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关键词： Submerged module   Side-stream module   Outer-selective hollow fiber   Membrane fouling   Operating cost   Osmotic membrane bioreactor  

摘要： This study investigated the comparative performances, fouling mitigation efficiencies, and operational costs of sidestream and submerged osmotic membrane bioreactors (OMBR) systems using an outer-selective hollow fiber thinfilm composite forward osmosis (OSHF TFC FO) membrane. Generally, the submerged OMBR system exhibited the higher fouling mitigation efficiency and a much slower flux decline rate when compared with that of the sidestream system. The side-stream OMBR system demonstrated an initial water flux of 15.8 LMH using 35 g/L NaCl as the draw solution, which was 2-fold higher than that of the submerged system when at its optimal performance. However, salinity accumulation in the reactor of the side-stream system was at a higher rate than for the submerged OMBR system. Both OMBR systems showed comparably high pollutant removal efficiencies over the experimental period. Annual operating costs for the side-stream OMBR system has been estimated to be 38% higher (OPEX) than for the submerged system. Membrane replacement cost accounted for the majority of the OPEX, over 89%, while the energy consumption and cleaning costs only accounted for relatively small portions. Therefore, reducing the membrane replacement cost is critical to realizing the commercial viability of the submerged OMBR system.

关键词： 微藻培养   光生物反应器   测控系统   培养试验  

摘要： [目的]为提高微藻光生物反应器的培养参数控制能力,建立起先进、稳定的微藻培养测控系统,进而提高微藻生产产量和品质。[方法]通过分析微藻培养过程参数确定拟设计综合测控系统的监测参数和控制参数,设计并研制出通用型综合测控系统,开展完整批次的微藻培养测试。[结果]测控系统稳定运行,光照、温度、pH、溶解氧的变化趋势相互印证,叶绿素荧光参数和RGB谱很好地反映出微藻细胞光合系统的生理状态,系统测量的自动OD与干重都有很好的线性关系,可以直接反映微藻生长密度。[结论]微藻综合测控系统设计合理、运行稳定、自动化程度高,很好地反映了微藻生产过程中的状态和趋势,实现了微藻生产过程的可控培养。

关键词： PTFE复合膜   AO-MBR   化工废水  

摘要： 通过交联改性法对PTFE平板进行膜亲水改性,测试了亲水改性后PTFE平板膜的耐化学腐蚀性。通过亲水改性平板膜裹缠中空纤维膜的方式制备了PTFE复合膜,研究以PTFE复合膜为膜组件的AO-MBR系统对实际化工废水的处理效果,观察处理过程中膜通量与膜压差的变化,并对膜污染与清洗进行了相应探究。结果表明:在处理高浓度难降解化工废水时,采用PTFE复合膜的MBR工艺表现出良好的处理效果,AO-MBR系统对COD和NH3-N的去除率能稳定达到92%和90%;PTFE复合膜抗膜污染性能优异,耐化学腐蚀性强;PTFE复合膜处理实际化工废水效果良好,膜出水稳定。

关键词： 电流   废水   生物反应器   反硝化脱氮   酶   胞外聚合物   絮凝性  

摘要： AO工艺利用硝化液内循环实现生物脱氮,很难保证缺氧区的缺氧条件,导致脱氮效果不理想,污泥絮凝性差。为了达到强化生物脱氮的目的,本研究采用外加电流提高缺氧区的污泥活性和生物絮凝性,探索不同电流强度下污泥接触角、zeta电位和污泥粒径的变化,结合三维荧光光谱(3D-EEM)与傅里叶变换红外光谱(FTIR)分析胞外聚合物(EPS)的组成,考察外加电流对污染物去除和污泥性质的影响。结果表明:当电流强度低于30mA时,随着电流强度的增加,TN和COD去除率提高,酶活性增强。当电流强度为30mA时,ORP为-135mV,硝酸盐还原酶活性达到最强[0.37μg/(mg·min)],TN去除率达到最高79.43%;当电流强度为40mA时,脱氢酶活性达到最强[50.86mg/(L·h)],COD去除率达到最高80.65%。当电流强度低于40mA时,随着电流强度的提高,蛋白质(PN)与多糖(PS)的比值增加,污泥接触角增大,zeta电位减小,平均粒径升高,污泥絮凝性增强;由3D-EEM和FTIR分析可知,色氨酸和酪氨酸类的荧光强度增强,EPS的官能团无明显变化。当电流强度为40mA时,污泥重絮凝能力(FA)为40.33%,出水悬浮物(ESS)为13.95mg/L,污泥容积指数(SVI)为66.5mL/g,污泥絮凝性最好。随着电流强度的继续提高,污泥絮凝性逐渐变差。因此,将电流强度控制在40mA,可以同时实现提高生物脱氮效率和污泥絮凝性的目的。

