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关键词： 微藻   光生物反应器   螺旋肋   光暗循环频率   光暗循环强化效率  

摘要： 对一种新型带螺旋肋的光生物反应器进行数值模拟,采用粒子追踪模型模拟微藻在反应器中的运动情况,分析微藻细胞经历的光暗循环频率f_(av)、反应器光暗循环强化效率η随螺旋肋螺距P_s的变化情况。结果表明,随着P_s的增加,f_(av)、η出现峰值。f_(av)在P_s=400mm的反应器中最大,为0.5794Hz;η的峰值则出现在P_s=800mm的反应器中。分析发现,在0.5m/s的进口速度下,P_s=400mm、600mm、800mm时,螺旋肋的存在对提高f_(av)有正面作用,P_s=200mm、1000mm时,螺旋肋的存在限制了f_(av)的提高。可通过调整螺旋肋的结构参数达到对流场的调整,从而改变微藻所受光暗循环的情况。

关键词： AnMBR   厌氧发酵   厨余垃圾   城市污水  

摘要： 厌氧膜生物反应器(anaerobic membrane bioreactor,AnMBR)是一种耦合了厌氧发酵和膜工艺的新型废水生物处理技术。其优点包括出水水质优良、有机负荷高、污泥产率低以及生物甲烷回收等。归纳了厌氧发酵的原理,常见厌氧膜生物反应器的结构和种类,以及厌氧膜生物反应器的发展历程及其应用。详细介绍了笔者的最新研究成果:厌氧膜生物反应器在高浓度厨余垃圾处理中的应用,及其在城市污水处理中的研究进展。最后总结了该工艺的应用及发展现状,指出其在高浓度有机废水处理中拥有广阔的应用前景。

关键词： MBR   Design   Wastewater   Test   Reuse  

摘要： The objective of this paper is to deal with the design of a pilot-scale submerged membrane bioreactor (MBR) and a short-term functionality test to be performed with textile wastewater. The design calculations were done based on the design parameters analysed from local textile wastewater and typical values of activated sludge kinetic coefficients. Other process parameters like bioreactor volume (tank size), hydraulic residence time (HRT), biomass loading (F/M ratio), oxygen demand, etc., were calculated depending on the real textile wastewater characteristics. Taking the design basis into consideration, a pilot-scale MBR was constructed equipped with LabVIEW programme- and sensors-controlled computer system. Based on the theoretical calculations, the hydraulic volume of the MBR reactor was around 56.6L with flat sheet membranes (3 sheets, with 25cmx25cm dimensions of each sheet) with HRT of 16.9h. Finally, performance tests for 6weeks were carried out in a local (Darmstadt, Germany) laundry textile wastewater to test the functionality of MBR pilot plant. Under the operating conditions of 250mbar suction pressure and 12g/L of MLSS, the COD removal efficiency was around 90% for 800-3500mg/L inlet COD fed to the membrane bioreactor.

关键词： Bioreactor cultivation   Cell suspension   Elicitation   Labiateae   Triterpenoids  

摘要： The competence of Ocimum basilicum suspension culture for the production of pharmacologically distinguished triterpenoids had been explored to meet their escalating demand with inequitable natural resources. The production of three pentacyclic triterpenesbetulinic acid (BA), ursolic acid (UA) and oleanolic acid (OA), could be achieved for the first time in the O. basilicum suspension culture, together with the prevalently occurring rosmarinic acid (RA). The production of RA was most abundant (15.730.28mg/g DW) followed by that of BA (14.63 +/- 0.21mg/g DW), UA (4.71 +/- 0.23mg/g DW) and OA (0.91 +/- 0.02mg/g DW) in reducing order on their respective optimum cultivation period. Compared to the in-vivo control leaves, the suspension cell revealed almost 3.25-, 2.89-, and 1.79-folds higher OA, UA and RA contents, respectively. The BA synthesizing power of suspension cells exemplified notable trend as its presence in the control leaves remained obscured. By and large, cultivation in a 10l bioreactor and elicitation with methyl jasmonate in bioreactor and shake flask improved the cumulative productivities of the targeted metabolites with reciprocated divergence in the amounts of the two isomers, i.e., UA and OA. The overall findings of the present study bear special merit in realising the global demand of these multiple terpenoids in a single culture system of O. basilicum, which remained unrevealed so far. Key MessageFirst report towards the in vitro production of multiple pharmacologically distinguished, high demand triterpenoidsbetulinic acid (BA), ursolic acid (UA) and oleanolic acid (OA), along with rosmarinic acid (RA) in suspension culture of Ocimum basilicum. Notable yield enhancement through bioreactor cultivation and strategic elicitation with methyl jasmonate in shake flask and bioreactor added additional merit to this study in realizing the global demand of these multiple terpenoids in a single culture system of O. basilicum.

