Tubular biofilter treatment of isobutanol emissions under various organic loading rates

Isobutanol in waste gas streams was treated by a tubular biofilter (TBF) which continuously operated for 364 days under various organic loading rate (OLR) from 11 g.m(-3) .h(-1) to 66 g.m(-3) .h(-1). Results show that within 60 days, the TBF successfully started up even after changing the OLR from 31.3 to 15.6 g.m(-3) h(-1). The average removal efficiencies (REs) were totally higher than 90% when OLRs ranged from 12.14 to 66.45 g.m(-3) h(-1). Two distinct performance deterioration periods were observed at days 186-253 and days 280-334, both of which recovered without additional measurement. During these periods, the larvae and adult moth flies, been identified as Psychodinae infested the TBF, greatly affected the TBF performance. When the number of adult Psychodinae decreased, TBF performance recovered. The elimination capacity (EC) was 60.42 g.m(-3) .h(-1) at the inlet OLR of 66.45 g.m(-3) .h(-1), with the critical EC being around 50 g.m(-3) .h(-1). Even under a low gas empty bed residence time of 15 s, the preferable REs and ECs under middle or low OLRs were still obtained by the TBF.