Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Nitrogen removal and simultaneous nitrification and denitrification in a fluidized bed step-feed process

Bing Wang,Wei Wang,Hongjun Han,Hongbo Hu,Haifeng Zhuang,

环境科学学报(英文版) , 2012,
Abstract: 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 effluent 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.
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.
The Influence of Ecological Factors on Simultaneous Nitrification and Denitrification in MBR

Zou Lianpei,Liu Xudong,Wang Baozhen,Fan Yanzhen,

环境科学 , 2001,
Abstract: The influence of dissolved oxygen(DO), C/N and pH on simultaneous nitrification and denitrification in the membrane bioreactor was studied. The experimental results showed that only under condition that each ecological factor was maintained relative steady, simultaneous nitrification and denitrification might proceed smoothly. When DO, C/N and pH of feed water was 1mg/L, 30 and 7.2, the removal rate of COD, NH4+, and TN were 96%, 95% and 92% respectively.
Study on Affecting Factors of Simultaneous Nitrification and Denitrification in Moving-bed Biofilm System

WEI Hai-juan,ZHANG Yong-xiang,ZHANG Can,

环境科学 , 2009,
Abstract: The phenomenon of simultaneous nitrification and denitrification(SND) has taken place in moving-bed biofilm reactor(MBBR) steadily.The effect of C/N to denitrification effectiveness has been also studied in the experiment.The results of the treatment show that better denitrification efficiency could be obtained by increasing C/N ratio and the removal ratios of TN reached 92.9%.When C/N ratio is 12,the amplitude of TN removal ratio is not obvious.The effects of pH to ammonia nitrogen and TN removal ratio hav...
Factors affecting simultaneous nitrification and denitrification in a SBBR treating domestic wastewater

LI Jun,PENG Yongzhen,GU Guowei,WEI Su,

环境科学学报 , 2006,
Abstract: An aerobic sequencing batch biofilm reactor (SBBR) packed with Baoer rings was used to treat real domestic wastewater. The aim was to achieve simultaneous nitrification and denitrification. The SBBR is advantageous to create anoxic condition, and biofilm can absorb and store carbon for good nitrification and denitrification. A concentration of average oxygen range from 0.8 to 4.0 mg?L-1 was proved very efficient for nitrification and denitrification. Volumetric loads of TN were dropped dramatically and effluent TN concentration increased quickly when the concentration of average oxygen was more than 4.0 mg?L-1. The efficiency of simultaneous nitrification and denitrification increased with increasing of thickness of the biofilm. The influent concentration hardly affected the TN removal efficiency, but the effluent TN increased with increasing of influent concentration. It is suggested that a subsequence for denitrification is added or influent amount is decreased for requirement of effluent quality. At optimum operating parameters, the TN removal efficiency of 74%~82% could be achieved.
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...
Cultivation of aerobic granules for simultaneous nitrification and denitrification by seeding different inoculated sludge
WANG Fang,YANG Feng-lin,LIU Yi-hui,ZHANG Xing-wen,
,YANG Feng-lin,LIU Yi-hui,ZHANG Xing-wen

环境科学学报(英文版) , 2005,
Abstract: Cultivation of aerobic granules for simultaneous nitrification and denitrification in two sequencing batch airlift bioreactors was studied. Conventional activated floc and anaerobic granules served as main two inoculated sludge in the systems. Morphological variations of sludge in the reactors were observed. It was found that the cultivation of aerobic granules was closely associated with the kind of inoculated sludge. Round and regular aerobic granules were prevailed in both reactors, and the physical characteristics of the aerobic granules in terms of settling ability, specific gravity, and ratio of water containing were distinct when the inoculate sludge was different. Aerobic granules formed by seeding activated floc are more excellent in simultaneous nitrification and denitrification than that by aerobic granules formed from anaerobic granules. It was concluded that inoculated sludge plays a crucial role in the cultivation of aerobic granules for simultaneous nitrification and denitrification.
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.
Removal effect of organic pollutants during the course of treating landfill leachate with simultaneous nitrification and denitrification

Zhang Hongguo,Chen Diyun,Yan Jia,Zhou Shaoqi,

环境工程学报 , 2009,
Abstract: Removal effect of organic pollutants in the landfill leachate, which treated by simultaneous nitrification and denitrification, were analysed in the paper. It was demonstrated that well removal effect of COD, NH3-N, total nitrogen and organic matters could be reached in the sequencing batch reactor, corresponding to the average removal efficiencies of COD, NH3-N, total nitrogen being 82.34%, 99.82% and 65.31%, respectively. 53 species of organic matters had been detected by gas chromatograph-mass spectrometer (GC-MS) method. Among them, 29 species of organic compounds were completely removed, for example, butyl phthalate. 5 species of organic compounds were removed more than 90%, for example, ethylbenzene. Removal efficiencies of 8 species of organic compounds were obtained between 60% and 90%, for example, diisooctyl phthalate. Moreover, there were still 5 species of organic compounds that the removal efficiencies were below 60%, for example, 4-phenyl-pentanol. It indicated that there was part denitrification via nitrite in the system.
Simultaneous Nitrification and Denitrification of Membrane-Aerated Biofilm Reactor

HU Shao-wei,YANG Feng-lin,LIU Si-tong,GONG Zheng,

环境科学 , 2009,
Abstract: A carbon membrane-aerated biofilm reactor was developed to treat municipal wastewater, in which the carbon and nitrogen were removed simultaneously. The results showed that COD removal, NH+4-N removal and TN removal efficiency could reach 82.5%, 95.1% and 84.2%, respectively, under the conditions of intra-membrane pressure of 13.6 kPa, HRT of 14 h, influent COD and NH+4-N concentrations of 338 mg/L and 75 mg/L. However, in the last period during the operation of the reactor, the TN removal efficiency dramatically decreased because of the excessive growth of biomass on the nonwoven fiber, which also had serious negative effect on nitrification course. The microbiological community and spatial profiles were observed by fluorescence in situ hybridization and scanning electron microscopy. The anaerobic and anoxic bacteria were mainly located in the outer anaerobic region of the biofilm, while the aerobic ammonium oxidizing bacteria were mainly located in the inner aerobic region of the biofilm. The co-existing and coupling effect of aerobic nitrifying bacteria and anaerobic denitrifying bacteria provided the large biological potential for the simultaneous nitrification and denitrification in the carbon membrane-aerated biofilm reactor.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.