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Simultaneous nitrification and denitrification of high ammonia nitrogen wastewater

Li Jiuyi,Wu Nianpeng,Liu Ying,Li Jin,

环境工程学报 , 2007,
Abstract: The effects of dissolved oxygen concentration and influent carbon to nitrogen ratio on nitrogen removal performance of a wastewater containing strength ammonia nitrogen were investigated in a sequencing batch reactor. Experimental results showed that the decrease of dissolved oxygen concentration led to short-cut simultaneous nitrification and denitrification and improved the total-nitrogen removal capacity. External carbon source uptake, PHB storage, aerobic PHB oxidation and simultaneous nitrification-denitrification processes were taken place in the operation of the reactor. PHB was demonstrated to be the electron donor of denitrification reaction in the simultaneous nitrification-denitrification process.
Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)  [PDF]
Massimo Raboni,Vincenzo Torretta,Giordano Urbini
Sustainability , 2013, DOI: 10.3390/su5093679
Abstract: The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because of the strong variations in the BOD 5/NO 3-N ratios and the unexpected abnormal accumulation of dissolved oxygen during denitrification when the BOD 5 load is low. These phenomena cause inhibitory effects and BOD 5 deficiency in the denitrification process. The results demonstrate the need for a more complex approach to designing and managing small wastewater treatment plants (WWTPs) provided with denitrification than those usually adopted for medium- and large-size plants.
Study on Aerobic Denitrification in BAF

DENG Kang,HUANG Shao-bin,HU Ting,

环境科学 , 2010,
Abstract: The compound inoculation was investigated, and the influences of COD/N ratio and dissolved oxygen on aerobic denitrification in biological aerated filter(BAF) were tested while treating nitrate wastewater from an iron factory. The results show that the efficiency of denitrification was improved, when the concentration of dissolved oxygen was increased from 1.5 mg/L to 4.2 mg/L.When dissolved oxygen value was 3.5 mg/L, the efficiency was the best, it was 95.4%; but the result was opposite when it were increased. When dissolved oxygen value was 8.0 mg/L; the efficiency was still 44.8%.it can be inferred that there were aerobic denitrifer, and oxygen was the electron accepter during aerobic denitrification. The efficiency of aerobic denitrification was improved. When COD /N were 6-7, it can meet the requirement for carbon source during aerobic denitrification, the removal rate of nitrate nitrogen and COD were up to 96%, 85% respectively. Almost no nitrite nitrogen accumulated.
Process control of simultaneous shortcut nitrification and denitrification in a Sequencing Batch Moving Bed Biofilm Reactor (SBMBBR)

环境科学学报 , 2008,
Abstract: Nitrosification and denitrification in an artificial domestic wastewater with low COD were studied in a sequencing batch moving bed biofilm reactor (SBMBBR). The results showed that the shortcut nitrification was influenced by anoxic time, COD, NH+4-N, pH and dissolved oxygen. When COD in the wastewater feed was 100 mg·L-1 and NH+4-N was 50 mg·L-1, a 99.7% nitrite accumulation ratio and 66.4% TN removal were reached by adjusting the DO and pH in the process, which meant that simultaneous shortcut nitrification and denitrification occurred in the system.
Analysis of dissolved oxygen & velocity for the Carrousel oxidation ditch in a wastewater treatment plant

Fan Long,Wang Zhiqiang,Wang Yingzhe,Chen Dafang,Luo Bin,Liu Yanchen,Shi Hanchang,

环境工程学报 , 2007,
Abstract: By experimenting in a wastewater treatment plant in Changsha, the distributions of dissolved oxygen & velocity at different locations in an oxidation ditch were obtained. The influences of aerators number, depth of oxidation ditch, as well as the ratio of oxidation ditch length to width were discussed. By analysis, it is found that the anaerobic region and aerobic region could be obtained simultaneously in one oxidation ditch. Then corresponding methods for the wastewater treatment plant are presented. All these provide evidence for the realization of simultaneous nitrification and denitrification in oxidation ditch in the future.
Oxygen-limited autotrophic nitrification and denitrification- A novel technology for biological nitrogen removal

