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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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Board-invited review: Sensitivity and responses of functional groups to feed processing methods on a molecular basis 被引量:2
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作者 Peiqiang Yu 《Journal of Animal Science and Biotechnology》 SCIE CAS 2013年第1期1-4,共4页
In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore... In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore produce unique molecular vibration spectral profile. Feed processing has been used to improve nutrient utilization for many years. However, to date, there was little study on processing-induced changes of feed intrinsic structure and functional groups on a molecular basis within intact tissue. This is because limited research technique is available to study inherent structure on a molecular basis. Recently bioanalytical techniques: such as Synchrotron Infrared Microspectroscopy as well as Diffuse Reflectance Infrared Fourier Transform molecular spectroscopy have been developed. These techniques enable to detect molecular structure change within intact tissues. These techniques can prevent destruction or alteration of the intrinsic protein structures during processing for analysis. However, these techniques have not been used in animal feed and nutrition research. The objective of this review was show that with the advanced technique, sensitivity and responses of functional groups to feed processing on a molecular basis could be detected in my research team. These functional groups are highly associated with nutrient utilization in animals. 展开更多
关键词 Sensitivity and responses of functional groups Molecular structures Feed processing Nutrient utilizationand availability
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Optimization of Screening Method for Feed Nutrition and Processing Conditions
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作者 YangYun-qing WangYi-tong 《Journal of Northeast Agricultural University(English Edition)》 CAS 1999年第2期112-116,共5页
On the basis of regressional relationship between nutritional indexes and technological conditions,when confronted with feed quality that contains multiple nutritional indexes,a comprehensive equation of evaluating fe... On the basis of regressional relationship between nutritional indexes and technological conditions,when confronted with feed quality that contains multiple nutritional indexes,a comprehensive equation of evaluating feed quality was developed by using fuzzy mathematical method at first in this study,and then the optimum technological conditions were established by introduction of statistical frequency analysis method pursuant to the comprehensive evaluating equation mentioned above compared with conventional multi-aim nonlinear programming,this method can lead to easy solutions,and also can make adjustment of the importance of nutritional indexes to feed quality according to practical considerations.An example was given of soybean extruding to show how the method worked. 展开更多
关键词 feed processing nutritional index technological condition OPTIMIZATION
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Enhanced a novel β-agarase production in recombinant Escherichia coli BL21(DE3) through induction mode optimization and glycerol feeding strategy
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作者 CHAN Zhuhua CHEN Xinglin +4 位作者 HOU Yanping GAO Boliang ZHAO Chungui YANG Suping ZENG Runying 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第2期110-118,共9页
Agarases are hydrolytic enzymes that act on the hydrolysis of agar and have a broad range of applications in food,cosmetics and pharmaceutical industries. In this study, a glycerol feeding strategy based on induction ... Agarases are hydrolytic enzymes that act on the hydrolysis of agar and have a broad range of applications in food,cosmetics and pharmaceutical industries. In this study, a glycerol feeding strategy based on induction mode optimization for high cell density and β-agarase production was established, which could effectively control acetate yield. First, exponential feeding strategy of glycerol with different overall specific growth rates(μ) was applied in the pre-induction phase. The results showed that the low μ(μ=0.2) was suggested to be the optimal for cell growth and β-agarase production. Second, the effects of induction temperature and the inducer concentration on cell growth and β-agarase production were investigated in the post-induction phase. When induced by isopropyl-β-d-thiogalactoside(IPTG), the strategy of 0.8 mmol/L IPTG induction at 20℃ was found to be optimal for β-agarase production. When cultivation was induced by continuous lactose feeding strategy of 1.0 g/(L·h), the β-agarase activity reached 112.5 U/mL, which represented the highest β-agarase production to date.Furthermore, the β-agarase was capable of degrading G. lemaneiformis powder directly to produce neoagarooligosaccharide, and the hydrolysates were neoagarotetraose(NA4) and neoagarohexaose(NA6). The overall research may be useful for the industrial production and application of β-agarase. 展开更多
关键词 β-agarase Escherichia coli process optimization glycerol feeding strategy neoagarooligosaccharide
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Theoretical evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process 被引量:4
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作者 祝贵兵 彭永臻 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2006年第3期263-266,共4页
Evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process at the standpoint of reaction kinetics and process kinetics was conducted. Theoretical biological nitrogen removal efficiency was deduce... Evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process at the standpoint of reaction kinetics and process kinetics was conducted. Theoretical biological nitrogen removal efficiency was deduced based on the mass balance of nitrate in the last stage. The comparison of pre-denitrification process and step feed process in the aspects of nitrogen removal efficiency, volume of reactor and building investment was studied, and the results indicated that step-feed anoxic/oxic activated sludge process was superior to pre-denitrification process in these aspects. 展开更多
关键词 step feed process biological nitrogen removal reaction kinetics process kinetics
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Using vibrational infrared biomolecular spectroscopy to detect heat-induced changes of molecular structure in relation to nutrient availability of prairie whole oat grains on a molecular basis
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作者 M. D. Mostafizar Rahman Katerina Theodoridou Peiqiang Yu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第1期128-133,共6页
Background: To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this stud... Background: To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this study was to investigate the effect of heat processing methods on interaction between nutrient availability and molecular structure in terms of functional groups that are related to protein and starch inherent structure of oat grains with two continued years and three replication of each year.Method: The oat grains were kept as raw(control) or heated in an air-draft oven(dry roasting: DO) at 120 °C for 60 min and under microwave irradiation(MIO) for 6 min. The molecular structure features were revealed by vibrational infrared molecular spectroscopy.Results: The results showed that rumen degradability of dry matter, protein and starch was significantly lower(P 〈0.05) for MIO compared to control and DO treatments. A higher protein α-helix to β-sheet and a lower amide I to starch area ratio were observed for MIO compared to DO and/or raw treatment. A negative correlation(-0.99, P 〈 0.01)was observed between α-helix or amide I to starch area ratio and dry matter. A positive correlation(0.99, P 〈 0.01) was found between protein β-sheet and crude protein.Conclusion: The results reveal that oat grains are more sensitive to microwave irradiation than dry heating in terms of protein and starch molecular profile and nutrient availability in ruminants. 展开更多
关键词 Dry roasting Feed processing Microwave irradiation Modeled cereal grains Molecular structure Nutrient availability
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The Method and Experiment Research on Down-stroke Abrasive Belt Grinding under Micro Feeding for Noise Reduction Surface
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作者 Ying Liu Shayu Song +4 位作者 Guijian Xiao Yi He Yun Huang Shuai Liu Suolang Jiahua 《Journal of Bionic Engineering》 SCIE EI CSCD 2021年第4期958-973,共16页
This paper proposes a down-stroke abrasive belt grinding under micro feeding for noise reduction surface.Firstly,a physical model of processing under micro feeding for noise reduction structure was established.Based o... This paper proposes a down-stroke abrasive belt grinding under micro feeding for noise reduction surface.Firstly,a physical model of processing under micro feeding for noise reduction structure was established.Based on the flexible contact characteristics of abrasive belt grinding and Hertz contact theory,a mathematical model suitable for this method was established,considering vibration and abrasive belt wear.Secondly,a simulation analysis was carried out.Then,an experimental platform was built to analyze the influence of process parameters on surface roughness and surface microstructure,with the model verified.Finally,the propeller with pit structure was simulated,and the noise reduction performance of the propeller under this method and general abrasive belt grinding was compared and analyzed.The results show that the maximum error of the model based on proposed method does not exceed 10%,and the coincidence degree of the minimum error point can reach 90%at lower feed speed and higher linear velocity of the abrasive belt.The noise reduction effect of the propeller with pit-shaped surfaces can reach 35%.Through the above analysis,the proposed method can be used for the processing of noise reduction surfaces. 展开更多
关键词 abrasive belt grinding noise reduction surface non-smooth surfaces micro feeding processing
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Advance on the production of polyhydroxyalkanoates by mixed cultures
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作者 LÜ Yaoping 《Frontiers in Biology》 CSCD 2007年第1期21-25,共5页
Polyhydroxyalkanoates(PHAs)are the polymers of hydroxyalkanoates that accumulate as carbon/energy or reducing-power storage material in various microorganisms.PHAs have attracted considerable attention as biodegradabl... Polyhydroxyalkanoates(PHAs)are the polymers of hydroxyalkanoates that accumulate as carbon/energy or reducing-power storage material in various microorganisms.PHAs have attracted considerable attention as biodegradable substitutes for conventional polymers.Until now,however,industrial production of PHAs has encountered only limited success.The main barrier to the replacement of synthetic plastics by PHAs has been the higher cost.The use of mixed cultures and renewable sources obtained from waste organic carbon can substantially decrease the cost of PHA and increase their market potential.This work reviews two main methods of PHA production by mixed cultures,anaerobic-aerobic processing and aerobic transient feeding processing,and analyzed the metabolic and effective factors. 展开更多
关键词 polyhydroxyalkanoates(PHAs) mixed cultures anaerobic-aerobic processing aerobic transient feeding processing
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