Use of Compact Trickle Bed Bioreactor For The Purification of Air From A Voc’s Mixture – Preliminary Research

The study presents the preliminary results of research with the aim to test a Compact Trickle-Bed Bioreactor (CTBB) to the biopurification of air from VOC’s mixtures (ethyl alcohol, dimethyl sulphide, styrene). The experiments were performed using a 45 dm³ semi-industrial scale bioreactor in which gas and liquid phases flowed co-currently in downward direction through a bed made up of polyethylene rings. The bioreactor was inoculated with a co-culture of microorganisms including bacterial strains found in the wastewater and adopted to chosen pollutants. The gas-flowrate was 4.0 m³/h and VOC concentration in the gas phase was changed from 40 to 255 ppm. In the whole period of research the efficiency of pollutant removal was in the range 92-99%. The lowest result of efficiency was achieved in the 2^nd day of research as a response of the highest concentration of VOC. Possible consequences of a violent pollutant overload and the time required for regenerating the microorganisms and returning to the stable process conditions were also investigated. An increase of VOC concentration to 220-255 ppm did not significantly influence the deterioration of process efficiency. After the period of adaptation of microorganism to the process condition and immobilization of microflora on the packing material, the experimental set-up has been working reliably for 21 days.