Short communication TREATMENT OF BENZENE VAPORS FROM CONTAMINATED AIR STREAM IN A LABORATORY-SCALE COMPOST

Biofiltration of process waste–gas streams using microorganisms attached to porous support matrix, at low concentrations and high gas flow rates, has gained importance as a versatile treatment technology ever since the Clean Air Act Amendments (1990), by the US – EPA came into existence. In this study, we evaluated the potential of a laboratory–scale biofilter, inoculated with mixed culture, to remove gas–phase benzene from a synthetic waste gas stream. Experiments were conducted in three different phases, after the acclimatization step, corresponding to empty bed residence times (EBRT) varying between 0.81–2.45 min and benzene concentrations up to 1.7 g/m3. At high concentrations, significant reduction in removal efficiency was observed, which may be due to insufficient biomass in the filter bed to utilize the substrate, or due to substrate inhibition at high concentrations. Removal efficiencies higher than 90 % were achieved for inlet benzene loading rates lesser than 40 g/m3.hr. Key words: compost biofilter; benzene; performance; removal efficiency; elimination capacity TRETMAN NA BENZENSKI PAREI OD ZAGADENA VOZDU[NA STRUJA SO LABAROTORISKI KOMPOZITEN BIOFILTE