关键词： Bioreactor   Reciprocal mixing   Low shear stress   Chinese hamster ovary cells   Computational fluid dynamics analysis  

摘要： We have constructed a new bioreactor with reciprocal mixing that is better suited for the cultivation of delicate animal cells. In-silico simulation (computational fluid dynamics) suggested both maximum and average shear stresses in the bioreactor with reciprocal mixing to be remarkably lower than in a conventional bioreactor with rotary mixing. Although we could not find any difference in growth speed and cell density between the bioreactors with reciprocal and rotary mixing, we did find cell viability in the reciprocal-mixing bioreactor to be retained longer than in the rotary paddle bioreactor. This implied that cell culture in a bioreactor with reciprocal mixing could be prolonged for the production of target proteins. Leakage of lactate dehydrogenase activity into the culture medium was suppressed much more in the reciprocal-mixing bioreactor than in the rotary-paddle one. Production of human tissue plasminogen activator in the former system was also observed to be much higher than in the latter. Therefore, a bioreactor with reciprocal mixing was concluded to be better suited for the cultivation of animal cells and efficient production of proteins, such as antibody drugs and various growth factors. (c) 2021, The Society for Biotechnology, Japan. All rights reserved.

关键词： Algal biomass   Echeuma spinosum   Biohydrogen    Dynamic membrane bioreactor   Propionic acid  

摘要： This study aimed to achieve continuous biohydrogen production from red algal biomass using a dynamic membrane bioreactor (DMBR). The DMBR was continuously fed with pretreated Echeuma spinosum containing 20 g/L hexose. The highest average hydrogen production rate (HPR) of 21.58 +/- 1.59 L/L-d was observed at HRT 3 h, which was higher than previous reports for continuous H2 production from biomass feedstock. Metabolic flux analysis revealed that butyric acid and propionic acid were the major by-products of the H2-producing and H2-consuming pathways, respectively, of the algal biomass fermentation. Hydrogen consumption by propionic acid pathway could not be prevented completely by heat treatment. PICRUSt2 analysis predicted that Clostridium sp., Anaerostipes sp., and Caproiciproducens sp. might significantly contribute to the expression of both ferredoxin hydrogenase and propionate CoA-transferase. This study would provide the design and operational information on high-rate bioreactor for continuous hydrogen production using biomass.

关键词： adrenaline model   bioreactors   furostanol-type glycosides   hyperglycemia   plant cell culture   streptozotocin-induced type 2 diabetes mellitus  

摘要： In the present study, we explored the therapeutic potential of bioreactor-grown cell cultures of the medicinal plant species Dioscorea deltoidea, Tribulus terrestris and Panax japonicus to treat carbohydrate metabolism disorders (CMDs) in laboratory rats. In the adrenaline model of hyperglycemia, aqueous suspensions of cell biomass pre-administered at a dose of 100 mg dry biomass/kg significantly reduced glucose level in animal blood 1-2.5 h (D. deltoidea and T. terrestris) or 1 h (P. japonicus) after adrenaline hydrochloride administration. In a streptozotocin-induced model of type 2 diabetes mellitus, the cell biomass of D. deltoidea and T. terrestris acted towards normalization of carbohydrate and lipid metabolism, as evidenced by a significant reduction of daily diuresis (by 39-57%), blood-glucose level (by 46-51%), blood content in urine (by 78-80%) and total cholesterol (25-36%) compared to animals without treatment. Bioactive secondary metabolites identified in the cell cultures and potentially responsible for their actions were deltoside, 25(S)-protodioscin and protodioscin in D. deltoidea;furostanol-type steroidal glycosides and quinic acid derivatives in T. terrestris;and ginsenosides and malonyl-ginsenosides in P. japonicus. These results evidenced for high potential of bioreactor-grown cell suspensions of these species for prevention and treatment of CMD, which requires further investigation.