关键词： Inverted frusto-conical shaking bioreactor   Scale up   Low shear stress   Computational fluid dynamics   Numerical simulation   Suspension cell culture  

摘要： Shear stress is one of the key factors affecting the large-scale culture of mammalian cells. In this study, numerical simulation based on computational fluid dynamics was used to conduct a flow-field analysis of 7, 50, 200, and 1200 L inverted frusto-conical shaking bioreactors. The results show that the shear rate, specific mass transfer area (a), and volumetric oxygen mass transfer coefficient (k(L)a) gradually decreased as the scale of the bioreactor increased. Through application of BHK21 and CHO cells in 7, 200, and 1200 L bioreactors, it was found that the cell density and antibody expression level increased as the volume of the bioreactor increased. Moreover, the antibody expression level in a 1200 L bioreactor was nearly 30% and 35% higher than that of 7 and 200 L bioreactors, respectively. The results demonstrate that the environment with a larger volume is more suitable for the growth and antibody expression of CHO cells, indicating shear stress might be the most critical factor affecting the scale-up of mammalian cells.

关键词： Bioreactor landfill   Leachate injection   Waste   Landfill stability   Subgrade  

摘要： In this study, the design factors of bioreactor landfill were investigated using the coupled leachate-infiltration and slope-stability analyses for various conditions of leachate injection, subgrade, and landfill waste. The factor of safety (FS) decreased with leachate injection where larger and faster reduction of FS was observed for higher injection pressure. The upper-placed injection pipes within landfill induced larger wet zone. The number of injection pipe indicated some effect on FS for the lower-placed case. The optimum location of injection pipes was at heights above Y/H = 0.33. The highest location of injection pipes should be identified considering landfill property and geometry conditions. Shallower and smaller slip surface within landfill was formed for strong subgrade whereas deeper, larger slip surface with lower FS was formed for soft subgrade. For low-compaction landfills, leachate injection reached the steady state and perched leachate was formed. The values of FS for high- and low-compaction cases were similar for soft subgrade indicating that the compaction of landfill waste does not affect the overall stability of landfill significantly for soft subgrades.

关键词： Cartilage tissue engineering   CPM (continuous passive motion)   Ex-vivo system   Knee joint   SLUP (salt leaching using powder)  

摘要： Efforts to minimize the sacrifice of laboratory animals have become a recent worldwide trend. This trend has triggered a number of studies toward developing effective methods to replace the animal experiments. In this study, we developed a biomimetic bioreactor system that simulates the movements of the human knee joint. The system consists of a knee-joint drive and a unit capable of culturing cells at the joint surface. The knee-joint drive is designed to apply dynamic stimulation similar to the real bending motion of the knee joint. We employed a commercial incubator for comparative evaluation and validation of our laboratory-made cell-culture unit mounted in a bioreactor. The results revealed that the ability of the proposed system in culturing cells was similar to that of the commercial incubator. The cell culture was evaluated by dividing the knee joint into zones according to the size of the stimulus. The results confirmed that the cell assessment stimulated by the knee-joint movement was two times higher than that having no stimulation. Overall, the study helped establish that the cell characteristics is more effective when an appropriate external stimulus is applied according to the target tissue. The study is also expected to form the basis for implementing an ex-vivo environment that can potentially replace animal and cadaver experiments in the future. In the future, follow-up studies will be conducted on the in-vivo environment and the characteristics of each organ and tissue for effective tissue regeneration.

