Effects of carbon source on N2O production in the process of simultaneous nitrification and denitrifica-tion via nitrite by aerobic granular sludge

2016 ◽  
Vol 1 (2) ◽  
pp. 10 ◽  
Author(s):  
Hong Liang ◽  
Xue Li ◽  
Shanshan Wang ◽  
Dawen Gao

A sequencing batch reactor (SBR) was used to study the effect of carbon source (C6H12O6 and CH3COONa) and C/N ratio (C/N=4:1 and C/N=7:1) on the production of nitrous oxide (N2O) in the process of simultaneous nitrifica-tion and denitrification via nitrite (short-cut SND) by aerobic granular sludge and the removal efficiency of nitrogen under low dissolved oxygen (DO). The results showed that short-cut SND occurred in this system, and the removal ef-ficiency of total nitrogen (TN) at C6H12O6 and CH3COONa were 28.93 % and 41.19 %, respectively. However, the production of N2O significantly increased when CH3COONa was used as a carbon source. In addition, the rate of N2O release when CH3COONa was a carbon source was 8.34 times the rate when C6H12O6 was the carbon source. With the increase of C/N, removal rate of TN and the efficiency of the short-cut SND were increased. The removal efficiency of TN at C/N=7:1 was 90.33%, which was 2.19 times at C/N=4:1. The percentage of short-cut SND at C/N=4:1 and C/N=7:1 were 87.47% and 95.97%, respectively. The release rate of N2O from the original 1.14 mg/(g • min) decreased to 0.10 mg/(g • min) after increased the C/N from 4:1 to 7:1.

2014 ◽  
Vol 955-959 ◽  
pp. 339-342 ◽  
Author(s):  
Xin Gang Wang ◽  
Bing Lin ◽  
Yu Bin Tang ◽  
Hai Feng Chen

The aerobic granular sludge (AGS) was used to remove pollutants (COD, NH3-N, TN and TP) in wastewater under different salinity in a sequencing batch reactor (SBR). The results show that: the salinity has a significant impact on the removal of COD and TN, and the removal rate declines to 60% and 56% respectively when the water salinity rises from 5g/L to15g/L. The NH3-N removal is not much affected by the salinity, and the average removal rate is 75%. TP removal rate changes little at low-salted environment (the salinity less than 10g/L), however, the rate declines heavily when the salinity gets more than 10g/L, 70% in 10g/L and 57% in 15g/L.


2013 ◽  
Vol 295-298 ◽  
pp. 1438-1441
Author(s):  
Rui Ling Bao ◽  
Lian Qing Xue ◽  
Xiao Ju Yan ◽  
Shui Li Yu

An aerobic granular sludge sequencing batch reactor was carried out at low temperature (101oC) to understand the characteristics of nitrogen removal. The results indicated that nitrification via nitrite could be achieved with an average nitrosation rate of 97.7%. Influent C/N ratio was an important factor influencing the accumulation of nitrite in the effluent. In the experinment, the reactor exhibited a higher removal efficiency for COD with the effluent concentration of COD ranged from 88.2% to 91.8%. In phase I which C/N ratio was 20:1, effluent concentration of ammonium was about 12.9mg/L with the removal efficiency of 77.0%. As the C/N ratio was reduced to 15:1 and 10:1, the effluent concentration of ammonium was around 0.5 mg/L. At the same time, nitrite in the effluent reached up to 21.0 mg/L when the influent COD concentration was induced from 1120mg/L to 560 mg/L with C/N ratio induced from 20:1 to 10:1, however nitrate concentration was remained around 0.4 mg/L throughout the whole experinment.


2012 ◽  
Vol 518-523 ◽  
pp. 473-477
Author(s):  
Xia Zhao ◽  
Hui Xia Feng ◽  
Feng Jiang ◽  
Na Li Chen ◽  
Xiao Chun Wang

