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Simultaneous nitrification and denitrification in activated sludge system under low oxygen concentration

ZHANG Peng, ZHOU Qi

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 49-52 doi: 10.1007/s11783-007-0009-1

摘要: Simultaneous nitrification and denitrification (SND), which is more economical compared with the traditional 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 examined for nitrogen removal from synthetic wastewater. The results show that SND is accessible when oxygen concentration 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.

关键词: synthetic wastewater     accessible     Simultaneous nitrification     MLSS·d     diffusion    

Factors affecting simultaneous nitrification and denitrification in an SBBR treating domestic wastewater

LI Jun, GU Guowei, PENG Yongzhen, WEI Su

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 246-250 doi: 10.1007/s11783-007-0042-0

摘要: An aerobic sequencing batch biofilm reactor (SBBR) packed with Bauer rings was used to treat real domestic wastewater for simultaneous nitrification and denitrification. The SBBR is advantageous for creating an anoxic condition, and the biofilm can absorb and store carbon for good nitrification and denitrification. An average concentration 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 concentration 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 concentration 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.

Preparation and characterization of a novel microorganism embedding material for simultaneous nitrification

Ming Zeng, Ping Li, Nan Wu, Xiaofang Li, Chang Wang

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0961-3

摘要: A novel microorganism embedding material was prepared to enhance the biological nitrogen removal through simultaneous nitrification and denitrification. Polyvinyl alcohol (PVA), sodium alginate (SA) and cyclodextrin (CD) were used to compose gel bead with embedded activated sludge. The effects of temperature, CD addition and concentrations of PVA and SA on nitrogen removal were evaluated. Results show that the gel bead with CD addition at 30°C contributed to the highest nitrogen removal efficiency and nitrogen removal rate of 85.4% and 2.08 mg·(L·h)?1, respectively. Meanwhile, negligible NO3? and NO2? were observed, proving the occurrence of simultaneous nitrification and denitrification. The High-Throughput Sequencing confirms that the microbial community mainly contained Comamonadaceae in the proportion of 61.3%. Overall, CD increased gel bead’s porosity and resulted in the high specific endogenous respiration rate and high nitrogen removal efficiency, which is a favorable additional agent to the traditional embedding material.

关键词: Immobilization technology     Nitrogen removal     Cyclodextrin     Microbial community     Wastewater treatment    

Practical consideration for design and optimization of the step feed process

Shijian GE, Yongzhen PENG, Congcong LU, Shuying WANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 135-142 doi: 10.1007/s11783-012-0454-3

摘要: Based on the anoxic/oxic (A/O) step feed process, a modified University of Cape Town (UCT) step feed process was developed by adding an anaerobic zone and adjusting sludge return pipeline. Performance evaluation of these two types of processes was investigated by optimizing operational parameters, such as the anaerobic/anoxic/oxic volumes, internal recycle ratios, and sludge retention times, for removal of chemical oxygen demanding (COD), nitrogen, and phosphorus. Results showed high removal efficiencies of COD of (85.0±1.7)%, ammonium of (99.7±0.2)%, total nitrogen (TN) of (85.5±1.7)%, phosphorus of (95.1±3.3)%, as well as excellent sludge settleability with average sludge volume index of (83.7±9.5) L·mg in the modified UCT process. Moreover, (61.5±6.0)% of influent COD was efficiently involved in denitrification or phosphorus release process. As much as 35.3% of TN was eliminated through simultaneous nitrification and denitrification process in aerobic zones. In addition, the presence of denitrifying phosphorus accumulating organisms (DNPAOs), accounting for approximately 39.2% of PAOs, was also greatly beneficial to the nitrogen and phosphorus removal. Consequently, the modified UCT step feed process was more attractive for the wastewater treatment plant, because it had extremely competitive advantages such as higher nutrient removal efficiencies, lower energy and dosages consumption, excellent settling sludge and operational assurance.

