What is biofiltration and its role in pollution control?

• A. Biofiltration uses microbial communities on filter media to degrade organic pollutants in air or water.
• B. Biofiltration relies solely on physical filtration without microbes.
• C. Biofiltration is chemical treatment that oxidizes pollutants.
• D. Biofiltration is wastewater disposal without treatment.

Answer: (A)

Biofiltration uses microbial communities on filter media to degrade organic pollutants in air or water. Microbes form a biofilm on the media and metabolize contaminants as the polluted stream passes through, turning pollutants into harmless end products such as carbon dioxide, water, and new microbial cells. This approach works well for odors and volatile organic compounds in air, and for biodegradable organics in water, offering a low-energy, room-temperature treatment compared with chemical or high-energy processes. Maintaining adequate moisture, oxygen, nutrients, and residence time is crucial to keep the microbes active and effective. It is less suitable for inorganic pollutants or highly toxic substances, which require different treatment methods. The other described methods—pure physical filtration without biology, or chemical oxidation, or disposal without treatment—do not utilize microbial degradation and therefore do not reflect biofiltration.