For economic and safety reasons, biofiltration is now recognized as one of the most advantageous treatment technologies available to control odors, volatile organic compounds (VOCs), and toxic air emissions from diverse municipal and industrial sources, provided the volatile compound does not need to be recovered and when the pollutant concentration does not exceed 5–10 g/m
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. It is considered a clean technology with minimal energy requirements and low waste production.
This article reviews the history and current state of the biofiltration technology, summarizes its principles, design, and operation, and discusses the applicability of biofiltration systems for a wide variety of specific emission sources. Moreover, an overview of the key factors influencing biofilter design, operation, and performance is provided.
A comparison with other biological systems outlines that conventional biofilters have the easiest mode of operation combined with quite a wide application range and relatively low capital and operating costs.
A wide picture of the biofilter applications either at pilot‐scale or full‐scale with related pollutants that can be removed is given. The results reported show that, under proper conditions, biofilters can offer high removal efficiencies for a wide range of common air pollutants.
The principal groups of microorganisms involved in biofilters as well as their respective main metabolic pathways are also presented and discussed.
Economic analysis made on different bases demonstrates that biofiltration is by far the most convenient process if applied to high flow rates of air emissions containing relatively low concentrations of easily biodegradable compounds.
Finally, current and potential future developments of the biofiltration technology are also addressed.