关键词: step feed     anoxic/oxic (A/O)     University of Cape Town (UCT)     simultaneous nitrification and denitrification (SND)     denitrifying phosphorus removal     biological nutrient removal (BNR)    

Control of sludge settleability and nitrogen removal under low dissolved oxygen condition

Zhaoxu PENG, Yongzhen PENG, Zhenbo YU, Xuliang LIU, Xiaoling LI, Randeng WANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第6期   页码 884-891 doi: 10.1007/s11783-012-0408-9

摘要: Low dissolved oxygen (DO) is an energy-saving condition in activated sludge process. To investigate the possible application of limited filamentous bulking (LFB) in sequencing batch reactor (SBR), two lab-scale SBRs were used to treat synthetic domestic wastewater and real municipal wastewater, respectively. The results showed that prolonging low DO aeration duration and setting pre-anoxic (anaerobic) phase were effective strategies to induce and inhibit filamentous sludge bulking, respectively. According to the sludge settleability, LFB could be maintained steadily by adjusting operation patterns. Filamentous bacteria content and sludge volume index (SVI) were likely correlated. SVI fluctuated dramatically within a few cycles when around 200 mL·g , where altering operation pattern could change sludge settleability in spite of the unstable status of activated sludge system. Energy consumption by aeration reduced under low DO LFB condition, whereas the nitrification performance deteriorated. However, short-cut nitrification and simultaneous nitrification denitrification (SND) were prone to take place under such conditions. When the cycle time kept constant, the anoxic (anaerobic) to aerobic time ratio was determining factor to the SND efficiency. Similarity keeping aerobic time as constant, the variation trends of SND efficiency and specific SND rate were uniform. SBR is a promising reactor to apply the LFB process in practice.

关键词: limited filamentous bulking     sequencing batch reactor     sludge settleability     sludge volume index     simultaneous nitrification denitrification    

Enhanced nitrogen removal and microbial analysis in partially saturated constructed wetland for treating anaerobically digested swine wastewater

Zhenfeng Han, Ying Miao, Jing Dong, Zhiqiang Shen, Yuexi Zhou, Shan Liu, Chunping Yang

《环境科学与工程前沿(英文)》 2019年 第13卷 第4期 doi: 10.1007/s11783-019-1133-4

摘要:

Anaerobically digested swine wastewater was treated by a novel constructed wetland.

Tidal operation was better for total nitrogen removal than intermittent flow.

Mechanism of nitrogen removal by biozeolite-based constructed wetland was discussed.

Simultaneous nitrification and denitrification were determined in zeolite layer.

关键词: Constructed wetland     Decentralized swine wastewater     Biozeolite     Simultaneous nitrification and denitrification     Nitrogen removal pathway    

Methanation and chemolitrophic nitrogen removal by an anaerobic membrane bioreactor coupled partial nitrification

《环境科学与工程前沿(英文)》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1668-2

摘要:

● Efficient carbon methanation and nitrogen removal was achieved in AnMBR-PN/A system.

关键词: Anaerobic membrane bioreactor     Partial nitrification/Anammox     Carbon separation     Chemolitrophic nitrogen removal    

A heterotrophic nitrification-aerobic denitrification bacterium TJPU05 suitable for nitrogen removal

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1503-6

摘要:

H. venusta TJPU05 showed excellent HN-AD ability at high salinity.

关键词: Salt-tolerant bacteria     H. venusta TJPU05     Heterotrophic nitrification and aerobic denitrification     High-salinity wastewater    

ROOT EXUDATES FROM CANOLA EXHIBIT BIOLOGICAL NITRIFICATION INHIBITION AND ARE EFFECTIVE IN INHIBITING

《农业科学与工程前沿(英文)》 2022年 第9卷 第2期   页码 177-186 doi: 10.15302/J-FASE-2021421

摘要:

A range of plant species produce root exudates that inhibit ammonia-oxidizing microorganisms. This biological nitrification inhibition (BNI) capacity can decrease N loss and increase N uptake from the rhizosphere. This study sought evidence for the existence and magnitude of BNI capacity in canola ( Brassica napus). Seedlings of three canola cultivars, Brachiaria humidicola(BNI positive) and wheat ( Triticum aestivum) were grown in a hydroponic system. Root exudates were collected and their inhibition of the ammonia oxidizing bacterium, Nitrosospira multiformis, was tested. Subsequent pot experiments were used to test the inhibition of native nitrifying communities in soil. Root exudates from canola significantly reduced nitrification rates of both N. multiformis cultures and native soil microbial communities. The level of nitrification inhibition across the three cultivars was similar to the well-studied high-BNI species B. humidicola. BNI capacity of canola may have implications for the N dynamics in farming systems and the N uptake efficiency of crops in rotational farming systems. By reducing nitrification rates canola crops may decrease N losses, increase plant N uptake and encourage microbial N immobilization and subsequently increase the pool of organic N that is available for mineralization during the following cereal crops.

