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关键词： 膜生物反应器   污水处理   应用   组合工艺  

摘要： 随着污水排放标准不断提高,膜生物反应器(MBR)的研究和应用受到了研究者们的广泛关注。本文介绍了膜生物反应器的基本原理,阐明了该工艺在现阶段与其他工艺结合的应用现状,总结了膜生物反应器在污水处理中的优点,并指出了其在未来的应用前景和发展方向。

关键词： Interfacial interaction   Membrane fouling   Surface topography   Gaussian distribution   Membrane bioreactor  

摘要： While membrane bioreactor (MBR) technology is generally considered as one of the most promising technologies for wastewater treatment and recovery, membrane fouling remains the major obstacle limiting its applications. Interfacial interactions, which critically determine adhesion process and membrane fouling, were investigated in this study. It was found that, natural membrane surface was of a Gaussian surface obeying Gaussian distribution. A Gaussian approach integrating Fourier transform technique, Gaussian distribution and spectrum method was deduced to simulate rough surface topography of membrane. Thereafter, surface element integral (SE!) method, together with composite Simpson rule and triangulation of Gaussian surface was proposed to calculate interfacial interactions. By using the unified method, quantification of interfacial interactions with a Gaussian membrane surface was realized for the first time to date. It was further found that, membrane surface topography had profound impacts on interfacial interactions and adhesive fouling in the MBR. The deduced method can be used to address impacts of various factors on interfacial interactions and adhesive fouling, posing in-depth thermodynamic insights into membrane fouling and pointing towards its widespread potential in fouling research in MBRs. (C) 2018 Elsevier inc. All rights reserved.

关键词： PAH   Benzo(a)pyrene   Benzo(a)anthracene   Bioreactors   Microalgae   Alginate   Water bioremediation  

摘要： Polycyclic aromatic hydrocarbons (PAHs), especially those having four or more rings, are abundant and toxic environmental contaminants that are highly persistent and difficult to remove from contaminated ecosystems. Bioreactors with microalgae have been used to remove some low-molecular-weight PAHs. Immobilization is a good choice for the recovery of biomass from reactors once its function of removing contaminants is fulfilled. Alginate is a natural material that is transparent, is permeable and acts as a protective barrier against other microorganisms and harmful particulates suspended in water. Therefore, in this study, we designed and evaluated four mini-bioreactors packed with alginate beads that contain two microalgal species, Selenastrum capricornutum and Scenedesmus acutus which are capable of removing the high-molecular-weight PAHs benzo(a)anthracene and benzo(a)pyrene. One of the bioreactors was a batch reactor with a continuous magnetic stirring tank, and the other bioreactors were enclosed tubular bioreactors operating in semi-continuous mode with two cycles. The influence of parameters such as the reactor shape, stirring speed, flow, number of alginate beads, number of cells and cell species ratio, as well as the time of contact and the use of two operation cycles were studied. The amounts of the remaining PAHs after exposure tests with microalgae were determined. It was found that the shape and the mode of operation of the bioreactor markedly influenced the efficiency of removal. The removal capacity of these mini-bioreactors and the advantages and the disadvantages of using these mini-bioreactors were analyzed. (C) 2017 Elsevier B.V. All rights reserved.

关键词： 生物膜   多孔介质   生化反应   数值重构  

摘要： 采用介观尺度的格子Boltzmann数值算法研究平板式膜生物反应器内生物膜结构对生化反应及流动传输的影响.利用四参数随机生成法重构不同多孔结构的生物膜,计算中耦合多块模型获得局部详细信息且提高计算效率.结果表明：生物膜结构稳定条件下,孔隙率增大有利于主流区与生物膜内的物质传输,可以提高底物降解效率;孔隙率一定条件下,改变生物膜的孔隙结构分布可以加强传质,强化生化反应过程,提高底物降解效率.

关键词： 杂交瘤细胞   单克隆抗体   生物反应器   中空纤维  

摘要： 单克隆抗体在生物学和医学研究领域中显示了极大的应用价值,是免疫检验中的新型试剂,是生物治疗的导向武器。作为医学检验试剂,单克隆抗体可以充分发挥其优势,如特异性好,灵敏度高,更便于质量控制,利于标准化和规范化。传统的方法是利用小鼠腹水制备单克隆抗体,但是近几十年杂交瘤细胞体外大规模培养制备单克隆抗体技术也在不断发展。特别是单克隆抗体在疾病诊断和治疗方面的需求,更进一步促进了杂交瘤细胞体外培养生产技术的发展,体外培养杂交瘤细胞生产的单克隆抗体已应用到许多方面。由于杂交瘤细胞的半贴壁性质,无论是悬浮培养还是贴壁培养,均可进行杂交瘤细胞的体外大规模培养。针对应用于体外诊断试剂的杂交瘤细胞体外培养制备单克隆抗体进行综述,主要包括中空纤维细胞培养和生物反应器细胞培养方法,以及不同培养方法优化的进展。

关键词： 气体分布器   孔尺寸   气泡   CO2传递   微藻  

摘要： CO_2气体可为微藻光合作用提供必需的碳源,CO_2在藻液中的混合、溶解及传输特性显著影响了微藻的生长固碳.在微藻光生物反应器中,气泡在藻液中的生长、脱离、聚并、上升等动力学行为主要由气体分布器决定.本文以气体分布器为研究对象,研究在不同孔径及孔间距下对15%(V/V)CO_2气体在悬浮液中的气泡行为、CO_2溶解与混合特性以及对微藻生长固碳的影响.结果表明:气泡上升速度随气体分布器孔径及孔间距的减小而减小,导致CO_2气泡在藻液中停留时间增加,强化了CO_2溶解传输,CO_2体积传质系数提高了143%,混合时间降低了24%,最终使微藻生物质浓度提高18.8%,固碳速率提高23.2%.

