scholarly journals N2O Reduction During Denitrifying Phosphorus Removal With Propionate as Carbon Source

Author(s):  
Li Cong ◽  
Qian Wang ◽  
Wenlin Jia

Abstract Denitrifying phosphorus removal was realized in sequencing batch reactors using different carbons sources (acetate, propionate, and a mixture of acetate/propionate). Nutrient removal and N2O production were investigated, and the factors affecting N2O production were explored. Nitrogen removal was 40.6% lower when propionate was used as the carbon source instead of acetate, while phosphorus removal was not significantly different. N2O production was greatly reduced when propionate was used as the carbon source instead of acetate. The emission factor in the propionate system was only 0.43%, while those in the acetate and mixed-carbon source system were 16.3% and 1.9%, respectively. Compared to the propionate system, ordinary heterotrophic organisms (i.e., glycogen-accumulating organisms) were enriched in the acetate system, explaining the higher N2O production in the acetate system. The lower nitrite accumulation in the propionate system compared to the acetate system was the dominant factor leading to the lower N2O production.

1999 ◽  
Vol 39 (6) ◽  
pp. 61-68 ◽  
Author(s):  
Klangduen Pochana ◽  
Jürg Keller

Experiments have been performed to gain an understanding of the conditions and processes governing the occurrence of SND in activated sludge systems. Sequencing batch reactors (SBRs) have been operated under controlled conditions using the wastewater from the first anaerobic pond in an abattoir wastewater treatment plant. Under specific circumstances, up to 95% of total nitrogen removal through SND has been found in the system. Carbon source and oxygen concentrations were found to be important process parameters. The addition of acetate as an external carbon source resulted in a significant increase of SND activity in the system. Stepwise change of DO concentration has also been observed in this study. Experiments to determine the effect of the floc size on SND have been performed in order to test the hypothesis that SND is a physical phenomenon, governed by the diffusion of oxygen into the activated sludge flocs. Initial results support this hypothesis but further experimental confirmation is still required.


2016 ◽  
Vol 73 (9) ◽  
pp. 2093-2100 ◽  
Author(s):  
Maryam Reza ◽  
Manuel Alvarez Cuenca

Simultaneous nitrification and denitrifying phosphorus removal was achieved in a single-sludge continuous flow bioreactor. The upright bioreactor was aligned with a biomass fermenter (BF) and operated continuously for over 350 days. This study revealed that unknown bacteria of the Saprospiraceae class may have been responsible for the successful nutrient removal in this bioreactor. The successive anoxic–aerobic stages of the bioreactor with upright alignment along with a 60 L BF created a unique ecosystem for the growth of nitrifier, denitrifiers, phosphorus accumulating organisms and denitrifying phosphorus accumulating organisms. Furthermore, total nitrogen to chemical oxygen demand (COD) ratio and total phosphorus to COD ratio of 0.6 and 0.034, respectively, confirmed the comparative advantages of this advanced nutrient removal process relative to both sequencing batch reactors and activated sludge processes. The process yielded 95% nitrogen removal and over 90% phosphorus removal efficiencies.


2012 ◽  
Vol 518-523 ◽  
pp. 440-443
Author(s):  
Yu Jiao Luo ◽  
Ling Feng Qiu ◽  
Yi Ming Chen ◽  
Jian Zhang

Based on DPBs (Denitrifying Phosphorus-removing Bacteria) obtained from a lab-scale SBR, a quinone profile system had been established to analyze quinones in sludge samples. There existed a positive correlation between the contents of UQ-8 extracted from the sludge samples and the denitrifying and phosphorus removal efficiency of the treating system. With quinone profiles taken as a new important index, it was evidently feasible to determine the removal effect.


2009 ◽  
Vol 60 (12) ◽  
pp. 3243-3251 ◽  
Author(s):  
Jianhua Guo ◽  
Shuying Wang ◽  
Huijun Huang ◽  
Yongzhen Peng ◽  
Shijian Ge ◽  
...  

Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite.


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