Changlun Chen1, Amjad Ali1, Junfeng Su2, Yue Wang1, Tinglin Huang3, Jing Gao1. 1. School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China. 2. School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Green Building in West China, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address: sjf1977518@sina.com. 3. School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Green Building in West China, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Abstract
A denitrifying strain with high efficiency at low carbon to nitrogen (C/N) ratio of 2.0 was isolated and characterized. It belongs to the genus Pseudomonas. Scanning electron microscopy (SEM) showed that GF2 was rod-shaped. The nitrate removal efficiency reached up to 92.41% (1.85 mg L-1 h-1) with the C/N ratio of 2.0 and the nitrite accumulation eventually decreased to 0.88 mg L-1. By response surface method (RSM) method, three reaction conditions of strain GF2 were optimized, including pH, C/N ratio, and nitrate concentration. Nitrogen balance and gas detection revealed that 88.03% of nitrogen was removed in gaseous form (included 98.80% nitrogen gas), which confirmed its efficient denitrification ability and pathway. 3D fluorescence spectrum (3D-EEM) manifested that in the absence of organic matter, strain GF2 can utilize extracellular polymeric substance (EPS) as carbon source for efficient denitrification. This research strived to provide new research ideas for low C/N ratio sewage treatment.
A denitrifying strain with high efficiency at low carbon to n class="Chemical">nitrogen (C/N) ratio of 2.0 was isolated and characterized. It belongs to the genus Pseudomonas. Scanning electron microscopy (SEM) showed that GF2 was rod-shaped. The nitrate removal efficiency reached up to 92.41% (1.85 mg L-1 h-1) with the C/N ratio of 2.0 and the nitrite accumulation eventually decreased to 0.88 mg L-1. By response surface method (RSM) method, three reaction conditions of strain GF2 were optimized, including pH, C/N ratio, and nitrate concentration. Nitrogen balance and gas detection revealed that 88.03% of nitrogen was removed in gaseous form (included 98.80% nitrogen gas), which confirmed its efficient denitrification ability and pathway. 3D fluorescence spectrum (3D-EEM) manifested that in the absence of organic matter, strain GF2 can utilize extracellular polymeric substance (EPS) as carbon source for efficient denitrification. This research strived to provide new research ideas for low C/N ratio sewage treatment.