ZHANG Dan,XU Hui,LI Xiangli,ZHANG Ying,CHEN Guanxiong,

应用生态学报 , 2003,
Abstract: Oxygen-limited autotrophic nitrification and denitrification (OLAND) is a biological nitrogen removal process coupled with partial nitrification and anaerobic ammonium oxidation. In our study, the nitrification was blocked at nitrite stage by controlling the dissolved oxygen concentration at 0.1-0.3 mg.L-1, and then, the denitrification proceeded, with the residual ammonium at the partial nitrification stage as electron donor. As a completely autotrophic nitrification-denitrification process, the OLAND was of many advantages (e.g., low energy consumption, high nitrogen removal rate and small footprint of system), and suitable in particular for treating low COD/NH4(+)-N ratio wastewater. It has become one of the most prosperous and practicable biological nitrogen removal technologies. The recent research of OLAND was reviewed, and its microbial mechanism as well as its applicable prospect was remarked in this paper.
Effects of COD/N ratio and DO concentration on simultaneous nitrification and denitrification in an airlift internal circulation membrane bioreactor

MENG Qingjuan,YANG Fenglin,LIU Lifen,MENG Fangang,

环境科学学报(英文版) , 2008,
Abstract: The effects of chemical oxygen demand and nitrogen(COD/N)ratio and dissolved oxygen concentration(DO)on simultaneous nitrification and denitrification(SND)were investigated using an airlift internal circulation membrane bioreactor(AIC-MBR)with synthetic wastewater.The results showed that the COD efficiencies were consistently greater than 90% regardless of changes in the COD/N ratio.At the COD/N ratio of 4.77 and 10.04,the system nitrogen removal efficiency became higher than 70%.However,the nitrogen rem...
Flow field and dissolved oxygen distributions in the outer channel of the Orbal oxidation ditch by monitor and CFD simulation
Xuesong Guo,Xin Zhou,Qiuwen Chen,Junxin Liu,
Xuesong Guo
,Xin Zhou,Qiuwen Chen,Junxin Liu

环境科学学报(英文版) , 2013,
Abstract: In the Orbal oxidation ditch, denitrification is primarily accomplished in the outer channel. However, the detailed characteristics of the flow field and dissolved oxygen (DO) distribution in the outer channel are not well understood. Therefore, in this study, the flow velocity and DO concentration in the outer channel of an Orbal oxidation ditch system in a wastewater treatment plant in Beijing (China) were monitored under actual operation conditions. The flow field and DO concentration distributions were analyzed by computed fluid dynamic modeling. In situ monitoring and modeling both showed that the flow velocity was heterogeneous in the outer channel. As a result, the DO was also heterogeneously distributed in the outer channel, with concentration gradients occurring along the flow direction as well as in the cross-section. This heterogeneous DO distribution created many anoxic and aerobic zones, which may have facilitated simultaneous nitrification-denitrification in the channel. These findings may provide supporting information for rational optimization of the performance of the Orbal oxidation ditch.
The potential of dairy wastewater for denitrification  [cached]
Tibela Landeka Dragi?evi?,Marijana Zano?ki Hren,Dijana Grgas,Igor Buzdum
Mljekarstvo , 2010,
Abstract: In this work the potential of dairy wastewater for denitrification process by means of a microbial culture of nitrificants and denitrificants was investigated. The aim of this work was to remove nitrate by using organic compounds from the dairy wastewater as an electron donors. The minimal ratio of COD/NO3-N of 10 (COD-chemical oxygen demand/NO3-N-nitrate nitrogen) was required to achieve complete reduction of NO3-N. The microbial culture of nitrificants and denitrificants, that was previously adapted on the dairy wastewater, carried out nitrate reduction with a different substrate utilization rate. The denitrification rate of 5.75 mg NO3-N/Lh was achieved at the beginning of denitrification when the microbial culture utilizes readily biodegradable COD. Further degradation occurred with the denitrification rate of 1.7 mg NO3-N/Lh.
The continuous dual of the sequence space lp(Dn ), (1 £ p £ ¥ , n N )
M. Imaninezhad and M. Miri
Abstract: The space lp(Dm ) consisting of all sequences whose m-th order differences are p-absolutely summable was recently studied by Altay. Following Altay, we have found the continuous dual of the spaces l1(Dn ) and lP(Dn ). We have also determined the norm of the operator Dn acting from l1 to itself and from l¥ to itself, and proved that Dn is a bounded linear operator on the space lp(Dn ).
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