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关键词： Cornstalk hydrolysates   expanded bed adsorption bioreactor   fed-batch fermentation   propionic acid   vitamin B12  

摘要： Vitamin B12 and propionic acid that were simultaneous produced by Propionibacterium freudenreichii are both favorable chemicals widely used in food preservatives, medicine, and nutrition. While the carbon source and propionic acid accumulation reflected fermentation efficiency. In this study, using corn stalk as a carbon source and fed-batch fermentation process in an expanded bed adsorption bioreactor was studied for efficient and economic biosynthesis of acid vitamin B12 and propionic. With liquid hot water pretreated corn stalk hydrolysates as carbon source, 28.65 mg L-1 of vitamin B12 and 17.05 g L-1 of propionic acid were attained at 168 h in batch fermentation. In order to optimize the fermentation outcomes, fed-batch fermentation was performed with hydrolyzed corn stalk in expanded bed adsorption bioreactor (EBAB), giving 47.6 mg L-1 vitamin B12 and 91.4 g L-1 of propionic acid at 258 h, which correspond to product yields of 0.37 mg g(-1) and 0.75 g g(-1), respectively. The present study provided a promising strategy for economically sustainable production of vitamin B12 and propionic acid by P. freudenreichii fermentation using biomass cornstalk as carbon source and expanded bed adsorption bioreactor.

关键词： 工业废水   膜生物反应器   膜污染控制  

摘要： 膜生物反应器,因性能优势应用于多种工业废水处理或回收利用。膜污染问题是影响其处理效率和推广应用的主要因素。为解决工业废水处理中的膜污染问题,通过分析膜污染形成机理,研究膜污染产生因素,针对性地提出了膜污染控制技术措施。最后,对膜生物反应器的热点研究和应用方向进行了讨论。

关键词： Separation science   Nitrogen   Anions   Bacteria   Cations  

摘要： This study developed an innovative process for the treatment of low-ammonium wastewater in a single-stage bioreactor over 250 days. Partial nitritationanammox and partial denitritation-anammox (PN/A-PDN/A) processes were combined under aerobic/anoxic operation, and a high nitrogen removal efficiency (94.6%) was obtained at a nitrogen removal rate of 0.54 kg N m(-3) d(-1) and a chemical oxygen demand to total inorganic nitrogen (COD/TIN) ratio of 0.28. Mass balance analysis identified anammox as the dominant nitrogen removal pathway, achieving 88.3% nitrogen loss. The abundance of anammox bacteria and their bioactivity rapidly increased and were effectively maintained, as indicated by qPCR and bioactivity tests. The PN/A-PDN/A process provided two pathways of nitrite production for anammox, which favored the enrichment of anammox bacteria and stable processing. In addition, the enrichment of anammox bacteria was promoted by selective floc discharge since anammox bacteria are mainly located in granules (relative abundance of 29.64 +/- 7.89%). Competitive organisms (including heterotrophic bacteria and nitrite oxidizing bacteria), enriched in flocs, were washed out. Overall, these findings confirmed anammox, sequentially combined with PN and PDN via aerobic/anoxic strategy, as a promising alternative for mainstream anammox.

关键词： Anaerobic membrane bioreactor (AnMBR)   Life cycle assessment   Domestic wastewater treatment   Nutrient and sulfide removal   Dissolved methane   Life cycle cost analysis  

摘要： The use of the anaerobic membrane bioreactor (AnMBR) process for domestic wastewater treatment presents an opportunity to mitigate environmental, social, and economic impacts currently incurred from energy-intensive conventional aerobic activated sludge processes. Previous studies have performed detailed evaluations on improving AnMBR process subcomponents to maximize energy recovery and dissolved methane recovery. Few studies have broadly evaluated the role of chemical use, membrane fouling management, and dissolved methane removal technologies. A life cycle assessment was conducted to holistically compare multiple AnMBR-based domestic wastewater treatment trains to conventional activated sludge (CAS) treatment. These treatment trains included different scouring methods to mitigate membrane fouling (gas-sparging and granular activated carbon-fluidizing) with consideration of upstream treatment (primary sedimentation vs. screening only), downstream treatment (dissolved methane removal and nutrient removal) and sludge management (anaerobic digestion and lime stabilization). This study determined two process subcomponents (sulfide and phosphorus removal and sludge management) that drove chemical use and residuals generation, and in turn the environmental and cost impacts. Furthermore, integrating primary sedimentation and a vacuum degassing tank for dissolved methane removal maximized net energy recovery. Sustainability impacts were further mitigated by operating at a higher flux and temperature, as well as by substituting biological sulfide removal for chemical coagulation.