关键词: ammonia oxidizing microorganisms / biological nitrification inhibition / farming rotations / nitrogen cycling / nitrogen use efficiency    

Improvement of nitrification efficiency by bioaugmentation in sequencing batch reactors at low temperature

Di CUI,Ang LI,Tian QIU,Rui CAI,Changlong PANG,Jihua WANG,Jixian YANG,Fang MA,Nanqi REN

《环境科学与工程前沿(英文)》 2014年 第8卷 第6期   页码 937-944 doi: 10.1007/s11783-014-0668-7

摘要: Bioaugmentation is an effective method of treating municipal wastewater with high ammonia concentration in sequencing batch reactors (SBRs) at low temperature (10°C). The cold-adapted ammonia- and nitrite- oxidizing bacteria were enriched and inoculated, respectively, in the bioaugmentation systems. In synthetic wastewater treatment systems, the average -N removal efficiency in the bioaugmented system (85%) was much higher than that in the unbioaugmented system. The effluent -N concentration of the bioaugmented system was stably below 8 mg·L after 20 d operation. In municipal wastewater systems with bioaugmentation, the effluent -N concentration was below 8 mg·L after 15 d operation. The average -N removal efficiency in unbioaugmentation system (about 82%) was lower compared with that in the bioaugmentation system. By inoculating the cold-adapted nitrite-oxidizing bacteria (NOB) into the SBRs after 10 d operation, the nitrite concentration decreased rapidly, reducing the -N accumulation effectively at low temperature. The functional microorganisms were identified by PCR-DGGE, including uncultured sp., uncultured sp., sp. and uncultured sp. The results suggested that the cold-adapted microbial agent of ammonia-oxidizing bacteria (AOB) and NOB could accelerate the start-up and promote achieving the stable operation of the low-temperature SBRs for nitrification.

关键词: nitrification     sequencing batch reactors (SBRs)     bioaugmentation     low temperature    

Process synthesis with simultaneous consideration of inherent safety-inherent risk footprint

Andreja Nemet, Jiří J. Klemeš, Zdravko Kravanja

《化学科学与工程前沿(英文)》 2018年 第12卷 第4期   页码 745-762 doi: 10.1007/s11705-018-1779-7

摘要:

Process plants should be designed to be economically viable and environmentally friendly, while also being operable and maintainable during process implementation. The safety of processes is among the most important considerations in obtaining results that are more acceptably realistic, as it is linked to the availability and reliability of the process. Inherent safety can effectively be enhanced in the early stages of the design, when the main decisions on process design are made. The aim of this study is to enhance and select the appropriate risk assessment method and to incorporate it into process synthesis, using a mathematical programming approach. A mixed-integer, nonlinear programming (MINLP) model was used for the synthesis of a methanol production process, considering risk assessment during the synthesis. Risk assessment is performed simultaneously with the MINLP process synthesis, where the risk is determined either for the whole process as overall risk, or on a per unit-of-a-product basis. For the latter, a new measurement is proposed: the inherent risk footprint. The results of a case study led to two main conclusions: (i) Significantly safer designs can be obtained at negligible economic expense, and (ii) at higher production capacities, a lower inherent risk footprint can be achieved. The results also indicate that designs obtained using this method can have significantly increased inherent safety, while remaining economically viable.

