Investigation of the effect of specific operational parameters on a process of chloroform cometabolic biodegradation by butane-grown biomasses

An aerobic cometabolic CF degradation process by butane-grown biomasses was studied by means of slurry microcosm tests. The lag-phase for the onset of butane utilization by the indigenous biomass of the studied sandy soil was lower than 2 weeks in all the experimental conditions tested. The lag-time for the onset of CF depletion was strongly affected by temperature, with no CF degradation after several weeks in the tests conducted at 15°C. Bioaugmentation treatments performed with 2 types of microbial inocula led, even at the smallest dose tested (0.15 grams of dry cell / m^3 of aq. phase), to a marked decrease of the butane lag-time. Both the initial CF degradation rate and the amount of CF depleted in the absence of butane proved to depend on the type of inoculum utilized, rather than on its dose. The minimum butane/CF molar ratio required to carry out a sustainable CF degradation process proved to be comprised between 1.6 and 14.