Photocatalytic membrane combined with biodegradation for toluene oxidation

Area of Science:

• Environmental Science
• Chemical Engineering
• Biotechnology

Background:

• Volatile organic compounds (VOCs) pose environmental and health risks.
• Existing VOC treatment methods can be inefficient or costly.
• Photocatalytic membrane reactors combined with biodegradation show promise for VOC degradation.

Purpose of the Study:

• To evaluate the efficacy of a coupled photocatalysis and biodegradation reactor for toluene removal.
• To investigate the long-term performance and microbial community dynamics in the reactor.
• To assess the potential of this hybrid system as a sustainable VOC treatment technology.

Main Methods:

• Continuous operation of a hybrid photocatalytic membrane biofilm reactor for 500 days.
• Treatment of simulated waste gas containing toluene.
• Analysis of toluene removal efficiency and elimination capacity.
• Microbial community analysis using 16S rDNA and metagenomic sequencing to identify dominant genera and functional genes.

Main Results:

• Achieved 99% toluene removal efficiency with an elimination capacity of 550 µg·m⁻³·h⁻¹.
• Observed an improvement in toluene removal from 11% to 20% due to the coupled system.
• Identified key microbial genera (e.g., Lysinibacillus, Hydrogenophaga, Pseudomonas) and functional genes involved in toluene metabolism.
• Demonstrated that photocatalysis generates biodegradable intermediates, enhancing microbial degradation.

Conclusions:

• The hybrid photocatalytic membrane biofilm reactor is highly effective for toluene degradation.
• The synergistic action of photocatalysis and biodegradation enhances overall VOC removal efficiency.
• This novel reactor design presents a cost-effective and robust solution for treating VOCs in waste gas.