Biodegradation of Methyl Ethyl Ketone and Methyl Isopropyl Ketone in a Composite Bead Biofilter

Abstract

AbstractBiodegradation of methyl ethyl ketone (MEK) and methyl isopropyl ketone (MIPK) in a composite bead biofilter was investigated. The composite bead represents a spherical PVA/peat/KNO3/GAC one. Both the microbial growth rate μ and the biochemical reaction rate coefficient kd could be affected with increasing inlet concentration. For the microbial growth process, an inhibitory effect of almost the same sensitivity for the two ketone compounds and the μ value of MEK was more pronounced than that of MIPK in the inlet concentration range of 100 to 300 ppm. The half‐saturation constant Ks values of MEK and MIPK were 21.56 and 22.96 ppm, respectively. The maximum reaction rate Vm values of MEK and MIPK were 9.06 and 7.55 g C/h kg of packed material, respectively. Zero‐order kinetics with diffusion limitation could be regarded as the most adequate biochemical reaction model. For the biochemical process, the inhibitory effect for MEK was more notable than that for MIPK in the inlet concentration range of 100 to 150 ppm whereas it was the reverse in the inlet concentration range of 150 to 300 ppm. The kd value of MEK was greater than that of MIPK in the inlet concentration range of 100 to 300 ppm. The maximum elimination capacities of MEK and MIPK were found to be 44.2 and 35.2 g C/h m3 of bed volume. MEK, in particular the compound with a lower number of carbons or no side groups in the main chain, was easier biodegraded by the microorganisms than MIPK.