Abstract
Tetrachloroethylene (PCE) was decreased by an activated sludge acclimated with a high concentration of PCE under aerobic conditions, and 0.61 ㎎ of PCE was decreased by its cell-free filtrate. These results indicate that PCE was not adsorbed by sludge flocks or microorganisms in activated sludge and the substance (s) in the activated sludge were related to the decrease of PCE. The cell-free filtrate was not able to decrease PCE after heat or activated charcoal treatments. The substance (s) functioning PCE-decrease was supposed to be proteinous with low molecular weight since a low molecular weight cut-off fraction of 3,000 was able to decrease PCE. None of the degradation products derived from PCE were detectable by GC-FID, GC-TCD, GC-MS, or ion chromatography, however, X-ray absorption and fine structure analysis with synchrotron revealed that the C-Cl bond of PCE was cleaved, and the chloride atom existed in an ion state. These results suggest that a novel mechanism of PCE degradation was involved.
