Bacterial community dynamics and pollutant removal mechanisms in biofilters: A literature review

Background: The lack of understanding of how pollutant removal occurs in biofilter reactors and bacterial community dynamics makes this worthy of study. This review explores biofiltration processes, commonly used biofilter types, bacterial community dynamics, and pollutant removal mechanisms in biofilters. Methods: This review used data from previous studies published on Scopus, EBSCO, and ProQuest, categorized into parameters such as the biofiltration process, types of biofilters, bacterial community dynamics, and pollutant removal mechanisms. The data were narrated, analyzed in a table, and presented in a review. Results: In the biofilter reactor, microorganisms cover the medium, allowing pollutants to flow through gaps and contact the biofilm layer. As the biofilm thickens, adhesion weakens, leading to new colonies. Submerged-bed biofilters, trickling filters, and packed column aeration and gasification systems effectively remove nutrients from aquatic environments. Biofilter bacterial communities are categorized by filter layer depth, with fast-growing, less specialized communities in the upper layer and more specialized communities in the bottom layer. Pollutant biodegradation depends on various factors such as nutrient availability, oxygen concentration, pH, bioavailability of contaminants, and physical and chemical characteristics of the biomass. Conclusion: A biofilter reactor uses microorganisms to cover a medium, allowing pollutants to flow through gaps and contact a biofilm layer that degrades organic compounds. Submerged-bed biofilters, trickling filters, and packed column aeration systems can effectively remove pollutants. Biofilter bacterial communities are categorized by filter layer depth, with fast-growing, less specialized communities in the upper layer, and more specialized communities in the bottom layer.