Dl. Freedman et Sd. Herz, USE OF ETHYLENE AND ETHANE AS PRIMARY SUBSTRATES FOR AEROBIC COMETABOLISM OF VINYL-CHLORIDE, Water environment research, 68(3), 1996, pp. 320-328
A significant problem encountered with anaerobic reductive dechlorinat
ion of polychlorinated ethylenes during groundwater remediation is acc
umulation of vinyl chloride (VC). Even when reduction of VC proceeds t
o ethylene and/or ethane, low levels of VC may persist. The purpose of
this study was to examine use of ethylene and ethane as primary subst
rates for aerobic cometabolism of VC. Both ethylene- and ethane-grown
enrichment cultures (developed with activated sludge inoculum) readily
consumed VC. The ethylene culture exhibited an initial preference for
VC over ethylene but then switched after several weeks. This culture
was unable to use ethane or VC as sole substrates. Although VC inhibit
ed ethylene use, growth on ethylene still occurred in the presence of
VC. The ethane-grown culture was able to use both VC and ethylene as s
ole substrates. When all three compounds were present, ethylene was co
nsumed first, followed by VC and ethane. Thus, the presence of ethylen
e and/or ethane with VC may eliminate the need to add a primary substr
ate (for example, methane, toluene, or phenol) to sustain cometabolism
of VC below the regulatory limit.