关键词： Cell encapsulation   Mesenchymal stem cells   Composite microbeads   Osteogenic differentiation   Microgravity bioreactor   Bone tissue engineering  

摘要： The objective of this study is to evaluate the in vitro and in vivo osteogenic potential of rat bone marrow mesenchymal stem cells (BM-MSCs) using chitosan/hydroxyapatite (C/HAp) microbeads as encapsulation matrix under osteoinductive medium and dynamic culture conditions. The degradation characteristics of C/HAp microbeads were evaluated under in vitro and in vivo conditions for 180days. BM-MSCs were encapsulated in C/HAp microbeads with >85% viability, and were cultured in a slow turning lateral vessel-type rotating bioreactor simulating microgravity conditions for 28days, under the effect of osteogenic inducers. MTT assay showed that the metabolic activity of encapsulated cells was preserved >80% after a week. In vitro experiments confirmed that the encapsulated BM-MSCs differentiated into osteoblastic cells, formed bone-like tissue under osteogenic microgravity bioreactor conditions. Preliminary in vivo study indicated C/HAp microbeads containing BM-MSCs were able to repair the surgically-created small bone defects in the rat femur. BM-MSCs-C/HAp composite microbeads may have potential for modular bone regeneration.

关键词： bacteriophages   continuous production   E. coli   mathematical modelling   phage T3   process intensification   synthetic medium  

摘要： Future industrial demand for large quantities of bacteriophages e.g., for phage therapy, necessitates the development of scalable Good Manufacturing Practice compliant (cGMP) production platforms. The continuous production of high titres of E coli T3 phages (10(11) PFU mL(-1)) was achieved using two continuous stirred tank bioreactors connected in series, and a third bioreactor was used as a final holding tank operated in semi-batch mode to finish the infection process. The first bioreactor allowed the steady-state propagation of host bacteria using a fully synthetic medium with glucose as the limiting substrate. Host bacterial growth was decoupled from the phage production reactor downstream of it to suppress the production of phage-resistant mutants, thereby allowing stable operation over a period of several days. The novelty of this process is that the manipulation of the host reactor dilution rates (range 0.1-0.6 hr(-1)) allows control over the physiological state of the bacterial population. This results in bacteria with considerably higher intracellular phage production capability whilst operating at high dilution rates yielding significantly higher overall phage process productivity. Using a pilot-scale chemostat system allowed optimisation of the upstream phage amplification conditions conducive for high intracellular phage production in the host bacteria. The effect of the host reactor dilution rates on the phage burst size, lag time, and adsorption rate were evaluated. The host bacterium physiology was found to influence phage burst size, thereby affecting the productivity of the overall process. Mathematical modelling of the dynamics of the process allowed parameter sensitivity evaluation and provided valuable insights into the factors affecting the phage production process. The approach presented here may be used at an industrial scale to significantly improve process control, increase productivity via process intensification, and reduce process manufact

关键词： angiogenesis   bioengineering   cell therapy   stem cells   tissue engineering   transplantation   vascularised chamber  

摘要： Vascularisation is key to developing large transplantable tissue constructs capable of providing therapeutic benefits. The vascularised tissue engineering chamber originates from surgical concepts in tissue prefabrication and micro-surgery. It serves as an in vivo bioreactor in the form of a closed, protected space surgically created and embedded within the body by fitting a non-collapsible chamber around major blood vessels. This creates a highly angiogenic environment which facilitates the engraftment and survival of transplanted cells and tissue constructs. This article outlines the chamber concept and explores its application in the context of recent advances in biomedical engineering, and how this can play a role in the future of cell therapies and regenerative medicine.

关键词： Direct contact membrane distillation (DCMD)   Anaerobic membrane bioreactor effluent   Optimum operating conditions   Treatment efficiency   Membrane fouling  

摘要： This study was carried out by applying the direct contact membrane distillation (DCMD) into the treatment of effluent from anaerobic membrane bioreactor. The treatment efficiency of DCMD was highly emphasized, which was expected to be improved through the optimization of operating conditions. Three operating conditions, including temperature difference, cross-flow velocity and membrane pore size, were considered. The relative flux (the ratio of actual flux to initial flux) increased from 0.50 to 0.98 as the operating conditions changed and that was enhanced by the increment of temperature difference and cross-flow velocity. Regarding the wastewater treatment efficiency, except for ammonia nitrogen, the interception ratio was greater than 90.0%, which even reached 99.0% for CODCr, protein and polysaccharide by optimizing operating conditions. In addition, the interception ratio of PO43--P, almost reached 100.0% under any operating condition. Further study about membrane fouling was carried out, and the crystallization fouling was found to be the main fouling type. (C) 2018 Elsevier Ltd. All rights reserved.