热冲击法实现包埋活性污泥稳定亚硝化

亚硝化是一种节能的工艺，在处理高氨氮质量浓度和低Ｃ/Ｎ比污水时具有较高的可行性。本研究通过热冲击的方式处理包埋活性污泥，成功实现了NO2--N的积累。研究中发现，在60℃温度下热冲击10min，亚硝酸盐氧化菌(Nitrite oxidizing bacteria，NOB)活性就将完全消失，而氨氧化菌(Ammonia oxidizing bacteria，AOB)仍有一定活性。PCR-DGGE发现，热冲击后包埋颗粒内残留的NOB主要是Candidatus Nitrospira defluvii，只有当生物量达到一定值后时才能显现出硝化性能。研究还对60℃和70℃热冲击后的包埋颗粒进行了连续流实验，发现热冲击后的包埋颗粒均能维持稳定的亚硝化，但温度越高，达到亚硝化所需的时间越长。在维持65d的稳定亚硝化后，反应器内开始出现NO3--N积累，重新对包埋颗粒进行热冲击，反应器可以再次实现稳定的亚硝化。

Stably Nitritation Process Using Heat-shocked Immobilized Activated Sludge

Nitritation is an energy-saving process and is highly feasible for treating polluted water with a high mass concentration of ammonia-nitrogen and a low C/N ratio. In this study, the heat-shock method was used to treat immobilized activated sludge, NO2--N accumulation was successfully achieved. Investigation of the temperature and processing time of the heat shock method revealed that nitrite oxidizing bacteria (Nitrite oxidizing bacteria, NOB) was completely deactivated when heated at 60˚ for 10 min, while ammonia oxidizing bacteria (Ammonia oxidizing bacteria, AOB) still exhibited some activity. PCR-DGGE was used, and revealed that NOB residue after heat shock were Candidatus Nitrospira defluvii, which only when the biomass reach a certain value to appear nitrification performance. 2 different temperatures were used to heat shock the immobilized granules, after which continuous-flow experiments were conducted. It was discovered that all 2 groups of heat shocked immobilized granules could remain stably nitritation, but the higher the temperature the longer the time was required for start stable nitritation. however, NO3--N accumulation occurred in the reactor after stably nitritation for 65d, Therefore, the immobilized granules were heat-shocked again, and nitrite nitrogen accumulation recurred in the reactor.