Study On Aerobic Biodegradation Of Unsymmetrical Dimethylhydrazine

Unsymmetrical Dimethylhydrazine (UDMH) is choiceness capability hydrazine fuel, to be used as propellant of missiles, satellites and spacecraft launching. UDMH can bring organisms about cancer because of it's toxicity.The seed sludge geted form municipal sewage treatment plant.This seed sludge must be domesticated before it can degradate the UDMH. UDMH can be removed 98% after 40 days domestication.The aerobic degradation bacteria of UDMH can be isolated from the domestication activated sludge. The method of flat line and selectivity culture medium adapted in the isolation. The kinetics parameter of aerobic biodegradation bacteria of UDMH was mensurated by the method of kinetics. By relation calculation, the Kinetics Threshold Concentration is 0.055mg·L -1which was confirmed by batch experiments. In the confirmation experiments, after 12 hours of degradation, the concentration of UDMH can reduce to 0.055 mg·L-1 when the began concentration of UDMH was 10, 20,30 or 40 mg·L-1.The aerobic biodegradation bacteria of UDMH can grow quickly when the environmental pH is 7.2, the temperature is 25℃, stirring speed is 80 r·min-1, and UDMH concentration is 158 mg·L-1.The tolerance range of UDMH aerobic degradation bacteria with environment temperature is 5 to 50℃, and the tolerance range of environment pH is 4 to 12.Nitrosodimethylamine did't be detected in the process of UDMH aerobic biodegradation.