关键词： metabolic uncoupler   nitrophenols   excess sludge   nitrification and denitrification inhibition   Tetrasphaera  

摘要： In this work, the metabolic uncoupler para-nitrophenol (pNP) was applied to suppress excess sludge production and to investigate its effects on the system's performance and activated sludge community structure. The COD removal efficiency decreased from 99.0% to 89.5% prior to and after pNP addition, respectively. Application of pNP transiently reduced NH4+-N, NO3--N and NO2--N removal efficiencies, suggesting partial inhibition of both nitrifying and denitrifying activity. However, no changes in the relative abundance of the nitrifying bacteria occurred. Phosphorus removal efficiency was sharply reduced after pNP addition, as the consequence of hydrolysis of stored cell reserves. Tetrasphaera, a key polyphosphate accumulating organism, was also affected by the addition of pNP, a fact that highly influenced system's ability to remove phosphorus. A drastic drop in Soluble Microbial Products (SMP) and Extracellular Polymeric Substances (EPS) was also detected shortly after the introduction of the uncoupler. On the other hand, MBR's physicochemical parameters were restored to initial values a week after the addition of pNP. Moreover, remarkable changes in beta-diversity were noted after pNP addition. An increase of Bacteroidetes, Gammaproteobacteria and Firmicutes over Actinobacteria and Alphaproteobacteria was also observed after pNP addition.

关键词： Free cell bioreactor   In situ fibrous bed bioreactor   Recombinant protein   Sugarcane bagasse   Yarrowia lipolytica  

摘要： In this study, the ability of Yarrowia lipolytica to produce the recombinant lipase CalB from Candida antarctica, used as a model protein has been compared across different bioreactor processes using glycerol, a byproduct from the biodiesel industry as the main carbon source. Batch, pulsed fed-batch (PFB), and continuous fed-batch (CFB) strategies were first compared using classical stirred tank (STR) bioreactors in terms of biomass production, carbon source uptake, and lipase production. Additionally, an in situ fibrous bed bioreactor (isFBB) was developed using sugarcane bagasse as a cell immobilization support. The maximum lipase titer achieved using the isFBB culture mode was 38%, 33%, and 49% higher than those obtained using the batch, PFB, and CFB cultures, respectively. The lipase productivity in isFBB mode (142 U/mL/h) was 1.4-fold higher than that ob-tained using batch free cell cultures. These results highlight that isFBB is an efficient technology for the pro-duction of recombinant enzymes.

关键词： wastewater   phenol and p-cresol mixture biodegradation   bioreactor model   SKIP kinetics   discrete delay   equilibrium points   stability analysis   Hopf bifurcations   numerical simulation  

摘要： This paper is devoted to a mathematical model for phenol and p-cresol mixture degradation in a continuously stirred bioreactor. The biomass specific growth rate is presented as sum kinetics with interaction parameters (SKIP). A discrete time delay is introduced and incorporated into the biomass growth response. These two aspects-the mutual influence of the two substrates and the natural biological time delay in the biomass growth rate-are new in the scientific literature concerning bioreactor (chemostat) models. The equilibrium points of the model are determined and their local asymptotic stability as well as the occurrence of local Hopf bifurcations are studied in dependence on the delay parameter. The existence and uniqueness of positive solutions are established, and the global stabilizability of the model dynamics is proved for certain values of the delay. Numerical simulations illustrate the global behavior of the model solutions as well as the transient oscillations as a result of the Hopf bifurcation. The performed theoretical analysis and computer simulations can be successfully used to better understand the biodegradation dynamics of the chemical compounds in the bioreactor and to predict and control the system behavior in real life conditions.