[Cultivation of aerobic granular sludge and characterization of nitrobenzene-degrading].

The highly efficient nitrobenzene degrading aerobic mixed microbe was cultivated from activated sludge originated from Nanjing chemical plant and it was found that aerobic granular sludge could be formed through the flask trial. The nitrobenzene-degrading experiment was conducted with the obtained aerobic granular sludge. Results showed that the mixed microbe could utilized nitrobenzene as the sole source of carbon and nitrogen for its growth. The optimum growth conditions for the bio-degradation of nitrobenzene were pH 7.0 and 28 degrees C. The adaptive period was no more than 6 hours and its degrading efficiency was highest when the initiative concentration of nitrobenzene was 600 mg x L(-1). The mixed microbe could completely degrade nitrobenzene (600 mg x L(-1)) within 24 hours and the maximum degradation rate of nitrobenzene was 28.8 mg x (L x h)(-1). It will be possible that aerobic granular sludge can be used to degrade the organics such as nitrobenzene contained in the industrial waste water.