Abstract
Bacteria were isolated from the laboratory-scale activated sludge reactors operated using synthetic wastewater containing phenol as toxic organics, m-aminobenzoic acid (m-ABA) as a refractory organics and inorganic nutrients. These isolated bacteria which can utilize phenol and m-ABA as sole carbon source were used in order to clarify the effects of powdered activated carbon (PAC) on removal of the toxic and refractory organics. Biodegradation activity of phenol and m-ABA in the bacteria system with the addition of PAC was compared with that of the bacteria system with the addition of raw material of PAC (NAC) having no ability to adsorb, and the suspended bacteria system. The PAC accelerated biodegradability of phenol and m-ABA by the isolated bacteria much more than the NAC and suspended system. Number of bacteria in the systems with PAC and NAC by viable counts using phenol-selective medium and m-ABA-selective medium and number of bacteria on the surface of PAC and NAC by direct counts using SEM were almost same, irrespective of the difference in support media. Therefore, the addition of PAC would increase biodegradation activity of the toxic and refractory organics by the isolated bacteria. It was also found that biodegradation of m-ABA by isolated bacteria increase remarkably in the presence of phenol.
