中文摘要：

采用聚乙二醇（PEG）和海藻酸钠（SA）作为混合固定化载体材料对硝化细菌进行包埋固定化。结果表明,PEG和SA质量分数分别为6%和4%时,其溶液黏稠度、成球效果及机械强度、传质性能等方面都均为最佳。另外,固定化小球扫描电镜显示球体为外密内疏的结构,这满足体内细胞泄漏少、外面细胞难以进入的条件。将所得最佳性能的固定化小球与游离菌体进行模拟废水降解对比试验,经过7d处理后废水中氨氮和亚硝态氮质量浓度都明显下降,且固定化颗粒的降解率要明显高于游离菌株,此时氨氮的去除率为90%,亚硝态氮去除率为80%。

英文摘要：

The aim of this paper is to disclose the optimized immobilization conditions by using PEG and SA as a kind of mixed carrier to immobilize the nitrite bacteria and nitrifying bacteria. As is known,in recent years,the immobilization technique has been widely used for sewage treatment,especially in the nitrogen sewage treating field.It is just for this purpose that we would like to solve the problem in treating the nitrogen-polluted sewage in a biological approach. In comparison with the physical and chemical approaches,bioremediation has shown less impact on the human health as well as the environment. It is just for the above reasons that we prefer to isolate the nitrite bacteria and nitrifying bacteria from the activated sludge and test their 16 S r DNA sequences. It is also for this need that we have been trying to attempt to create the optimized immobilization conditions and optimized degradation conditions for testing the experimental immobilized particles. Besides,we have also tested the degradation rate of the immobilized strains and free strains. The 16 S r DNA sequences of stems indicate that nitrite bacteria belong to Klebsiella pneumoniae and nitrifying bacteria affiliated to Raoultella ornithinolytic. Analyzing the solution viscosity,the particle shape and mechanical strength,we have found that the immobilized particles can reach the optimal conditions when the mass fraction of PEG is equal to 6% with SA being 4%. Observing external and internal structure of the immobilized particles by SEM,it can be found that the particles have a structure of surface-densification and inside-loosing,which is propitious to the movement of oxygen,water and substrate in addition to being advantageous for the growth and propagation of bacteria inside the carrier. Changing such conditions as those of temperature,p H value and DO concentration,it would be possible to test the effects of the factors on the nitrogen removal efficiency of the two immobilized bacterium particles more effectively. What is more,cultivating each s