Biofiltration of a methanol containing air stream in a dry tubular biofilm reactor using ceramic rings as carrier

Abstract

A 13.4 L dry tubular biofilm reactor (DTB), with ceramics rings as carrier, was used to treat a polluted air stream using methanol as a model pollutant. The design of this reactor was based on the creation of a mist by contacting the waste gas and a liquid nutrient solution inside an atomizing nozzle. The liquid was supplied intermittently (16 s every 3 min) in order to minimize water addition (91% of reactor operational time corresponded to ''dry'' conditions). The reactor was operated at empty bed residence times (EBRT) of 42 s and volumetric loading rates of 1.5-3.0 kg/m 3 /d. Biofilm growth was observed first on the walls of the reactor, and subsequently growth developed on the surface of the rings. Methanol was completely removed from the gas phase at low loading rates and the removal efficiency was around 83-93% at a loading of 3.0 kg/m 3 /d. Organic carbon mass balances showed that, in the presence of the carrier, up to 73% methanol was biodegraded; nondegraded methanol and other metabolites constituted the remaining fraction in the liquid and gas effluent.

Biofiltration of high concentrations of methanol vapors: removal performance, carbon balance and microbial and fly populations

“…across the filter bed), with various types of packing materials, operating conditions and microbial populations ( Table 1). [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Nevertheless, little is known about biofiltration limits, particularly regarding steady state operation at the maximum system capacity under high concentrations of methanol. As can be seen in Table 1, most studies have focused on the treatment of inlet methanol concentrations (C in ) below 5 g m −3 , while only three experiments have reported results above 10 g m −3 .…”

“…Biological oxidation of methanol vapors has been successfully applied in biofilters or biotrickling filters (similar to the precedents, but with continuous recirculation of a mineral medium solution across the filter bed), with various types of packing materials, operating conditions and microbial populations (Table ) . Nevertheless, little is known about biofiltration limits, particularly regarding steady state operation at the maximum system capacity under high concentrations of methanol.…”