Bioremediation of coal contaminated soil under sulfate-reducing condition.
The objective of this study was to investigate the biodegradation of coal-derived hydrocarbons, especially high molecular weight (HMW) components, under anaerobic conditions. For this purpose biodegradation experiments were performed, using specifically designed soil column bioreactors. For the experiment, coal-contaminated soil was prepared, which contains high molecular weight hydrocarbons at high concentration (approx. 55.5 mgC g-drysoil(-1)). The experiment was carried out in two different conditions: sulfate reducing (SR) condition (SO4(2-) = 10 mmol l(-1) in the liquid medium) and control condition (SO4(2-)<0.5 mmol l(-1)). Although no degradation was observed under the control condition, the resin fraction decreased to half (from 6,541 to 3,386 mgC g-soil(-1)) under SR condition, with the concomitant increase of two PAHs (phenanthrene and fluoranthene, 9 and 2.5 times, respectively). From these results, we could conclude that high molecular hydrocarbons were biodegradable and transformed to low molecular weight PAHs under the sulfate-reducing condition. Since these PAHs are known to be biologically degraded under aerobic condition, a serial combination of anaerobic (sulfate reducing) and then aerobic bioremediations could be effective and useful for the soil pollution by petroleum and/or coal derived hydrocarbons.
Kuwano
Y
Y
Research Center for Environmental Quality Control, Kyoto University 1-2 Yumihama, Otsu 520-0811, Japan.
Shimizu
Y
Y
D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors; D003031:Coal; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D008970:Molecular Weight; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D016999:Sulfur-Reducing Bacteria / Q000502:physiology*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D003031:Coal; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical