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Simultaneous nitrification and autotrophic denitrification in fluidized bed reactors using pyrite and elemental sulfur as electron donors 被引量:1
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作者 Maria F.Carboni Sonia Arriaga Piet N.L.Lens 《Water Science and Engineering》 EI CAS CSCD 2023年第2期143-153,共11页
In this study, simultaneous nitrification and autotrophic denitrification (SNAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was... In this study, simultaneous nitrification and autotrophic denitrification (SNAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was evaluated at different ammonium (12-40 mg/L of NH4+-N), nitrate (35-45 mg/L of NO3--N), and dissolved oxygen (DO) (0.1-1.5 mg/L) concentrations, with a hydraulic retention time of 12 h. The pyrite reactor supported the SNAD process with a maximum nitrogen removal efficiency of 139.5 mg/(L·d) when the DO concentration was in the range of 0.8-1.5 mg/L. This range, however, limited the denitrification efficiency of the reactor, which decreased from 90.0% ± 5.3% in phases II-V to 67.9% ± 7.2% in phases VI and VII. Sulfate precipitated as iron sulfate (FeSO4/Fe2(SO4)3) and sodium sulfate (Na2SO4) minerals during the experiment. The sulfur reactor did not respond well to nitrification with a low and unstable ammonium removal efficiency, while denitrification occurred with a nitrate removal efficiency of 97.8%. In the pyrite system, the nitrifying bacterium Nitrosomonas sp. was present, and its relative abundance increased from 0.1% to 1.1%, while the autotrophic denitrifying genera Terrimonas, Ferruginibacter, and Denitratimonas dominated the community. Thiobacillus, Sulfurovum, and Trichlorobacter were the most abundant genera in the sulfur reactor during the entire experiment. 展开更多
关键词 PYRITE Elemental sulfur Simultaneous nitrification and denitrification Nitrogen removal 16S rRNA
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Nitrogen Release Kinetics and Nitrification-Denitrification on Surface Sediments under Aerating Disturbance Condition 被引量:5
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作者 林佩祯 余光伟 +3 位作者 种云霄 肖航 许诺 黄梅 《Agricultural Science & Technology》 CAS 2012年第8期1733-1737,共5页
[Objective] This study aimed to investigate the nitrogen release kinetics and nitrification-denitrification on surface sediments under aerating disturbance condition, with the purpose to solve the sediment nitrogen re... [Objective] This study aimed to investigate the nitrogen release kinetics and nitrification-denitrification on surface sediments under aerating disturbance condition, with the purpose to solve the sediment nitrogen release and secondary pollution problems. [Method] The effect of in situ sediments aeration on the release of nitrogen pollutants was investigated, and the nitrogen release kinetics parameters were analyzed. The process of nitrification and denitrification under sediments aeration condition was investigated in laboratory. [Result] The nitrogen released from sediments was enhanced by aeration disturbance. The concentration of NH4+-N and TN reached the maximum value in 30 min, and release rates were proportional to the disturbance strength. In this study, with the distance of aerator to the sediments surface of 0, 1, 2 and 3 cm, the suspended sediments concentrations were 3.52, 3.41, 3.26 and 3.01 g/L, respectively. Maximum release concentration of NH4+-N and TN were 14.3, 13.8, 13.2, 12.2 mg/L and 33.21, 30.98, 29.83, 27.30 mg/L, respec- tively. In addition, both NH4+-N and TN release kinetics could be described by Double Constant Equation as InC=A+Blnt. Nitrification reaction occurred and was promoted by continued aerating to sediments.The concentration of NH4+-N dropped down from 12.4 mg/L to 0.2 mg/L in 8 d, with the concentration of NO3--N increased to the maximum value of 10.8 mg/L. In addition, concentration of NO3--N and TN decreased from 10.8 mg/L and 37.4 mg/L to 0.36 mg/L and 23.2 mg/L after the stop of aeration for 12 d, indicating the occurrence of denitdfication reaction. Therefore, sediment aeration could accelerate nitrogen release and nitrification reaction, and with intermittent aeration, nitrogen could be removed from sediments in-situ by nitrification and denitrification. [Conclusion] The results provided technical reference for the in situ sediment remediation for the black-odor rivers in cities. 展开更多
关键词 In situ sediments aeration Nitrogen release nitrification and denitrification Nitrogen removal Kinetics
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Simultaneous nitrification and denitrification in step feeding biological nitrogen removal process 被引量:19