关键词： 生物反应器   接种疫苗   纳瓦拉   两层楼   首席执行官   阿达尔   玻璃瓶  

摘要： 首席执行官阿达尔·波纳瓦拉(Adar Poonawalla)执掌的印度血清研究所(Serum Institute of India)是全球最大的疫苗供应商,每年能生产约15亿剂人体接种疫苗,几乎涵盖各个门类。该公司拥有的设备每分钟能灌装500支小玻璃瓶,数座闪闪发光、接近两层楼高的钢质生物反应器每个月能生成超过1000万剂疫苗的药液。他可以令人信服地宣称,他为分布在100多个国家和地区的全世界65%的儿童预防麻疹和肺结核等疾病做出了贡献。

关键词： 陶瓷平板膜   MBR反应器   煤化工废水  

摘要： 煤化工废水具有水量大和生物毒性高的特性,结合MBR高污泥浓度和陶瓷平板膜良好的抗有机物污染性能,使用浸没式陶瓷平板膜生物反应器处理粗酚模拟配制的煤化工废水,结果表明COD、氨氮和总酚的去除率分别达到94.91%、96.60%、97.92%以上。跨膜压差在曝气量为200 mL/min,抽停比为9:1时运行66 d达到40 kPa。对细菌群落结构分析发现,膜片上的生物群落较混合液中更加丰富,膜组件的加入提高了反应器中的物种多样性。

关键词： 光机电一体化   生物反应器   长春理工大学   光电检测   光学成像   原位检测   肿瘤基因   图像处理软件  

摘要： 为满足医药企业自主创新需求,利用生物反应器开发生物疫苗制备新工艺、开发临床肿瘤基因精准诊断技术,以及需要配套的光电显微成像原位检测分析设备,长春理工大学发挥光电优势,利用生物技术与光机电一体化集成创新研究,研制了系列长工作距、高分辨率、扫描成像光电检测分析新设备及图像处理软件,促进了疫苗行业和基因诊断领域技术进步.

关键词： bioaugmentation   biostimulation   dissimilatory nitrate reduction to ammonium   denitrification   woodchip bioreactor  

摘要： Aims This study was done to obtain denitrifiers that could be used for bioaugmentation in woodchip bioreactors to remove nitrate from agricultural subsurface drainage water. Methods and Results We isolated denitrifiers from four different bioreactors in Minnesota, and characterized the strains by measuring their denitrification rates and analysing their whole genomes. A total of 206 bacteria were isolated from woodchips and thick biofilms (bioslimes) that formed in the bioreactors, 76 of which were able to reduce nitrate at 15 degrees C. Among those, nine potential denitrifying strains were identified, all of which were isolated from the woodchip samples. Although many nitrate-reducing strains were isolated from the bioslime samples, none were categorized as denitrifiers but instead as carrying out dissimilatory nitrate reduction to ammonium. Conclusions Among the denitrifiers confirmed by N-15 stable isotope analysis and genome analysis, Cellulomonas cellasea strain WB94 and Microvirgula aerodenitrificans strain BE2.4 appear to be promising for bioreactor bioaugmentation due to their potential for both aerobic and anaerobic denitrification, and the ability of strain WB94 to degrade cellulose. Significance and Impact of the Study Denitrifiers isolated in this study could be useful for bioaugmentation application to enhance nitrate removal in woodchip bioreactors.

关键词： Pharmaceuticals and personal care products (PPCPs)   Electrochemical advanced oxidation   Membrane bioreactor   Biological degradation   Wastewater treatment  

摘要： A novel electrochemical membrane bioreactor (EMBR) was developed for enhancing PPCPs removal from real municipal wastewater. Compared to the control MBR (CMBR) without applying electric field, EMBR exhibited higher removal efficiencies for 14 PPCPs among all investigated PPCPs, including 3 fluoroquinolones, 2 macrolides, 6 sulfonamides and 3 anti-inflammatory drugs, while no significant difference was observed for the rest 8 PPCPs. The enhanced removal of 14 PPCPs was mainly attributed to electrooxidation by the direct anodic oxidation and reactive oxygen species-mediated indirect oxidation. Moreover, membrane fouling rates of EMBR (0.55 +/- 0.10 kPa/d) were significantly reduced compared with CMBR (0.99 +/- 0.09 kPa/d). Microbial activities and community analyses demonstrated that the applied electric field had no noticeable adverse impact on microbial viabilities, richness and diversity. These findings demonstrated that this EMBR enhanced pollutant removal and mitigated membrane fouling simultaneously, highlighting the potential of the novel technology to be used for removing PPCPs from wastewater.

关键词： Fixed Bed   Downstream   Cellulolytic Enzymes   Bioethanol   Biorefineries  

摘要： Cellulases are enzymes required for the production of second-generation ethanol (E2G) via biochemical route. The current paper reports the development of an apparatus for solid-liquid extraction of cellulases from solid-state fermentation (SSF) carried out in a packed bed bioreactor (PBB), operated as batch and as semicontinuous. The case study was the cultivation ofMyceliophthora thermophilaI-1D3b on sugarcane bagasse (SCB) and wheat bran (WB) (7: 3 w/w). The current work integrates the PBB to the first downstream step for recovering the enzymes produced by SSF. The substrate was inoculated and packed into the modules that composed the PBB. The fermentation occurred at 45 degrees C and air was supplied with flow rate of 350 L/h. At the end of the cultivations, each module was placed in an extraction column, a dynamic closed system in which distilled water was circulated and made to percolate the cultivated material. Variables tested were volume of water per mass of substrate, water flow rate and time of percolation. Higher contact time (120 min) and higher flow rate (2.4m(3)/h) allowed us to recover up to 85% of total enzyme activity by percolation. Lower volume (20mL/g) provides higher titer extract. The apparatus showed to be promising for SSF downstream, mainly for semicontinuous operation of PPBs.