Ma. Deshusses, TRANSIENT-BEHAVIOR OF BIOFILTERS - START-UP, CARBON BALANCES, AND INTERACTIONS BETWEEN POLLUTANTS, Journal of environmental engineering, 123(6), 1997, pp. 563-568
The work describes the aerobic biodegradation of volatile organic comp
ound (VOC) mixtures from effluent air streams in laboratory-scale comp
ost based biofilters. A rapid start-up of the system (3-5 d) was obser
ved and 82% of the carbon in the influent pollutant (methyl ethyl keto
ne) was recovered as carbon dioxide in the exhaust air after this peri
od. Biofilter performance and carbon dioxide production were also inve
stigated during and after 0.5-1-h step inputs of 2-10 g m(-3) of hexan
e, acetone, 1-propanol, and/or methyl isobutyl ketone (MIBK) during st
eady methyl ethyl ketone (MEK) treatment. Carbon dioxide patterns sugg
est that pulsed pollutants were first sorbed onto the packing material
and subsequently degraded within 2-5 h. Hexane was not sorbed, and th
us not degraded to a significant extent. Little effect was observed of
the step inputs on the overall MEK removal process, mainly because th
e reactors were operated well below MEK breakthrough loading. However,
the analysis of MEK profiles within the biofilter bed showed that sig
nificant inhibition did indeed occur. An even more important inhibitio
n was observed between 1-propanol, MIBK, and acetone, when such a mixt
ure was injected into the reactor. Practical design of biofilters shou
ld consider the possibility of reduced performances due to the presenc
e of multiple VOCs in the waste air stream.