关键词: inherent safety     process design     simultaneous risk assessment     risk footprint     methanol process    

Effects of hydraulic retention time on nitrification activities and population dynamics of a conventional

Hongyan LI, Yu ZHANG, Min YANG, Yoichi KAMAGATA

《环境科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 43-48 doi: 10.1007/s11783-012-0397-8

摘要: The effects of hydraulic retention time (HRT) on the nitrification activities and population dynamics of a conventional activated sludge system fed with synthetic inorganic wastewater were investigated over a period of 260 days. When the HRT was gradually decreased from 30 to 5 h, the specific ammonium-oxidizing rates (SAOR) varied between 0.32 and 0.45 kg (kg mixed liquor suspended solids (MLSS)·d) , and the specific nitrate-forming rates (SNFR) increased from 0.11 to 0.50 kg (kg MLSS·d) , showing that the decrease in HRT led to a significant increase in the nitrite oxidation activity. According to fluorescence in situ hybridization (FISH) analysis results, the proportion of ammonia-oxidizing bacteria (AOBs) among the total bacteria decreased from 33% to 15% with the decrease in HRT, whereas the fraction of nitrite-oxidizing bacteria (NOBs), particularly the fast-growing sp., increased significantly (from 4% to 15% for NOBs and from 1.5% to 10.6% for sp.) with the decrease in HRT, which was in accordance with the changes in SNFR. A short HRT favored the relative growth of NOBs, particularly the fast-growing sp., in the conventional activated sludge system.

关键词: ammonia-oxidizing bacteria     hydraulic retention time     nitrification activity     nitrite-oxidizing bacteria     population dynamics    

Simultaneous saccharification and fermentation of wheat bran flour into ethanol using coculture of amylotic

K. Manikandan, T. Viruthagiri

《化学科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 240-249 doi: 10.1007/s11705-009-0205-6

摘要: Studies on simultaneous saccharification and fermentation (SSF) of wheat bran flour, a grain milling residue as the substrate using coculture method were carried out with strains of starch digesting and nonstarch digesting and sugar fermenting in batch fermentation. Experiments based on central composite design (CCD) were conducted to maximize the glucose yield and to study the effects of substrate concentration, pH, temperature, and enzyme concentration on percentage conversion of wheat bran flour starch to glucose by treatment with fungal α-amylase and the above parameters were optimized using response surface methodology (RSM). The optimum values of substrate concentration, pH, temperature, and enzyme concentration were found to be 200 g/L, 5.5, 65°C and 7.5 IU, respectively, in the starch saccharification step. The effects of pH, temperature and substrate concentration on ethanol concentration, biomass and reducing sugar concentration were also investigated. The optimum temperature and pH were found to be 30°C and 5.5, respectively. The wheat bran flour solution equivalent to 6% ( / ) initial starch concentration gave the highest ethanol concentration of 23.1 g/L after 48 h of fermentation at optimum conditions of pH and temperature. The growth kinetics was modeled using Monod model and Logistic model and product formation kinetics using Leudeking-Piret model. Simultaneous saccharificiation and fermentation of liquefied wheat bran starch to bioethanol was studied using coculture of amylolytic fungus and nonamylolytic sugar fermenting .

关键词: simultaneous saccharification and fermentation (SSF)     starch     coculture fermentation     statistical experimental design     bioethanol     Monod model    

Community dynamics of ammonia oxidizing bacteria in a full-scale wastewater treatment system with nitrification

Xiaohui WANG, Xianghua WEN, Hengjing YAN, Kun DING, Man HU

《环境科学与工程前沿(英文)》 2011年 第5卷 第1期   页码 92-98 doi: 10.1007/s11783-010-0254-6

摘要: To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria (AOB) in a full-scale wastewater treatment plant, the AOB community dynamics in a wastewater treatment system was monitored over one year. The community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism (T-RFLP) analysis of the gene. The T-RFLP results indicated that during the period of nitrification stability, the AOB community structure in the full-scale wastewater treatment system was relatively stable, and the average change rate every 15 d of the system was 6.6%±5.8%. The phylogenetic analysis of the cloned gene showed clearly that the dominant AOB in the system was spp. The results of this study indicated that throughout the study period, the AOB community structure was relatively stable in the full-scale wastewater treatment system with functional stability of nitrification.