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作者 ZHU Gui-bing PENG Yong-zhen +2 位作者 WU Shu-yun WANG Shu-ying XU Shi-wei 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第9期1043-1048,共6页
The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates. Biological occurrence... The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates. Biological occurrence of simultaneous nitrification and denitrification was verified in the aspect of nitrogen mass balance and alkalinity. The experimental results also showed that there was a distinct linear relationship between simultaneous nitrification and denitrification and DO concentration under the conditions of low and high aeration flow rate. In each experimental run the floc sizes of activated sludge were also measured and the results showed that simultaneous nitrification and denitrification could occur with very small size of floc. 展开更多
关键词 biological nitrogen removal dissolved oxygen floc size simultaneous nitrification and denitrification step feeding process
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Nitrogen Removal by Simultaneous Nitrification and Denitrification via Nitrite in a Sequence Hybrid Biological Reactor 被引量:12
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作者 王建龙 彭永臻 +1 位作者 王淑莹 高永青 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第5期778-784,共7页
Sequence hybrid biological reactor (SHBR) was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification (SND) via nitrite. S... Sequence hybrid biological reactor (SHBR) was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification (SND) via nitrite. SND via nitrite was achieved in SHBR by controlling demand oxygen (DO) concentration. There was a programmed decrease of the DO from 2.50 mg·L^-1 to 0.30 mg·L^-1, and the average nitrite accumulation rate (NAR) was increased from 16.5% to 95.5% in 3 weeks. Subsequently, further increase in DO concentration to 1.50 mg·L^-1 did not destroy the partial nitrification to nitrite. The results showed that limited air flow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate. Nitrogen removal efficiency was increased with the increase in NAR, that is, NAR was increased from 60% to 90%, and total nitrogen removal efficiency was increased from 68% to 85%. The SHBR could tolerate high organic loading rate (OLR), COD and ammonia-nitrogen removal efficiency were greater than 92% and 93.5%, respectively,, and it even operated under low DO concentration (0.5 mg·L^-1) and maintained high OLR (4.0 kg COD·m^-3·d^-1). The presence of biofilm positively affected the activated sludge settling capability, and sludge volume index (SVI) of activated sludge in SHBR never hit more than 90 ml·L^-1 throughout the experiments. 展开更多
关键词 nitrogen removal simultaneous nitrification and denitrification nitrite accumulation demand oxygen PH
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Effects of COD/N ratio and DO concentration on simultaneous nitrification and denitrification in an airlift internal circulation membrane bioreactor 被引量:18
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作者 Meng Qingjuan Yang Fenglin +1 位作者 Liu Lifen Meng Fangang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第8期933-939,共7页
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 membra... 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 remova... 展开更多
关键词 simultaneous nitrification and denitrification(SND) chemical oxygen demand and nitrogen(COD/N)ratio dissolved oxygen(DO)concentration
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Simultaneous heterotrophic nitrification and aerobic denitrification at high initial phenol concentration by isolated bacterium Diaphorobacter sp. PD-7 被引量:30
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作者 Qilong Ge Xiuping Yue Guoying Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第5期835-841,共7页
A strain capable of phenol degradation, hetemtrophic nitrification and aerobic denitrification was isolated from activated sludge of coking-plant wastewater ponds under aerobic condition. Based on its morphology, phys... A strain capable of phenol degradation, hetemtrophic nitrification and aerobic denitrification was isolated from activated sludge of coking-plant wastewater ponds under aerobic condition. Based on its morphology, physiology, biochemical analysis and phylogenetic characteristics, the isolate was identified as Diaphorobacter sp. PD-7. Biodegradation tests of phenol showed that the maximum phenol degradation occurred at the late phase of exponential growth stages, with 1400 mg·L^-1 phenol completely