Nitrogen Removal from an Aerobically Digested Domestic Wastewater using Anoxic/Oxic (A/O) Reactor Packed with Non-woven Filter Materials

2013 ◽  
Vol 29 (1) ◽  
pp. 23-32
Author(s):  
John Leju Celestino LADU ◽  
Ting Ting WEI ◽  
Xiwu LU ◽  
Meiling ZHANG
2011 ◽  
pp. 285-296
Author(s):  
M. Ruscalleda Beylier ◽  
M.D. Balaguer ◽  
J. Colprim ◽  
C. Pellicer-Nàcher ◽  
B.-J. Ni ◽  
...  

2006 ◽  
Vol 27 (1) ◽  
pp. 22-36 ◽  
Author(s):  
Jeremy Fontenot ◽  
Dorin Boldor ◽  
Kelly A. Rusch

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Yu Huang ◽  
Yongzhen Peng ◽  
Donghui Huang ◽  
Jiarui Fan ◽  
Rui Du

A partial-denitrification coupling with anaerobic ammonium oxidation (anammox) process (PD/A) in a continuous-flow anoxic/oxic (A/O) biofilm reactor was developed to treat carbon-limited domestic wastewater (ammonia (NH4+-N) of 55 mg/L and chemical oxygen demand (COD) of 148 mg/L in average) for about 200 days operation. Satisfactory NH4+-N oxidation efficiency above 95% was achieved with rapid biofilm formation in the aerobic zone. Notably, nitrite (NO2−-N) accumulation was observed in the anoxic zone, mainly due to the insufficient electron donor for complete nitrate (NO3−-N) reduction. The nitrate-to-nitrite transformation ratio (NTR) achieved was as high as 64.4%. After the inoculation of anammox-enriched sludge to anoxic zones, total nitrogen (TN) removal was significantly improved from 37.3% to 78.0%. Anammox bacteria were effectively retained in anoxic biofilm utilizing NO2−-N produced via the PD approach and NH4+-N in domestic wastewater, with the relative abundance of 5.83% for stable operation. Anammox pathway contributed to TN removal by a high level of 38%. Overall, this study provided a promising method for mainstream nitrogen removal with low energy consumption and organic carbon demand.


2021 ◽  
Vol 6 (1) ◽  
pp. 101-112
Author(s):  
Sharjeel Waqas ◽  
Muhammad Roil Bilad ◽  
Zakaria B Man

Biological processes are extensively used for wastewater treatment because of low organic footprint, economically feasible, and high treatment efficiency. Rotating biological contactors (RBC), an attached growth biological process offers advantage of low operating cost, simple configuration and structure, reduced bionomical footprint and thus has been extensively employed for organics and nitrogen removal. In this study, RBC was used for the treatment of synthetic domestic wastewater operating at high hydraulic and organic loading rate to demonstrate the biological performance. The results showed that the RBC achieved a treatment efficiency for COD, ammonium, TN and turbidity of 70.2%, 95.2%, 70%, and 78.9 %, respectively. The efficient nitrogen removal and increased nitrate concentration signify the presence of nitrifying bacteria which actively degrade the nitrogen compounds through the nitrification process. Thus, this system is a sound alternative for both domestic and industrial wastewater treatment for decentralized applications.


1994 ◽  
Vol 30 (6) ◽  
pp. 73-81 ◽  
Author(s):  
N. F. Y. Tam ◽  
G. L. W. Leung ◽  
Y. S. Wong

A bench-scale study was undertaken to examine the effects of easily biodegradable organic carbon substrate on denitrification reaction and overall nitrogen removal from domestic wastewater under a modified sequencing batch reactor (SBR) system. The operation strategy of the SBR consisted of 0.75 h FILL, 8 h REACT separated into 4 h aerobic, 3 h anoxic and 1 h aerobic stages, 1.5 h SETTLE, 1 h DRAW and 0.75 h IDLE. Methanol, sodium acetate and sodium propionate, at the concentrations equivalent to theoretical COD values of 50, 100 and 150 mg O2 1−1 were used as the external carbon sources and added to the reactors prior to the anoxic stage. The study reveals that 4 h aerobic stage was sufficient to nitrify more than 98% NH4+-N and carbon addition caused slightly more nitrification than the control. Addition of sodium propionate at a low concentration (50 mg O2 1−1) significantly enhanced the denitrification process, the nitrate content in this reactor dropped to 3 mg 1−1 (89% reduction) at the end of the anoxic stage. Among the three substrate added at low dose, sodium propionate was the most effective carbon source, followed by acetate and the least effective one was methanol. When the carbon substrate were added at the doses of 100 and 150 mg O2 1−1, the denitrification rates of the acetate reactors recorded at the first hour of the anoxic stage were similar to those of the propionate's and significantly higher than the methanol reactors. When high dose (150 mg O2 1−1) of acetate or propionate was used, 95% reduction in wastewater NOx-N was found after 1 h anoxic stage while 3 h anoxic stage was required when the carbon dose was at 100 mg O2 1−1, indicating that addition of external carbon substrate at large quantity could shorten the denitrification time. However, the final effluent discharged from reactors treated with high dose of acetate and propionate contained more than 20 mg 1−1 BOD5 which might cause a contamination problem. Therefore, addition of sodium acetate or propionate at the concentration equivalent to theoretical COD values of 100 mg O2 1−1 appeared to be the most economical and reliable option.


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