Abstract

Air pollution has become a major concern because it is inevitably connected with the rapid development of both industrial and residential areas. Volatile organic compounds (VOCs) are emitted from various anthropogenic sources e.g. transportation, factories or landfills as well as recycling factories. It is problematic not only because of the direct impact on humans and environment but also from economy viewpoint as it increases costs of environmental remediation of contaminated eco- systems. Mitigation of VOCs emissions into air is achieved through prevention or purification of gaseous streams. Among separation and purification technologies used for removal of VOCs from gas phase, techniques based on biological processes are under development for over 40 years and are gaining more attention due to economic feasibility, eco-friendly character and high removal efficiency of pollutants elimination. They are based on the capability of microorganisms (fungi and bacteria) to utilize harmful VOCs as a carbon source for their metabolic processes in the absence of typical nutrients e.g. carbohydrates. During biofiltration process, a polluted air is fed into a biofilter column with a packed bed inhabited by various microorganisms. While passing through the column’s bed, VOCs diffuse from a gas phase to a biofilm formed by fungi and/or bacteria species growing on the packing elements where and undergo biodegradation. As a result, a purified gas stream leaves a biofilter and an increase in the biomass growth is observed (Fig. 1). Beside biomass, carbon dioxide, water as well as sulphates and nitrates are produced. They can be removed from a column with gas stream or dissolved in the liquid phase. The most popular apparatus for biofiltration include conventional biofilters, biotrickling filters and bioscrubbers . In this work, mechanisms of biofiltration and biotrickling filtration are discussed. Experimental results of investigations regarding the biofilm composition, selection of preferential microbial species as well as removal efficiency of selected VOCs in a peat-perlite biotrickling filter are presented.

Authors (4)