Biological air cleaning using activated wood chips and bark charge

Abstract

The biological air treatment method is based on the biological destruction using certain cultures of microorganisms. The method is simple and can be applied in many branches of industry. The activated charge consisting of fir bark and wood in chips was used in this research. According to the research findings, the biggest reduction of pollutant concentration was recorded in the biofilter layers consisting of the fir bark charge. Having passed through two charge layers of 0.30 m thickness the concentration of acetone decreased by around 50 %. When using wood in chips the efficiency of acetone decreases. Such reduction of pollutants is predetermined by a more porous layer of the charge whose porosity reaches 60 %. A bigger porosity predetermines better moistening of the charge as well as the emergence of more favourable conditions for the development of microorganisms. The charge is distinguished by the best cleaning properties when the airflow is supplied to the device at a small velocity - 0.2 m/s because when the velocity is low the time of contact of the polluted air and the biocharge is extended. Seeking to extend the durability of the charge, it is recommended to clean air using the mixture of fir barks and wood in chips. The research has proved that when using the mixture of fir bark and wood in chips for the biological air treatment, the charge cleaning efficiency change sinsignificantly and at the same time the durability of the biocharge is extended.