ABSTRACT
Increasing attention has been given to anaerobic biodegradation of organic pollutants in contaminated subsurface sediments and groundwater. Fermentation, as a strictly anaerobic process without any external electron acceptor participating, however, has been ignored. The sequential anaerobic biodegradation of phenol from nitrate- through sulfate- reduction to methane production was investigated based on laboratory microcosm experiments under a simulated condition of contaminated groundwater. A highest phenolic degradation rate was achieved during the methanogenic process. Hydrogen and methane were found accumulated in the headspace of microcosms, even from highly contaminated groundwater and sediments. It suggested fermentation process could play an important role in natural attenuation of organic pollutants in groundwater and sediments.