In sequencing batch reactor aerobic granular sludge was cultivated, and the influence of influent C/N ratio to aerobic granular sludge was studied. The results showed that the granulation and the settling ability of the sludge were poor in high C/N, however, low C/N was beneficial to the accumulation of microorganism in reactor and MLSS could reach to as high as 8740 mg/L. Lower C/N ratio would lead to increase of particle size and disintegrate of loose structure and overgrowth on filamentous microbe, these were disadvantage of the stability of the system. It was not obvious that influent C/N ratio affected on the organic removal. The COD removal maintained at 87% after the preliminary form particles were formed in reactor. When C/N ratio was 100:15~100:35, the phosphorus removal efficiency was good. If C/N ratio was too high or too low, the formation of sludge granulation would be affected in the process. The influence of C/N ratio to ammonia nitrogen removal efficiency was obvious. While C/N ratio was 100:10, granular sludge had good simultaneous nitrification and denitrification performance, and the average removal of ammonia nitrogen attained to 91%. But low C/N ratio was able to inhibit the activity of nitrifying bacteria and denitrifying bacteria. At that time, ammonia nitrogen removal rate declined sharply in the system.


2009 ◽  
Vol 60 (4) ◽  
pp. 1049-1054 ◽  
Author(s):  
S. López–Palau ◽  
J. Dosta ◽  
J. Mata-Álvarez

Aerobic granular sludge was cultivated in a sequencing batch reactor (SBR) in order to remove the organic matter present in winery wastewater. The formation of granules was performed using a synthetic substrate. The selection parameter was the settling time, as well as the alternation of feast-famine periods, the air velocity and the height/diameter ratio of the reactor. After 10 days of operation under these conditions, the first aggregates could be observed. Filamentous bacteria were still present in the reactor but they disappeared progressively. During the start-up, COD loading was increased from 2.7 to 22.5 kg COD/(m3 day) in order to obtain a feast period between 30 and 60 minutes. At this point, granules were quite round, with a particle diameter between 3.0 and 4.0 mm and an average density of 6 g L−1. After 120 days of operation, synthetic media was replaced by real winery wastewater, with a COD loading of 6 kg COD/(m3 day). The decrease of the organic load implied a reduction of the aggregate diameter and a density increase up to 13.2 g L−1. The effluent was free of organic matter and the solids concentration in the reactor reached 6 g VSS L−1.


RSC Advances ◽  
2016 ◽  
Vol 6 (18) ◽  
pp. 15201-15209 ◽  
Author(s):  
Fanghui Yuan ◽  
Chao Song ◽  
Xuefei Sun ◽  
Linrui Tan ◽  
Yunkun Wang ◽  
...  

BioSeNPs, which were produced by aerobic granular sludge in a sequencing batch reactor, could be used to remove cadmium from aqueous solution with high efficiency.


2009 ◽  
Vol 59 (12) ◽  
pp. 2371-2377 ◽  
Author(s):  
Q. Yang ◽  
X. H. Liu ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
H. W. Sun ◽  
...  

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.


2015 ◽  
Vol 13 (3) ◽  
pp. 746-757 ◽  
Author(s):  
Bei Long ◽  
Chang-zhu Yang ◽  
Wen-hong Pu ◽  
Jia-kuan Yang ◽  
Guo-sheng Jiang ◽  
...  

Mature aerobic granular sludge (AGS) was inoculated for the start-up of a pilot-scale sequencing batch reactor for the treatment of high concentration solvent recovery raffinate (SRR). The proportion of simulated wastewater (SW) (w/w) in the influent gradually decreased to zero during the operation, while volume of SRR gradually increased from zero to 10.84 L. AGS was successfully domesticated after 48 days, which maintained its structure during the operation. The domesticated AGS was orange, irregular, smooth and compact. Sludge volume index (SVI), SV30/SV5, mixed liquor volatile suspended solids/mixed liquor suspended solids (MLVSS/MLSS), extracellular polymeric substances, proteins/polysaccharides, average particle size, granulation rate, specific oxygen utilization rates (SOUR)H and (SOUR)N of AGS were about 38 mL/g, 0.97, 0.52, 39.73 mg/g MLVSS, 1.17, 1.51 mm, 96.66%, 47.40 mg O2/h g volatile suspended solids (VSS) and 8.96 mg O2/h g VSS, respectively. Good removal effect was achieved by the reactor. Finally, the removal rates of chemical oxygen demand (COD), total inorganic nitrogen (TIN), NH4+-N and total phosphorus (TP) were more than 98%, 96%, 97% and 97%, respectively. The result indicated gradually increasing the proportion of real wastewater in influent was a useful domestication method, and the feasibility of AGS for treatment of high C/N ratio industrial wastewater.


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