关键词: ammonia-oxidizing bacteria (AOB)     community dynamics     terminal restriction fragment length polymorphism (T-RFLP)     nitrification performance    

Impact of total organic carbon and chlorine to ammonia ratio on nitrification in a bench-scale drinking

Yongji ZHANG, Lingling ZHOU, Guo ZENG, Huiping DENG, Guibai LI

《环境科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 430-437 doi: 10.1007/s11783-010-0247-5

摘要: Nitrification occurs in chloraminated drinking water systems and is affected by water quality parameters. The aim of this study was to investigate the impact of total organic carbon and chlorine to ammonia ratio on nitrification potential in a simulated drinking water distribution system as during chloramination. The occurrence of nitrification and activity of nitrifying bacteria was primarily monitored using four rotating annular bioreactors (RAB) with different chlorine to ammonia ratios and total organic carbon (TOC) levels. The results indicated that nitrification occurred despite at a low influent concentration of ammonia, and a high concentration of nitrite nitrogen was detected in the effluent. The study illustrated that reactors 1(R1) and 3 (R3), with higher TOC levels, produced more nitrite nitrogen, which was consistent with the ammonia-oxidizing bacteria (AOB) counts, and was linked to a relatively more rapid decay of chloramines in comparison to their counterparts (R2 and R4). The AOB and HPC counts were correlated during the biofilm formation with the establishment of nitrification. Biofilm AOB abundance was also higher in the high TOC reactors compared with the low TOC reactors. The chlorine to ammonia ratio did not have a significant impact on the occurrence of nitrification. Bulk water with a high TOC level supported the occurrence of nitrification, and AOB development occurred at all examined chlorine to ammonia dose ratios (3∶1 or 5∶1).

关键词: nitrification     drinking water     ammonia- oxidizing bacteria (AOB)     chloramines     organic carbon     heterotrophic bacteria    

标题 作者 时间 类型 操作

Simultaneous nitrification and denitrification in activated sludge system under low oxygen concentration

ZHANG Peng, ZHOU Qi

期刊论文

Factors affecting simultaneous nitrification and denitrification in an SBBR treating domestic wastewater

LI Jun, GU Guowei, PENG Yongzhen, WEI Su

期刊论文

Preparation and characterization of a novel microorganism embedding material for simultaneous nitrification

Ming Zeng, Ping Li, Nan Wu, Xiaofang Li, Chang Wang

期刊论文

Practical consideration for design and optimization of the step feed process

Shijian GE, Yongzhen PENG, Congcong LU, Shuying WANG

期刊论文

Control of sludge settleability and nitrogen removal under low dissolved oxygen condition

Zhaoxu PENG, Yongzhen PENG, Zhenbo YU, Xuliang LIU, Xiaoling LI, Randeng WANG

期刊论文

Enhanced nitrogen removal and microbial analysis in partially saturated constructed wetland for treating anaerobically digested swine wastewater

Zhenfeng Han, Ying Miao, Jing Dong, Zhiqiang Shen, Yuexi Zhou, Shan Liu, Chunping Yang

期刊论文

Methanation and chemolitrophic nitrogen removal by an anaerobic membrane bioreactor coupled partial nitrification

期刊论文

A heterotrophic nitrification-aerobic denitrification bacterium TJPU05 suitable for nitrogen removal

期刊论文

ROOT EXUDATES FROM CANOLA EXHIBIT BIOLOGICAL NITRIFICATION INHIBITION AND ARE EFFECTIVE IN INHIBITING

期刊论文

Improvement of nitrification efficiency by bioaugmentation in sequencing batch reactors at low temperature

Di CUI,Ang LI,Tian QIU,Rui CAI,Changlong PANG,Jihua WANG,Jixian YANG,Fang MA,Nanqi REN

期刊论文

Process synthesis with simultaneous consideration of inherent safety-inherent risk footprint

Andreja Nemet, Jiří J. Klemeš, Zdravko Kravanja

期刊论文

Effects of hydraulic retention time on nitrification activities and population dynamics of a conventional

Hongyan LI, Yu ZHANG, Min YANG, Yoichi KAMAGATA

期刊论文

Simultaneous saccharification and fermentation of wheat bran flour into ethanol using coculture of amylotic

K. Manikandan, T. Viruthagiri

期刊论文

Community dynamics of ammonia oxidizing bacteria in a full-scale wastewater treatment system with nitrification

Xiaohui WANG, Xianghua WEN, Hengjing YAN, Kun DING, Man HU

期刊论文

Impact of total organic carbon and chlorine to ammonia ratio on nitrification in a bench-scale drinking

Yongji ZHANG, Lingling ZHOU, Guo ZENG, Huiping DENG, Guibai LI

期刊论文