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关键词： Hybrid fixed-bed bioreactor   Fe-modified zeolite   Biohydrogen   Trace metal   Microorganism nutrition carrier (MNC)  

摘要： In this study, we describe the development of a hybrid bioreactor with integrated chlorinated polyethylene (CPE) fixed-bed and zeolite as a microorganism nutrition carrier (MNC), aiming at enhancing and sustaining biohydrogen production during the anaerobic digestion (AD) process. In the batch test, the hybrid bioreactor achieved a maximumbiohydrogen production of 646.3 mL/L. Accordingly, the hybrid bioreactor significantly enhanced biohydrogen production and maintained a stable performance for 50 days of semi-continuous operation. This result should be attributed to the CPE providing roughness surface and high porosity for microorganism immobilization, resulting in the enhancement of microbial quantity, confirmed by our scanning electron microscope and immobilized biomass analyses. Moreover, the element ratio significantly decreased, indicating that zeolite could provide metal cations for stimulating microbial bioactivity and growth, as well as contributing to superior biohydrogen productivity during the 50-day operation. In order to further enhance and sustain long-term biohydrogen production, raw zeolite was modified with iron. The hybrid-Fe bioreactor (CPE with Fe-modified zeolite) operated mainly following the acetate pathway and exhibited higher sustainability in improving biohydrogen production with a peak value of 1893.0 mL/L during a 72-day-lasting operation. The synergistic mechanismof the Fe-modified zeolite and CPE fixed-bed revealed that it could effectively induce favorable pathways and contribute to the synthesis of essential enzymes, micronutrient supplementation, electoral conductivity, and microbial immobilization for biohydrogen production. Therefore, a hybrid-Fe bioreactor could provide a unique alternative for the enhancement of hydrogen production for practical applications. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 膜生物反应器   污水处理   膜分离   生物处理  

摘要： 膜生物反应器是将膜分离技术与生物处理单元相结合的新型污水处理技术,在污水处理领域中得到了广泛的应用。本文综述了膜生物反应器技术研究现状及行业应用情况,解析了影响膜生物反应器处理性能的相关因素,指出了目前存在的问题,展望了膜生物反应器的应用前景。

关键词： 嗜盐微生物   下一代工业生物技术   聚羟基脂肪酸酯   合成生物学   生物反应器   聚合物  

摘要： 嗜盐微生物是一种耐高盐的微生物,有细菌、古菌、藻类等。其中的中度嗜盐菌耐受30~150g/L的氯化钠,有很高的研究价值和应用前景。嗜盐微生物可以在海水中生长,有的同时嗜碱,尤其不少嗜盐细菌在矿物培养基中生长迅速,具有作为底盘细胞的优势。随着近年来对嗜盐微生物分子操作工具的不断开发,嗜盐细菌的改造工作得到了迅猛发展。工程化的嗜盐微生物已经可以用于合成数种聚羟基脂肪酸酯(PHA),也用于大规模生产多种聚合物、蛋白质、小分子化合物、氨基酸和化妆品原料。合成生物学技术的使用也使嗜盐微生物实现了可控形变,有利于更多的胞内产物的合成和下游的细胞分离。根据嗜盐微生物,特别是嗜盐细菌的特点和研究进展,本文提出了以嗜盐微生物作为底盘细胞的“下一代工业生物技术”,使发酵工业实现开放式的节能、节水、连续、全自动的过程,减少微生物大规模培养的复杂程度和对设备的高要求,同时能联产生产多种产品,大幅度降低工业生物技术的制造成本,提高产品的竞争性。

关键词： Hollow-fiber membrane bioreactor   Antibiotics   Penicillium restrictum   Biofouling   Quorum quenching  

摘要： The effects of bioaugmentation with immobilized Penicillium restrictum on the removal efficiency of sulfamethoxazole (SMX), erythromycin (ERY) and tetracycline (TC) antibiotics as well as membrane biofouling was studied using hollow-fiber membrane bioreactor (HF-MBR). Bioaugmentation with P. restrictum led to a significant change in the antibiotic removal efficiency and relative abundance of aerobic microbial community, most probably as a result of its quorum quenching activity. Furthermore, in addition to its role in the increase of SMX and ERY removal efficiencies and the decrease of their sorption on solid phase, bioaugmentation significantly reduced the transmembrane pressure which in turn reduced membrane clogging. The most abundant phyla in sludge and biofilm samples in the presence of P. restrictum were observed to be Proteobacteria, Bacteroidetes and Firmicutes. Differences in bacterial compositions and their specificity in biodegradation of antibiotics in different reactors showed that bacteria were specifically selected under the pressure of antibiotics and growing fungus.

