[Immobilized ammonia-oxidizing bacteria Comamonas aquatic LNL3 and its partial nitrification characterization].

A new kind of ammonia-oxidizing bacteria (AOB)-Comamonas aquatic LNL3 was screened out and immobilized by Poly (HEA)-Poly (HEMA) copolymer carrier using irradiation techniques. Four kinds of impact factors on short-cut nitrification, including temperature, pH, DO and free ammonia (FA) concentration had been investigated. The result showed that AOB-Comamonas aquatic LNL3 had short-cut nitrification capability and the optimal temperature, pH, DO and FA concentration were 30 degrees C, 8.5, 4.03 mg/L and 9 mg/L respectively. Corresponding to above results, ammonia nitrogen removal rate and short-cut nitrification efficiency were 93.52%, 94.73%; 79.74%, 94.67%; 91.17%, 94.66% and 90%, 94.4% respectively.

[Ecological engineering experiment for Jinshan Lake in Zhenjiang base on techniques of immobilized nitrogen cycling bacteria].

Nitrogen cycling bacteria, including ammonifying, nitrobacteria, nitrosobacteria and denitrifying bacteria were screened, carrier was made and immobilized nitrogen cycling bacteria (INCB) was prepared. The results demonstrated that ammonifying, nitrobacteria, nitrosobacteria and denitrifying bacteria were increased markedly in the experimental areas and root zone of aquatic plants by releasing of INCB. The results also showed that the average removal efficiencies for total N (TN), NH4(+) -N, NO3(-) -N and NO2(-) -N were 44.70%, 67.17%, 31.79% and 74.21%, respectively. Furthermore, NH4(+) -N, total N (TN) reached the National Standard II and IV for surface water, respectively. With INCB, local lake water quality could improve. Therefore, the technique of INCB could play an important role for remedying and rehabilitating in desertification water.

[Stability of short-cut nitrification using immobilized ammonia-oxidizing bacteria].

The ammonia-oxidizing bacteria were immobilized by copolymer with cell proliferation technology. The effects of NH(4+) -N load, HRT, free ammonia (FA) and organic matter on short-cut nitrification process were studied. The results showed that when influent NH(4+) -N load were 100 mg/L, 150 mg/L and 200 mg/L respectively, effluent NH(4+) -N concentration was less than 10 mg/L. When the system run for 3 h, 6 h and 12 h, corresponding to influent NH(4+) -N concentration of 25.8 mg/L, 51.1 mg/L and 93.3 mg/L respectively, NH(4+) -N concentration was low in effluent with high short-cut nitrification efficiency. The HRT could be adjusted to optimize the system operation with variation of influent NH(4+) -N concentration. The results also indicated that the ammonia-oxidizing bacteria were restrained while free ammonia concentration was over 9 mg/L. The activity of the ammonia-oxidizing bacteria could be enhanced under existence of low-molecular-weight organic compounds, but the short-cut nitrification efficiency was little affected. In addition, the short-cut nitrification and denitrification could be realized with existence of organic compounds during the experiment.