degraded within 85 h. Diaphorobacter sp. PD-7 accumulated a vast quantity of phenol hydroxylase in this physiological phase, ensuring that the cells quickly utilize phenol as a sole carbon and energy source. The kinetic behavior ofDiaphorobacter sp. PD-7 in batch cultures was investigated over a wide range of initial phenol concentrations (0-1400mg·L^-1) by using the Haldane model, which adequately describes the dynamic behavior of phenol biodegradation by strain Diaphombacter sp. PD-7. At initial phenol concentration of 1400mg· L^-l, batch experiments (0.25 L flask) of nitrogen removal under aerobic condition gave almost entirely removal of 120.69mg· L^- 1 ammonium nitrogen within 75 h, while nitrate nitrogen removal reached 91% within 65 h. Moreover, hydroxylamine oxidase, periplasmic nitrate reductase and nitrite reductase were successfully expressed in the isolate. 展开更多
关键词 Diaphorobacter sp.Phenol biodegradation Kinetics Heterotrophic nitrification Aerobic denitrification Enzyme activity
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Performance of simultaneous nitrification and denitrification in lateral flow biological aerated filter 被引量:1
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作者 龙腾锐 《Journal of Chongqing University》 CAS 2006年第4期223-228,共6页
A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has ... A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has the function of nitrification and removing organic substrate. In this study, we focused on the denitrification performance of LBAF and its possible mechanism under thorough aeration. We identified the existence of simultaneous nitrification and denitrification (SND) by analyzing nitrogenous compounds along the flow path of LBAF and supportive microbial microscopy, and studied the effects of air/water ratio and hydraulic loading on the performance of nitrogen removal and on SND in LBAF to find out the optimal operation condition. It is found that for saving operation cost, aeration can be reduced to some degree that allows desirable removal efficiency of pollutants, and the optimal air/water ratio is 10:1. Hydraulic loading less than 0.43 m h?1 hardly affects the nitrification and denitrification performance; whereas higher hydraulic loading is unfavorable to both nitrification and denitrification, far more unfavorable to denitrification than to nitrification. 展开更多
关键词 lateral flow biological aerated filter simultaneous nitrification and denitrification air/water ratio hydraulic loading
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Control strategy of simultaneous nitrification and denitrification in SBR system
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作者 LOU Ju-qing GUO Mao-xin SHEN Xiao-ming 《Journal of Environmental Science and Engineering》 2008年第5期21-26,共6页
The influence of main process parameters on simultaneous nitrification and denitrification (SND) in a sequencing batch reactor (SBR) were investigated while treating actual municipal sewage. The influent average c... The influence of main process parameters on simultaneous nitrification and denitrification (SND) in a sequencing batch reactor (SBR) were investigated while treating actual municipal sewage. The influent average concentration of CODcr and total nitrogen was 350mg-L-l and 35mg.L-l. The experiment indicated the following four operation control strategies: (1) When operation cycle was 6 hours, oxidation of organic pollutants and simultaneous nitrification and denitrification could well completed in the SBR reactor; (2) TN removal rate could be increased significantly, 40% higher than traditional SBR processes when idle period was set between influent and aeration; (3) The time of idle period could affect simultaneous nitrification and denitrification and the best time is 30 minutes; (4) Increase of sludge organic load may improve TN removal efficiency, but NH3-N removal efficiency declines. 展开更多
关键词 SBR simultaneous nitrification and denitrification IDLE CYCLE sludge load
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Effects of Aeration Rates and Patterns on Shortcut Nitrification and Denitrification
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作者 Ali Ibrah Landi Jun Lu 《Journal of Environmental Protection》 CAS 2022年第9期640-656,共17页