关键词： 特种经济动物   水生生物资源   水产养殖   专任教师   国家重点学科   生物反应器   现代生物技术   正高职称  

摘要： 特种经济动物科学系,包含蚕学、蜂学、水产养殖等三个专业,是特种经济动物饲养(含:蚕、蜂等)国家重点学科所在系,也是“211工程”重点建设单位。现有专任教师23人,具有正高职称14人,具有博士招生资格教师15人,副高职称9人。研究方向以现代生物技术为主要手段,以蚕、蜂和水产经济动物为主要研究对象,已形成了五个主要研究方向:①种质资源与分子育种;②生物机能与病害控制;③生物反应器与基因工程;④生物资源与材料工程;⑤水生生物资源与水产养殖。

关键词： Sludge yield reduction   Anoxic bioreactor   Sludge interchange rate   Membrane bioreactor   Wastewater  

摘要： While cleaning wastewater, biological wastewater treatment processes such as membrane bioreactors (MBR) produce a significant amount of sludge that requires costly management. In the oxic-settling-anoxic (OSA) process, sludge is retained for a temporary period in side-stream reactors with low oxygen and substrate, and then it is recirculated to the main reactor. In this way, excess sludge production is reduced. We studied the influence of the rate of sludge exchange between MBR and side-stream anoxic reactors on sludge yield reduction within MBR. Two MBRs, namely, MBROSA and MBRcontrol, each coupled with separate external anoxic side-stream reactors, were run in parallel for 350 days. Unlike MBRcontrol, MBROSA had sludge exchange with the external reactors connected to it. During the investigation over a sludge interchange rate (SIR) range of 0-22%, an SIR of 11% achieved the highest sludge reduction (58%). Greater volatile solids destruction i.e., bacterial cell lysis and extracellular polymeric substance (EPS) destruction occurred at the SIR of 11%, which helped to achieve the highest sludge reduction. The enhanced volatile solids destruction was evident by the release of nutrients in the external anoxic reactors. It was confirmed that the sludge yield reduction was achieved without compromising the wastewater treatment quality, sludge settleability and hydraulic performance of the membrane in MBR.

关键词： 海洋微藻   光合反应器   连续培养  

摘要： 本试验采用连续式微藻培养系统(包括封闭式光合反应器和连续式水处理器)对小球藻、新月菱形藻和湛江叉鞭金藻的生长情况进行研究。结果表明:在连续培养状态下,每日收获60~80L藻液,可使反应器内保持较高密度,该反应器具有稳定生产微藻能力。

关键词： Chemical scrubber   Modular biofilter   Odour pollution abatement   Wastewater treatment plants   Feasibility  

摘要： Chemical scrubbing and biofiltration are well-established technologies for treating contaminated pollutants generated at wastewater treatment plants (WWTPs). Nevertheless, the growing need to reduce the ecological footprint of abatement technologies without affecting process efficiency is prioritizing biological alternatives. This study deals with the challenge of designing a structure for converting a chemical scrubber currently operating at a WWTP with a capacity of 6400 population equivalent (PE) into a modular bioreactor without any actual modification of the scrubber's structure. The inside of the reactor was divided into three levels or platforms for holding the biomaterial, and the corresponding parts were manufactured in PVC, with the exceptions of the screws and cross bracing. The study of the parts' stress and strain limits revealed that the slats and half-rings should be reinforced with ribs, and the optimal rib height was studied on a case-by-case basis. It was also concluded that the base legs could hold the weight of 80 cm height biomaterial bed onto each of the three platforms. Based on previous studies, the converted biofilter with an inlet flow rate of 1150 m(3)/11 could render simultaneous removal efficiencies greater than 90 % for H-2 S and NH3. Regarding the viability study, the annual savings from the elimination of chemical consumption were around 9.7 % of the total investment cost. One of the main strengths of replacing the scrubber with a biofilter was the improvement in sustainable performance and health and safety, reducing both risk and the budget for prevention. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Methane bioconversion   Bioreactor design   Biocover system   Biogas   Wastewater treatment  

摘要： Global methane emissions have been steadily increasing over the past few decades, exerting a negative effect on the environment. Biogas from landfills and sewage treatment plants is the main anthropogenic source of methane. This makes methane bioconversion one of the priority areas of biotechnology. This process involves the production of biochemical compounds from non-food sources through microbiological synthesis. Methanotrophic bacteria are a promising tool for methane bioconversion due to their ability to use this greenhouse gas and to produce protein-rich biomass, as well as a broad range of useful organic compounds. Currently, methane is used not only to produce biomass and chemical compounds, but also to increase the efficiency of water and solid waste treatment. However, the use of gaseous substrates in biotechnological processes is associated with some difficulties. The low solubility of methane in water is one of the major problems. Different approaches have been involved to encounter these challenges, including different bioreactor and gas distribution designs, solid carriers and bulk sorbents, as well as varying air/oxygen supply, the ratio of volumetric flow rate of gas mixture to its consumption rate, etc. The aim of this review was to summarize the current data on different bioreactor designs and the aspects of their applications for methane bioconversion and wastewater treatment. The bioreactors used in these processes must meet a number of requirements such as low methane emission, improved gas exchange surface, and controlled substrate supply to the reaction zone.

关键词： Baffled bioreactor   CFD simulation   Flow field   Oxygen transfer   Shear environment  

摘要： Disposable orbitally shaken bioreactors have been widely used for mammalian cell culture in suspension. Three kinds of baffle structures: vertical baffle, inclined baffle and horizontal baffle were designed in this work. The flow fields of the shaking bioreactor with different baffle structures were simulated, and the turbulence, dissolved oxygen and shear strain rate of the bioreactor were analyzed. The results showed that the quasi-steady-state flow patterns of the unbaffled shaking bioreactors were broken for the bioreactors with the strengthening effects of baffles. The mixing and the oxygen volumetric mass transfer coefficient (k(L)a) (simulated results) were improved significantly, and the shear strain rates were also increased greatly for the baffle bioreactors. The shear strain rates of the baffle bioreactors were mainly in the range of 0-20 s(-1), and they were still low enough for CHO cell cultures.