Biological air treatment systems
Biological air treatment systems rely on microbial activity to degrade specific gaseous pollutants under controlled operating conditions.
Their effectiveness, however, depends strictly on the stability of the process environment, rather than on the biological medium itself.
Biofilters and biotrickling systems are not universal solutions. They are process units, whose performance is defined by pollutant characteristics, operating continuity and biological balance.
What Is Biological Air Treatment?
Biological air treatment remove gaseous contaminants by transferring pollutants from the air phase into a biologically active medium where microorganisms degrade them.
This approach is particularly effective for odorous compounds and biodegradable pollutants, including hydrogen sulfide, ammonia and various volatile organic compounds.
Unlike purely physical or chemical treatment technologies, biological systems rely on microbial activity and environmental stability, which means that process conditions strongly influence long-term performance.
Operating Principle of Biofilters, biotrickling and bioscrubbers
In biological air treatment systems, contaminated air is brought into contact with a moist biologically active surface where pollutants dissolve into a thin liquid layer.
Microorganisms living in this biofilm metabolise the absorbed compounds and convert them into stable end products such as carbon dioxide, water and biomass.
Because pollutant removal depends on both mass transfer and microbial kinetics, reactor design and operating conditions play a critical role.
Biotrickling & Bioscrubbers reference standards
Biological Air Treatment Reactor Configurations
Industrial biofiltration is implemented using different reactor architectures depending on pollutant characteristics and operating conditions.
The most widely used configurations include biofilters, biotrickling filters and bioscrubbers, each based on different mechanisms for transferring pollutants from the gas phase to the biologically active phase.
Selecting the correct reactor configuration depends on pollutant characteristics, inlet gas conditions and process stability requirements.
Biofilters
Biofilters treat contaminated air by passing it through a biologically active packed bed where microorganisms degrade absorbed pollutants.
Biotrickling Filters
Biotrickling filters use an irrigated packed column where a recirculating liquid phase supports microbial growth and pollutant biodegradation.
Bioscrubbers
Bioscrubbers combine gas absorption and biological degradation in two stages.
Pollutants are first absorbed in a scrubbing liquid and then biologically degraded in a separate bioreactor.
Key Design Factors in Biofiltration
Successful biofiltration requires maintaining stable operating conditions that allow microbial populations to remain active and efficient.
Important design factors include:
Proper system design ensures long-term performance and prevents biological process instability.