Improved methane production from corn straw using anaerobically digested sludge pre-augmented by nanobubble water

Area of Science:

• Biotechnology
• Environmental Science
• Chemical Engineering

Background:

• Nanobubble water (NBW) improves methane production from organic waste.
• Increased reactor volume from NBW addition limits practical application.
• Pre-augmentation of anaerobic sludge is explored to overcome NBW limitations.

Purpose of the Study:

• To investigate the efficacy of NBW pre-augmented anaerobic sludge as inoculum for methane production.
• To evaluate the impact of N2-NBW and O2-NBW on substrate degradation and methane yield.
• To assess a novel approach for NBW-based anaerobic digestion without increasing reactor volume.

Main Methods:

• Anaerobically digested sludge was pre-augmented using N2-NBW and O2-NBW with corn straw as substrate.
• Electron transfer activity was monitored during pre-augmentation.
• Cellulose and hemicellulose reduction, and methane yield were measured in control and NBW-pre-augmented reactors.

Main Results:

• N2-NBW and O2-NBW pre-augmentation reduced cellulose by 33% and 38%, and hemicellulose by 35% and 35%, respectively.
• Methane yields from N2-NBW and O2-NBW pre-augmented sludge were 127 mL/g-VS and 142 mL/g-VS.
• These yields represent a 10% and 22% increase compared to the control.

Conclusions:

• Pre-augmenting anaerobic sludge with NBW significantly enhances methane yield from corn straw.
• This method provides a novel, cost-effective strategy for NBW-based anaerobic digestion without increasing reactor volume.
• NBW pre-augmented sludge is a viable inoculum for improving biogas production efficiency.