The effects of aeration rates and aeration patterns on the oxidation of ammonia-nitrogen into nitrite were investigated. The influent high ammonia-nitrogen synthetic wastewater resembled to those of the catalytic proc... The effects of aeration rates and aeration patterns on the oxidation of ammonia-nitrogen into nitrite were investigated. The influent high ammonia-nitrogen synthetic wastewater resembled to those of the catalytic process of the petrochemical refinery. The method involved the biological shortcut nitrification and denitrification lab-scale’s sequencing batch reactor (SBR) process based on intermittent aerations and aeration patterns. All the operations were carried out in a 20 L working volume SBR bioreactor, and the influent synthetic wastewater’s concentration was always 1000 mg/L ammonia-nitrogen NH<sub>4</sub>-N concentration at a C/N (carbon/nitrogen) ratio of 2.5:1. Effective shortcut nitrification to nitrite was registered at 1.1 mg-O<sub>2</sub>/L (i.e. 9 L-air/min) with 99.1% nitrification efficiency, 99.0% nitritation rate and 2.6 mg-NO<sub>3</sub>-</sup>-N/L nitrate concentration. The best results with 99.3% nitrification efficiency were recorded when operating at 1.4 mg-O<sub>2</sub>/L (i.e. 12 L-air/min). According to these experiments, it results that the nitrite accumulation rate was related to aeration rate and cycle’s duration. However, at 1.7 mg-O<sub>2</sub>/L (i.e. 15 L-air/min), the system was limited by an increase in nitrate concentration with more than 5 mg/L which could be a point of reverse to conventional nitrification. The best total nitrogen (TN) removal was about 71.5%. 展开更多
关键词 Wastewater Treatment SBR Partial nitrification/denitrification Intermittent Aeration Aeration Rate Aeration Pattern Total Nitrogen (TN) Removal
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Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system 被引量:35
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作者 PENG Yongzhen HOU Hongxun +2 位作者 WANG Shuying CUI Youwei Zhiguo Yuan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第4期398-403,共6页
To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was... To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch (OD), where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification (SND) rate (rSND) was put forward to quantify SND. The results indicate that: (1) high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen (TN) and total phosphate (TP) removal rates were 80% and 85%, respectively; (2) when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; (3) the natural logarithm of the ratio of NOx to NH4^+ in the effluent had a linear correlation to oxidation-reduction potential (ORP); (4) when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; (5) denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified. 展开更多
关键词 oxidation ditch biological nitrogen removal biological phosphorus removal simultaneous nitrification and denitrification (SND) pilot scale municipal wastewater
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Nitrogen removal and simultaneous nitrification and denitrification in a fluidized bed step-feed process 被引量:23
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作者 BingWang Wei Wang +2 位作者 Hongjun Han Hongbo Hu Haifeng Zhuang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第2期303-308,共6页
For urban wastewater treatment,we conducted a novel four-stage step-feed wastewater treatment system combined with a fluidized bed laboratory experiment to investigate chemical oxygen demand(COD),NH4+-N,and total n... For urban wastewater treatment,we conducted a novel four-stage step-feed wastewater treatment system combined with a fluidized bed laboratory experiment to investigate chemical oxygen demand(COD),NH4+-N,and total nitrogen(TN) removal performance.The removal rates of COD,NH4+-N and TN were 88.2%,95.7%,and 86.4% with e?uent concentrations of COD,NH4+-N and TN less than 50,8,and 10 mg/L,respectively.Biomass and bacterial activities were also measured,with results showing more nitrobacteria in the activated sludge than in the biofilm;however,bacterial activity of the biofilm biomass and the activated sludge were similar.Nitrogen concentrations during the process were also detected,with simultaneous nitrification and denitrification found to be obvious. 展开更多
关键词 denitrification fluidized bed STEP-FEED simultaneous nitrification and denitrification
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Novel strategy of nitrogen removal from domestic wastewater using pilot Orbal oxidation ditch 被引量:11
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作者 GAO Shou-you PENG Yong-zhen +1 位作者 WANG Shu-ying YAN Jun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第5期833-839,共7页
