scholarly journals Litter Decomposition and Soluble Carbon, Nitrogen, and Phosphorus Release in a Forest Ecosystem

2011 ◽  
Vol 01 (03) ◽  
pp. 86-96 ◽  
Author(s):  
Maria L. Silveira ◽  
Konda R. Reddy ◽  
Nicholas B. Comerford
1993 ◽  
Vol 28 (11-12) ◽  
pp. 513-521 ◽  
Author(s):  
Kousei Sasaki ◽  
Yasuji Yamamoto ◽  
Kazushi Tsumura ◽  
Shigeru Hatsumata ◽  
Masahiro Tatewaki

The 2-tank intermittent aeration method is an anaerobic-aerobic activated sludge process of time-sharing type in which 2 complete mixing reaction tanks are connected in series, and aeration and agitation are periodically repeated in each tank. We have developed a new control system for the process which can secure anaerobic, anoxic and aerobic conditions through a combination of DO and ORP-Bending-point (corresponding to termination of denitrification) emergence time control. In the 1st tank, nitrification and phosphorus uptake occur in the aeration period, followed by denitrification and phosphorus release in the agitation. The 2nd tank performs nitrification and phosphorus uptake in the aeration and denitrification in the agitation. One cycle of aeration and agitation is approximately 2 hours. This control system was applied to the test plant (influent flow rate: 225 I/day) for two months under the conditions of HRT 16 hours and temperature 20 ±2 °C. We achieved stable and high removal ratios: TOC 94.9 %, T-N 89.4 %, and T-P 95.5 %. We also investigated the mechanisms of nitrogen and phosphorus removal and their material balance.


Biotropica ◽  
2001 ◽  
Vol 33 (2) ◽  
pp. 229
Author(s):  
A. B. Kwabiah ◽  
N. C. Stoskopf ◽  
R. P. Voroney ◽  
C. A. Palm

2004 ◽  
Vol 50 (10) ◽  
pp. 163-170 ◽  
Author(s):  
R.J. Zeng ◽  
R. Lemaire ◽  
Z. Yuan ◽  
J. Keller

Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic–anoxic enhanced biological phosphorus removal (EBPR) are two processes that can significantly reduce the COD demand for nitrogen and phosphorus removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and phosphorus removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic–aerobic mode with a low dissolved oxygen concentration (DO, 0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification and phosphorus removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHA), accompanied with phosphorus release. In the subsequent aerobic stage, PHA was oxidized and phosphorus was taken up to less than 0.5 mg/L at the end of the cycle. Ammonia was also oxidised during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis found that the final denitrification product was mainly nitrous oxide (N2O) not N2. Further experimental results demonstrated that nitrogen removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms rather than denitrifying polyphosphate-accumulating organisms were responsible for the denitrification activity.


PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e84101 ◽  
Author(s):  
Hao Chen ◽  
Shaofeng Dong ◽  
Lei Liu ◽  
Chuan Ma ◽  
Tao Zhang ◽  
...  

2012 ◽  
Vol 588-589 ◽  
pp. 55-58
Author(s):  
Yong Feng Li ◽  
Jian Yu Yang ◽  
Guo Cai Zhang

Simulate sewage were used in an anaerobic-anoxic-aerobic biological nutrient removal system(A2O process), by observing the pHs in different compartments and its reflected changes in nitrogen and phosphorus removal, studied on the effects of different pHs on the removal of pollutants. The experiments indicates that the anaerobic phosphorus release showed the main performance of the decline of pH, denitrification in anoxic zone caused the rise of pH, uptake of phosphate in the aerobic zone mainly caused the continuous rise of pH. There is no evidently changes in COD removal, ammonia nitrogen get the highest removal as the pH value was between 8.0-8.5, when pH was at 6.5-7.5, the TN have the maximum removal rate, TP can keep in a high level when the pH was above 6.0.


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