关键词： Dracocephalum forrestii   Bioreactor   Rosmarinic acid   Salvianolic acid B   Antimicrobial and antioxidant activity  

摘要： Dracocephalum forrestii is known as a medicinal plant in China. The present work evaluates the potential of its shoots to biosynthesise phenolic compounds during bioreactor cultivation. Qualitative UPLC-PDA-ESI-MS analysis revealed the presence of nine caffeic acid derivatives in the hydromethanolic extract. Quantitative UPLC-PDA analysis then found the predominant compounds to be rosmarinic acid (17.90 mg/g DW) and salvianolic acid B (6.5 mg/g DW). Regarding antioxidant activity, the extract demonstrated strong potential to scavenge both DPPH and O-2(center dot-) radicals (NBT) (IC50 values 30.67 mu g/ml and 69.06 mu g/ml, respectively) and reduce Fe3+ ions (1319 mu M Fe(II)/g DW of extract-FRAP test). The extract also showed moderate growth-limiting activity against 13 selected pathogenic bacteria and fungi strains, with the MIC and MBC values ranging from 2.5 to 5.0 mg/ml in most cases.

关键词： Membrane bioreactor   Fouling   Membrane resistance   Connectionist approaches   Statistical analysis  

摘要： Membrane fouling as a major concern in development and optimization of membrane bioreactor (MBR) technologies has been the focus of numerous engineering and research investigations. Considering the complexity of membrane fouling occurrence, mathematical modelling techniques have been progressively proposed to forecast this phenomenon for optimizing MBR performance. A majority of the models are not reliable and accurate enough in terms of theoretical and practical prospects. In this research work, smart methods including artificial neural network (ANN), gene expression programming (GEP), and least square support vector machine (LSSVM) are suggested to avoid utilization of complex modelling methodologies and costly and time-consuming measurements. The developed models relate fouling resistance to key parameters such as permeate flux, temperature, and transmembrane pressure. To enhance the performance of conventional connectionist tools, particle swarm optimization (PSO) algorithm with global optima is utilized. This study aims to simulate the MBR efficiency by calculating membrane fouling resistance. The performance of the smart models is evaluated based on the mean squared error (MSE), maximum absolute percentage error (MAAPE), minimum absolute percentage error (MIAPE), and coefficient of determination (R-2). The results reveal that the developed LSSVM tool has the lowest MSE (0.0002), MAAPE (3.18), and MIAPE (0.01), and the highest R-2 (0.99) in the testing phase. The transmembrane pressure and permeate flux are the most important parameters affecting the membrane fouling resistance. This study can help to obtain a better understanding of membrane fouling process to achieve optimal conditions for MBR systems in terms of design, operation, and optimization prospects. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： beta-Elemene   Bioreactor   Cell culture   Rhizoma zedoariae   Secondary metabolism  

摘要： We presented a two-stage combined bioreactor system consisting of a stir-tank and an airlift column, and challenged with Rhizoma zedoariae cell suspensions for beta-elemene production. Two-stage culture was initiated when the cell concentration in both vessels was maintained at an appropriate density. The cells were proliferated in stirred-tank with the maximal growth rate of 0.17d(-1) to present enough cells for beta-elemene synthesis. In the airlift column, continuous cell separation from culture medium was achieved by using a cell retention device based on centrifugal and gravity settling when the system was performed in perfusion mode. The results indicated that additives can efficiently promote the accumulation of beta-elemene in R. zedoariae cells. In addition, the beta-elemene content showed higher levels in cell lines of overexpressing 3-hydroxy-3-methylglutaryl coenzyme-A reductase, Farnesyldi phosphate synthase, and ST02C genes.