A pilot-scale Orbed oxidation ditch was operated for 17 months to optimize nitrogen removal from domestic wastewater of average COD to total nitrogen ratio of 2.7, with particular concern about the roles of dissolved ... A pilot-scale Orbed oxidation ditch was operated for 17 months to optimize nitrogen removal from domestic wastewater of average COD to total nitrogen ratio of 2.7, with particular concern about the roles of dissolved oxygen (DO), mixed liquor suspended solids (MLSS) and return activated sludge (RAS) recycle ratio. Remarkable simultaneous nitrification and denitrification (SND) was observed and mean total nitrogen (TN) removal efficiency up to 72.1% was steadily achieved, at DO concentration in the out, middle and inner channel of 0.1, 0.4 and 0.7 mg/L, respectively, with an average M LSS of 5.5 g/L and RAS recycle ratio of 150%. Although the out channel took the major role in TN removal, the role of middle channel should never be ignored. The denitrification potential could be fully developed under low DO, high MLSS with adequate RAS ratio. The sludge settleability was amazingly improved under low DO operation mode, and some explanations were tried. In addition, a scries of simplified batch tests were done to determine whether novel microorganisms could make substantial contribution to the performance of nitrogen removal. The results indicated that the SND observed in this Orbal oxidation ditch was more likely a physical phenomenon. 展开更多
关键词 nitrogen removal simultaneous nitrification and denitrification low DO MLSS novel bacterial
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Community analysis of ammonia and nitrite oxidizers in start-up of aerobic granular sludge reactor 被引量:13
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作者 WANG Feng XIA Si-qing +2 位作者 LIU Yi CHEN Xue-song ZHANG Jun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第8期996-1002,共7页
A lab-scale sequencing batch reactor (SBR) was set-up and the aerobic granular sludge was successfully incubated using anaerobic granular sludge as seed sludge. Nitrogen was partially removed by simultaneous nitrifi... A lab-scale sequencing batch reactor (SBR) was set-up and the aerobic granular sludge was successfully incubated using anaerobic granular sludge as seed sludge. Nitrogen was partially removed by simultaneous nitrification and denitrification (SND) via nitrite with free ammonia (FA) of about 10 mg/L. The denaturing gradient gel electrophoresis (DGGE) method was used to investigate community structure of α-Proteobacteria, β-Proteobacteria, ammonia oxidizing bacteria (AOB), and Nitrospira populations during start-up. The population sizes of bacteria, AOB and Nitrospira were examined using real-time PCR method. The analysis of community structure and Shannon index showed that stable structure of AOB population was obtained at day 35, while the communities of α- Proteobacteria, β-Proteobacteria, and Nitrospira became stable after day 45. At stable stage, the average cell densities were 1.1× 10^12, 2.2×10^10 and 1.0×10^10 cells/L for bacteria, AOB and Nitrospira, respectively. The relationship between characteristics of nitrifying bacteria community and nitrogenous substrate utilization constant was discussed by calculating Pearson correlation. Certain correlation seemed to exist between population size, biodiversity, and degradation constant. And the influence of population size might be greater than that of biodiversity. 展开更多
关键词 aerobic granular sludge simultaneous nitrification and denitrification nitrite accumulation denaturing gradient gel electrophoresis real-time PCR
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Biological nitrogen removal with enhanced phosphate uptake in (AO)2SBR using single sludge system 被引量:11
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作者 JIANGYi-feng WANGLin +2 位作者 WANGBao-zhen HESheng-bing LIUShuo 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第6期1037-1040,共4页
Simultaneous biological phosphorus and nitrogen removal with enhanced anoxic phosphate uptake via nitrite was investigated in an anaerobic-aerobic-anoxic-aerobic sequencing batch reactor((AO)2 SBR). The system showed ... Simultaneous biological phosphorus and nitrogen removal with enhanced anoxic phosphate uptake via nitrite was investigated in an anaerobic-aerobic-anoxic-aerobic sequencing batch reactor((AO)2 SBR). The system showed stable phosphorus and nitrogen removal performance, and average removals for COD, TN and TP were 90%, 91% and 96%, respectively. The conditions of pH 7.5—8.0 and temperature 32℃ were found detrimental to nitrite oxidation bacteria but favorable to ammonia oxidizers, and the corresponding specific oxygen uptake rates(SOUR) for phase 1 and 2 of nitrification process were 0.7 and 15 mgO 2/(gVSS·h) in respect, which led to the nitrite accumulation in aerobic phase of(AO)2 