Cultivation and start-up of A2N denitrifying phosphorus and nitrogen removal system

Author(s):  
Li Xu ◽  
Andong Ge ◽  
Mingfen Niu ◽  
Hao Wang
2012 ◽  
Vol 610-613 ◽  
pp. 1454-1458
Author(s):  
Ming Fen Niu ◽  
Hong Jing Jiao ◽  
Li Xu ◽  
Yan Yu ◽  
Jian Wei

A2N is two-sludge system, by using the method that first bringing up the cultivation of denitrifying phosphorus removing bacteria (DPB) and nitrification biofilm separately then connecting them, which can start up A2N system successfully. Nitrification biofilm was cultivated in a sequencing batch reactor (SBR). After 30 days, NH4+-N effluent concentration steadily stayed below 0.5mg·L-1.In another SBR, the activated sludge for the enrichment of DPB is from the anaerobic tank, which was firstly operated under anaerobic/aerobic (A/O) condition. After 20 days, PAOs was successfully enriched. Then, the activated sludge was conducted under anaerobic/anoxic/aerobic (A/A/O) condition, maintaining the anaerobic time, gradually increased anoxic time and induced aerobic time. After 30 days DPB was successfully enriched, two phases totally take 50 days. The removal efficiency of total nitrogen and phosphorus are above 85 % and 95 %, so that A2N system was started up successfully.


1996 ◽  
Vol 33 (12) ◽  
pp. 109-116 ◽  
Author(s):  
Ulf Nyberg ◽  
Bengt Andersson ◽  
Henrik Aspegren

Methanol and ethanol have been used for three years as external carbon sources in a nutrient removal system based on pre-precipitation and post-denitrification in a single sludge activated sludge plant. Based on these long-term experiences it has been shown that the nitrogen standards of 8 mg N/l in the effluent wastewater can be met with both carbon sources. The process entails operational flexibility and the possibility to optimize the nitrogen removal due to seasonal variations in influent wastewater characteristics. Very high specific nitrate utilization rates were measured in the system with the use of external carbon sources. Rates of around 10 mg N/g VSS.h were reached with ethanol and around 3 mg N/g VSS.h with methanol. These rates were much higher than experienced in a pre-denitrification system with the use of the influent organic material as carbon source for denitrification. A start-up with the addition of ethanol led to a direct response of the system while a start-up with methanol resulted in a much longer adaptation period before full effect of the carbon source added was reached.


1999 ◽  
Vol 40 (8) ◽  
pp. 145-151 ◽  
Author(s):  
Liliana Borzacconi ◽  
Gisela Ottonello ◽  
Elena Castelló ◽  
Heber Pelaez ◽  
Augusto Gazzola ◽  
...  

The performance of a bench scale upflow sludge bed (USB) denitrifying reactor was evaluated in order to integrate it into a C and N removal system for Sanitary Landfill Leachate. The raw leachate used presented COD and NH4-N average values of 30000 mg/l and 1000 mg/l, respectively. The complete system comprises in addition an UASB reactor and a nitrifying RBC. A portion of the aerobic reactor effluent was recycled into the denitrification stage and some raw leachate was also added as an additional C source. In order to obtain operating parameters the denitrifying reactor was operated alone. Sludge from an aerobic reactor (RBC) treating raw leachate was used as inoculum. Shortly after the start up, good granulation of the sludge bed was observed. Using raw leachate and UASB outlet as carbon sources with COD/NO3-N ratios of 4 and 12, respectively, denitrification efficiencies of about 90% were reached. A sludge yield of 0.16 gVSS/gCODremoved was obtained operating with raw leachate. For the anoxic reactor operating in the complete system, denitrification efficiencies of 90% were also achieved. A nitrogen gas recycle was a successful way to avoid frequently observed sludge bed rising problems.


2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.


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