Microsensor measurements and fluorescence in situ hybridization (FISH) analysis were combined to investigate the microbial populations and activities in a laboratory-scale sequencing batch reactor (SBR) for comple...Microsensor measurements and fluorescence in situ hybridization (FISH) analysis were combined to investigate the microbial populations and activities in a laboratory-scale sequencing batch reactor (SBR) for completely autotrophic nitrogen removal over nitrite (CANON). Fed with synthetic wastewater rich in ammo- nia, the SBR removed 82.54-5.4% ofinfluent nitrogen and a maximum nitrogen-removal rate of 0.52kgN.m 3.d-l was achieved. The FISH analysis revealed that aerobic ammonium-oxidizing bacteria (AerAOB) Nitrosomonas and anaerobic ammonium-oxidizing bacteria (AnAOB) dominated the community. To quantify the microbial activities inside the sludge aggregates, microprofiles were measured using pH, dissolved oxygen (DO), NH+, NO+ and NO3 microelectrodes. In the outer layer of sludge aggregates (0-700 μm), nitrite-oxidizing bacteria (NOB) showed high activity with 4.1 gmol-cm3+ h-1 of maximum nitrate production rate under the condition of DO concentration higher than 3.3 mg. L 1. Maximum AerAOB activity was detected in the middle layer (depths around 1700 μm) where DO concentration was 1.1 μg. L-1. In the inner layer (2200-3500μm), where DO concentration was below 0.9 mg. L-1, AnAOB activity was detected. We thus showed that information obtained from microscopic views can be helpful in optimizing the SBR performance.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 51108367), Specialized Research Fund for the Doctoral Program of Higher Education (No. 20116120120009), Natural Science Foundation of Shaanxi Province (No. 2014JQ7243) and innovative research team of Xi'an University of Architecture and Technology.
文摘Microsensor measurements and fluorescence in situ hybridization (FISH) analysis were combined to investigate the microbial populations and activities in a laboratory-scale sequencing batch reactor (SBR) for completely autotrophic nitrogen removal over nitrite (CANON). Fed with synthetic wastewater rich in ammo- nia, the SBR removed 82.54-5.4% ofinfluent nitrogen and a maximum nitrogen-removal rate of 0.52kgN.m 3.d-l was achieved. The FISH analysis revealed that aerobic ammonium-oxidizing bacteria (AerAOB) Nitrosomonas and anaerobic ammonium-oxidizing bacteria (AnAOB) dominated the community. To quantify the microbial activities inside the sludge aggregates, microprofiles were measured using pH, dissolved oxygen (DO), NH+, NO+ and NO3 microelectrodes. In the outer layer of sludge aggregates (0-700 μm), nitrite-oxidizing bacteria (NOB) showed high activity with 4.1 gmol-cm3+ h-1 of maximum nitrate production rate under the condition of DO concentration higher than 3.3 mg. L 1. Maximum AerAOB activity was detected in the middle layer (depths around 1700 μm) where DO concentration was 1.1 μg. L-1. In the inner layer (2200-3500μm), where DO concentration was below 0.9 mg. L-1, AnAOB activity was detected. We thus showed that information obtained from microscopic views can be helpful in optimizing the SBR performance.