Efficient recovery of carbon, nitrogen, and phosphorus from waste activated sludge

2013 ◽  
Vol 68 (4) ◽  
pp. 916-922 ◽  
Author(s):  
Yinguang Chen ◽  
Xiong Zheng ◽  
Leiyu Feng ◽  
Hong Yang
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Precipitation Method ◽  
Waste Activated Sludge ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Fermentation Time ◽  
Fermentation Liquid ◽  
Efficient Recovery ◽  
Biological Nitrogen

Carbon, nitrogen, and phosphorus need to be recovered to reduce the environmental impact of waste activated sludge (WAS). In this study the improved short-chain fatty acid (SCFA) production from WAS by the addition of kitchen waste to adjust the ratio of carbon to nitrogen (C/N), and the efficient recovery of nitrogen and phosphorus from the fermentation liquid were reported. Firstly, the optimum conditions for SCFA production were found to be pH 8, temperature 35 °C, C/N ratio 21 mg-C/1 mg-N, and fermentation time 6 d, using the response surface methodology. After alkaline fermentation, the struvite precipitation method was applied to efficiently and simultaneously recover the released ammonia and phosphorus from the fermentation liquid. Finally, the fermentation liquid was used as the additional carbon source for biological nitrogen and phosphorus removal. It was observed that, compared with acetic acid, the use of fermentation liquid as carbon source showed greater removal efficiencies of total nitrogen and total phosphorus.

Nutrient Removal: On-Line Measurements and Control Strategies

1993 ◽  
Vol 28 (11-12) ◽  
pp. 549-560 ◽  
Author(s):  
Dines E. Thornberg ◽  
Marinus K. Nielsen ◽  
Klaus L. Andersen
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Control Strategies ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
On Line ◽  
Biological Nitrogen ◽  
And Control ◽  
New Strategies ◽  
Phase Length

New control strategy principles with respect to nitrogen and phosphorus removal in activated sludge plants are described. The principles include control of phase length and oxygen set point based on criteria functions and continuous on-line measurements of ammonium, nitrate, phosphate and pH. Five case studies are stated which describe improvements in biological nitrogen and phosphorus removal and in chemical phosphorus removal at activated sludge plants ranging from 5000 to 220000 population equivalents (0.25 to 11 MGD). The improvements due to the new strategies are basically a reduction of nutrients in the effluent and a reduction in the amount of chemicals and electricity consumed.

Removal of nitrogen and phosphorus using a new biofilm-activated-sludge system

1996 ◽  
Vol 34 (1-2) ◽  
pp. 315-322 ◽  
Author(s):  
J. X. Liu ◽  
J. W. van Groenestijn ◽  
H. J. Doddema ◽  
B. Z. Wang
Keyword(s):  
Activated Sludge ◽  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Domestic Wastewater ◽  
Optimum Conditions ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
The Mean ◽  
Scale Experiment ◽  
Biological Nitrogen

This paper describes a laboratory scale experiment using a combined biofilm and activated sludge process to enhance biological nitrogen and phosphorus removal. In the system, fibrous carriers were packed in an anoxic tank for the attached growth of denitrifying bacteria and the sludge of the clarifier was returned to the anaerobic tank to release phosphate. In this configuration, nitrification, denitrification and phosphorus removal could be performed at their respective optimum conditions. The influent was domestic wastewater; the mean concentrations of COD, NH4-N and total phosphorus in the influent were about 319 mg/l, 60 mg/l and 10 mg/l respectively. At a total HRT of the system of 20-30 hours, based on the influent flow of the system, and a temperature of 10-15°C, the mean concentrations of COD, NH4-N, NO3-N, NO2-N and total phosphorus in the effluent were about 39.4 mg/l, 1.3 mg/l, 13.4 mg/l, 0.6 mg/l, and 0.8 mg/l respectively.

Another carbon source for BNR system

1996 ◽  
Vol 34 (1-2) ◽  
pp. 363-369 ◽  
Author(s):  
E. Choi ◽  
H. S. Lee ◽  
J. W. Lee ◽  
S. W. Oa
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Organic Loading ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Loading Rates ◽  
Study Results ◽  
Removal Efficiencies ◽  
Low Strength

It has been known wastewater with low COD/TKN ratio produces higher effluent NO3-N and adversely affects poly P microbes returning it to an anaerobic stage in BNR systems. Nightsoil applicability to return activated sludge line to minimize NO3-N effect to poly P microbes in anaerobic stage was examined with laboratory BNR systems operated at 20°C. The study results indicated nightsoil application could improve nitrogen and phosphorus removal efficiencies both with low strength settled municipal and piggery wastes presenting low COD/TKN ratios of 6 and 2.2, respectively. Even organic loading rates increased to 20 to 60% due to nightsoil application, the effluent COD increased only 10 to 20%. This would suggest nightsoil can be used as another carbon source and nightsoil application to return activated sludge line can be another alternative modification to improve BNR systems.

Evolution of an ASM2d-like model structure due to operational changes of an SBR process

2006 ◽  
Vol 53 (12) ◽  
pp. 237-245 ◽  
Author(s):  
G. Sin ◽  
P.A. Vanrolleghem
Keyword(s):  
Activated Sludge ◽  
Pilot Scale ◽  
Model Structure ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Biological Behaviour ◽  
System A ◽  
Biological Nitrogen ◽  
Hydrolysis Of ◽  
Activated Sludge Systems

To model biological nitrogen and phosphorus removal systems with an affordable complexity, the ASM2d model structure is based on many assumptions. In this study, some of these assumptions, however, were observed to become invalid when the biological behaviour in the system altered in response to changes in the operation of the system, a pilot-scale N and P removing SBR. Particularly, the three applied operational scenarios resulted in three distinctive responses in the SBR, namely pronounced limitation of the hydrolysis of the organic nitrogen, nitrite build-up during aerobic conditions and also nitrite build-up during anoxic conditions. This shows that even for the same system with the same influent wastewater composition, the model structure of the ASM2d does not remain constant but adapts parallel to dynamic changes in the activated sludge community. On the other hand, the three calibrated ASM2d models still lacked the ability to entirely describe the observed dynamics particularly those dealing with the phosphorus dynamics and hydrolysis. Understanding the underlying reasons of this discrepancy is a challenging task, which is expected to improve the modelling of bio-P removing activated sludge systems.

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