Long-term MIBK removal in a tubular biofilter: Effects of organic loading rates and gas empty bed residence times

A novel gas biofilter, namely the tubular biofilter (TBF) was developed and successfully used for toluene removal from waste gas streams. To furtherly explore its performance for methyl isobutyl ketone (MIBK) removal, the TBF was continuously operated for over 284 days under various organic loading rates (OLRs) (ranging from 20 to 340 g m−3 h−1) and gas empty residence times (EBRTs) (ranging from 15 to 5 s) in this paper. The results show that the TBF could achieve a high MIBK removal efficiency (RE) at a short gas EBRT of 5 s. The mean maximum REs of MIBK were 98.67%, 88.95%, 77.93%, 71.74%, and 55.92% under the OLRs of 19.89, 39.33, 78.96, 160.17, 338.02 g m−3 h−1, respectively. The maximum elimination capacity for MIBK was as high as 200 g m−3 h−1, while the critical load was about 20 - 30 g m−3 h−1. Based on the Michaelis-Menten kinetic model, the biokinetic constants Ks was found to be 8.56 g m−3 and rmax was 0.14 g m−3 h−1. The biomass clogging appeared at the EC of over 80 g m−3 h−1. The TBF showed a high efficient performance for MIBK removal due to the enhancement of highly porous polyurethane sponge and new tubular configurations.