Performance of low pH biofilters treating a paint solvent mixture: continuous and intermittent loading

Area of Science:

• Environmental biotechnology
• Microbial degradation of pollutants
• Air pollution control

Background:

• Volatile organic compounds (VOCs) from paint manufacturing pose environmental challenges.
• Biofiltration is a promising technology for treating VOC emissions.
• Acclimation of microbial cultures to low pH is crucial for effective biofilter operation.

Purpose of the Study:

• To evaluate the efficacy of biofiltration using compost-derived microbial cultures for treating paint solvent mixtures.
• To compare the performance of continuous versus intermittent loading conditions in biofilters.
• To investigate the microbial community structure and its role in VOC removal.

Main Methods:

• Two biofilters were inoculated with acidic-condition-grown compost culture.
• A five-component VOC mixture simulating paint solvent emissions was used.
• Continuous and intermittent loading strategies were applied over 63 days.
• Scanning electron microscopy (SEM) was used to analyze microbial populations.

Main Results:

• Both biofilters achieved over 90% removal efficiency for VOCs.
• Continuous loading resulted in faster stabilization (3 weeks) compared to intermittent loading (6 weeks).
• Ketones were degraded faster than aromatic compounds, with some instability in aromatic removal.
• Fungi were identified as the dominant microorganisms in the biofilters.

Conclusions:

• Undefined mixed microbial cultures acclimated at low pH can effectively treat paint solvent VOCs in biofilters.
• Biofiltration is a viable method for managing air emissions from paint manufacturing.
• Fungal dominance suggests their significant role in the degradation of these VOCs.