Investigation of efficiency of cassette biofilters, designed for air cleaning from xylene

Abstract

The experimental investigations were carried out, using the biofilter BIOF-I with the system of III cleaning stages, loaded with charge, composed of zeolite granules, wood chips, barks and foam, as well as the biofilter of II cleaning stages BIOF-II, loaded with the mixture of zeolite and wood barks. When mixing the zeolite granules with wood barks for air cleaning from xylene, not only biological, but also adsorptive air treatment method is used. Applying the complex cleaning technologies, the effectiveness of equipment cleaning as well as the life cycle of charge is improved. Cultivating the associations of spontaneous microorganisms in the charge, the dependence of cleaning efficiency of biofilters on the concentration of supplied pollutant and the speed of air flow was determined. When cleaning air from xylene with the initial concentration of pollutant equal to 120±5 mg/m3, the efficiency of filters BIOF-I and BIOF-II was 94 %. The air cleaning efficiency of biofilters increases, when reducing the speed of supplied polluted air flow. In case of reducing the air flow speed from 0.3 to 0.1 m/s, the efficiency of biofilters BIOF-I and BIOF-II increases from 75 to 83 % and from 75 to 84 %, respectively.