Methane Elimination Using Biofiltration Packed With Fly Ash Ceramsite as Support Material

Area of Science:

• Environmental Science
• Biotechnology
• Microbiology

Background:

• Methane is a potent greenhouse gas contributing to global warming.
• Methane biofiltration using immobilized methane-oxidizing bacteria (MOB) offers an eco-friendly elimination strategy.
• Optimizing support materials is crucial for high methane elimination capacity (EC).

Purpose of the Study:

• To evaluate fly ash ceramsite (FAC) as a support material for immobilizing MOB.
• To compare the methane elimination performance of immobilized MOB on FAC with suspended MOB.
• To investigate the factors influencing MOB immobilization on FAC.

Main Methods:

• Inoculation of MOB consortium in biofilters with 1% methane (v/v).
• Measurement of methane elimination capacity (EC) in biofilters packed with FAC and suspended cultures.
• Quantitative PCR (qPCR) to determine pmoA gene abundance for MOB biomass estimation.
• X-ray Photoelectron Spectroscopy (XPS) and contact angle measurements to analyze FAC surface properties.

Main Results:

• Biofilters packed with FAC demonstrated the highest average methane EC (4.628 g h⁻¹ m⁻³), 33.4% higher than suspended MOB.
• FAC surface showed the highest pmoA gene abundance, indicating superior MOB immobilization.
• FAC's surface elemental composition and hydrophilicity positively correlated with MOB immobilization.

Conclusions:

• Fly ash ceramsite is an exceptional support material for immobilizing MOB in biofilters.
• Immobilization on FAC significantly enhances methane elimination efficiency.
• FAC's surface properties are key factors for effective MOB immobilization and improved methane removal.