASP operation.
• Conventional macro-bubble aeration has limitations in efficiency.

Purpose of the Study:

• To systematically review microbubble (MB) and nanobubble (NB) aeration for ASP.
• To elucidate the properties and generation of MBs and NBs.
• To understand the mechanistic improvements in gas-liquid mass transfer.

Main Methods:

• Literature review of MB and NB aeration technologies.
• Analysis of unique properties and generation methods of MBs and NBs.
• Examination of mechanistic insights into gas-liquid mass transfer enhancement.

Main Results:

• MB and NB aeration offer superior gas-liquid mass transfer compared to macro-bubbles.
• These advanced aeration methods can significantly upgrade ASP efficiency.
• Specific applications and resultant effects in ASP are highlighted.

Conclusions:

• MB and NB aeration present a promising upgrade for activated sludge processes.
• Further research is needed to fully explore their potential in wastewater treatment.
• Optimizing MB and NB aeration can lead to more efficient and sustainable wastewater treatment.