SBR. Respiratory tests showed that 40 mgNO 2-N/L did not deteriorate the sludge activity drastically, and it implied that exposure of sludge to nitrite periodically enabled the biomass to have more tolerance capacity to resist the restraining effects from nitrite. In addition, batch tests were carried out and verified that denitrifying phosphorus accumulation organisms(DPAOs) could be enriched in a single sludge system coexisting with nitrifiers by introducing an anoxic phase in an anaerobic-aerobic SBR, and the ratio of the anoxic phosphate uptake capacity to aerobic phosphate uptake capacity was 45%. It was also found that nitrite(up to 20 mgNO 2-N/L) was not inhibitory to anoxic phosphate uptake and could serve as an electron acceptor like nitrate, but presented poorer efficiency compared with nitrate. 展开更多
关键词 denitrifying phosphorus accumulation organisms(DPAOs) shortcut nitrification and denitrification anoxic phosphate uptake sequencing batch reactor(SBR) NITRITE electron acceptor
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Isolation and characterization of heterotrophic nitrifying bacteria in MBR 被引量:7
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作者 LINYan HEYi-liang +3 位作者 KONGHai-nan LIUBin-bin LIYan INAMONYuhei 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第4期589-592,共4页
The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. Continuous tests via a membrane bioreactor (MBR) were operated under the controlled co... The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. Continuous tests via a membrane bioreactor (MBR) were operated under the controlled conditions to proliferate the nitrifiers. Heterotrophic nitrifying bacteria were isolated from the system in which the efficiency of total nitrogen(TN) removal was up to 80%. Since no autotrophic ammonium and nitrite oxidizers could be detected by fluorescence in situ hybridization(FISH), oxidized-N production was unlikely to be catalyzed by autotrophic nitrifiers during the heterotrophic nitrifiers' isolation in this study. The batch test results indicate that the isolated heterotrophic bacteria were able to nitrify. After 3 weeks incubation, the efficiencies of the COD removal by the three isolated bacterial strains B1, B2, and B3 were 52 6%, 71 7%, and 77 7%, respectively. The efficiencies of the TN removal by B1, B2, and B3 were 35 6%, 61 2% and 68 7%, respectively. 展开更多
关键词 membrane bioreactor(MBR) simultaneous nitrification and denitrification(SND) heterotrophic nitrification aerobic denitrification
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Variation of biological and hydrological parameters and nitrogen removal optimization of modified Carrousel oxidation ditch process 被引量:6
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作者 张智 李柏林 +2 位作者 相欣奕 张驰 柴华 《Journal of Central South University》 SCIE EI CAS 2012年第3期842-849,共8页
To enhance the nitrogen removal,a systemic monitoring of the biological and hydrological parameters of Carrousel oxidation ditch in Chongqing Jingkou Wastewater Treatment Plant was carried out to study the feasibility... To enhance the nitrogen removal,a systemic monitoring of the biological and hydrological parameters of Carrousel oxidation ditch in Chongqing Jingkou Wastewater Treatment Plant was carried out to study the feasibility of simultaneous nitrification and denitrification(SND).The variation and distribution of parameters such as flow velocity,concentration of dissolved oxygen(DO) and mixed liquor suspended solids(MLSS) in oxidation ditch were monitored and analyzed,which were major control factors for SND.The results showed that,the dimensional distribution of flow velocity,DO and MLSS were affected significantly by the operation condition of the aeration wheels.With all the four aeration wheels being in operation,DO and flow velocity were higher and the mixing of MLSS was sufficient.With three aeration wheels being in operation,the flow velocity in most of the bottom areas was enough to meet the basic requirements of no deposition,and the anaerobic region and aerobic region could exist simultaneously in one oxidation ditch,which was helpful to the process of SND.According to spatial distribution characteristics of the flow velocity,DO and soluble components under optimized condition,different functional zones of biochemical reaction in the Carrousel oxidation ditch system were defined,which might contribute to the optimization control and SND of Carrousel oxidation ditch. 展开更多
关键词 Carrousel oxidation ditch flow velocity dissolved oxygen (DO) mixed liquor suspended solid (MLSS) simultaneous nitrification and denitrification (SND)
