코르크와 BAC(Biological Activated Carbon) 충진재를 이용한 개스상태 BTEX의 생물학적인 제거특성 비교 연구

Abstract

Biofilters equipped with packing media, cork or biological activated carbon (BAC), were successfully operated for 126 days. Target gases were BTEX, mixture of benzene, toluene, ethyl benzene and xylene. The biofilter having cork in the packing column was performed better than the one with BAC in general. During the initial stage (first two weeks) so called adaptation period for biological activation or acclimation, the BAC biofilter had higher removal performance than the cork biofilter mostly owing to much higher adsorption capacity of activated carbon, i.e. the longer breakthrough point for BAC. After that, however, the cork biofilter was always better; even in phase II which has three times higher inlet gas concentration, the removal efficiency on cork biofilter was over 90% meanwhile that on BAC biofilter ranged between 60-80%. The maximum elimination capacities were 86 g/m3/h for the cork and 67 g/m3/h for the BAC around 94 g/m3/h of inlet load. Production of CO2 gas was highly well correlated with biomass in the media during the entire operation period except the phase III, for a while of which no substrates were provided to the microbial consortia thus resulting in less amount of CO2 generated from them (biomass) than expected. We also figured out how the concentrations of gases would change over height of the column; from the inlet up to 1/3 of the whole length of the packed columns, 79% of the inlet concentration of BTEX gas in the cork biofilter, which has shown higher concentration gradient was removed. The degradation rates for both filters dropped rapidly afterwards.