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Factors affecting simultaneous nitrification and denitrification in an SBBR treating domestic wastewater 被引量:5
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作者 LI Jun PENG Yongzhen +1 位作者 GU Guowei WEI Su 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2007年第2期246-250,共5页
An aerobic sequencing batch biofilm reactor(SBBR)packed with Bauer rings was used to treat real domestic wastewater for simultaneous nitrification and deni-trification.The SBBR is advantageous for creating an anoxic c... An aerobic sequencing batch biofilm reactor(SBBR)packed with Bauer rings was used to treat real domestic wastewater for simultaneous nitrification and deni-trification.The SBBR is advantageous for creating an anoxic condition,and the biofilm can absorb and store carbon for good nitrification and denitrification.An average concentra-tion of oxygen ranging from 0.8 to 4.0 mg/L was proved very efficient for nitrification and denitrification.Volumetric loads of TN dropped dramatically and effluent TN concentra-tion increased quickly when the concentration of average dissolved oxygen was more than 4.0 mg/L.The efficiency of simultaneous nitrification and denitrification(SND)increased with increasing thickness of the biofilm.The influent concen-tration hardly affected the TN removal efficiency,but the effluent TN increased with increasing influent concentration.It is suggested that a subsequence for denitrification be added or influent amount be decreased to meet effluent quality requirements.At optimum operating parameters,the TN removal efficiency of 74%-82%could be achieved. 展开更多
关键词 sequencing batch biofilm reactor(SBBR) simultaneous nitrification and denitrification dissolved oxygen BIOFILM influent concentration
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A New Approach for Removal of Nitrogen Oxides from Synthetic Gas-streams under High Concentration of Oxygen in Biofilters 被引量:3
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作者 ShaoBinHUANG JuGuangZHANG HePingHU YueSITU 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第4期505-508,共4页
The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that ... The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that more than 85% of nitric oxide was removed from synthetic combustion gas-streams which contained 20% oxygen and 350 μL/L NO, with a residence time of 60 seconds. In the process, it was found that the existing of oxygen showed no evident negative effect on the efficiency of nitrogen removal. 展开更多
关键词 BIOFILTER nitrogen oxides nitrification denitrification aerobic.
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Simultaneous nitrification and denitrification in activated sludge system under low oxygen concentration 被引量:4
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作者 ZHANG Peng ZHOU Qi 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2007年第1期49-52,共4页
Simultaneous nitrification and denitrification(SND),which is more economical compared with the tradi-tional method for nitrogen removal,is studied in this paper.In order to find the suitable conditions of this process... Simultaneous nitrification and denitrification(SND),which is more economical compared with the tradi-tional method for nitrogen removal,is studied in this paper.In order to find the suitable conditions of this process,a mixed flow activated sludge system under low oxygen concentration is investigated,and some key control parameters are exam-ined for nitrogen removal from synthetic wastewater.The results show that SND is accessible when oxygen concentra-tion is 0.3-0.8 mg/L.The nitrogen removal rate can be obtained up to 66.7%with solids retention time(SRT)of 45 d,C/N value of 10,and F/M ratio of 0.1 g COD/(g MLSS·d).Theoretical analysis indicates that SND is a physical phenomenon and governed by oxygen diffusion in flocs. 展开更多
关键词 low oxygen concentration simultaneous nitrification and denitrification(SND) aerobic nitrification microenvironment theory
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Minimizing N_20 fluxes from full-scale municipal solid waste landfill with properly selected cover soil 被引量:3
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作者 ZHANG Houhu HE Pinjing +2 位作者 SHAO Liming QU Xian LEE Duujong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第2期189-194,共6页
Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use ... Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux. 展开更多
关键词 municipal solid waste landfill N2O flux cover soil LEACHATE nitrification/denitrification environmental factors
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