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关键词： Electroconductive moving bed membrane bioreactor (EcMB-MBR)   Floating conductive media   Energy reduction   Hybrid bio-electrochemical denitrification   Membrane fouling control   Decentralized wastewater treatment  

摘要： Membrane bioreactor (MBR) is an advantageous technology for wastewater treatment. However, efficient nutrient removal and membrane fouling mitigation remain major challenges in its applications. In this study, an electroconductive moving bed membrane bioreactor (EcMB-MBR) was proposed for simultaneous removal of organics and nutrients from domestic wastewater. The EcMB-MBR was composed of a submerged MBR, filled with electrodes and free-floating conductive media. Conductive media were introduced to reduce energy consumption in an electrochemical MBR, to improve nitrogen removal, and to mitigate membrane fouling. The results showed that COD, total nitrogen, and total phosphorus removal was up to 97.1 +/- 1.4%, 88.8 +/- 4.2%, and 99.0 +/- 0.9%, respectively, in comparison with those of 93.4 +/- 1.5%, 65.2 +/- 5.3%, and 20.4 +/- 11.3% in a conventional submerged MBR. Meanwhile, a total membrane resistance reduction of 26.7% was obtained in the EcMB-MBR. The optimized operating condition was determined at an intermittent electricity exposure time of 10 min-ON/10 min-OFF, and a direct current density of 15 A/m(2). The interactions between electric current and conductive media were explored to understand the working mechanism in this proposed system. The conductive media reduced 21% of the electrical resistivity in the mixed liquor at a selected packing density of 0.20 (v/v). The combination of electrochemical process and conductive media specially enhanced the reduction of nitrate-nitrogen (NO3--N) through hybrid bio-electrochemical denitrification processes. These mechanisms involved with electrochemically assisted autotrophic denitrification by autotrophic denitrifying bacteria. As a result, 5.2% of NO3--N remained in the effluent of EcMB-MBR in comparison with that of 29.5% in the MBR. Membrane fouling was minimized via both mechanical scouring and electrochemical decomposition/precipitation of organic/particulate foulants. Furthermore, a preliminary cost analysis ind

关键词： Anaerobic digestion   Anaerobic membrane bioreactor (AnMBR)   Forward osmosis (FO)   Water resource recovery facility (WRRF)   Municipal sewage treatment   Sodium inhibition  

摘要： This research evaluated the performance of a lab-scale anaerobic membrane bioreactor (AnMBR) treatingmunicipal sewage pre-concentrated by forward osmosis (FO). The organic loading rate (OLR) and sodium concentrations of the synthetic sewage stepwise increased from 0.3 to 2.0 g COD L-1 d(-1) and from 0.28 to 2.30 g Na+ L-1 to simulate pre-concentration factors of 1, 2, 5 and 10. Nomajor operational problemswere observed during AnMBR operation, with COD removal efficiencies ranging between 90 and 96%. The methane yield progressively increased from 214 +/- 79 to 322 +/- 60 mL CH4 g(-1) COD as the pre-concentration factor increased from 1 to 10. This wasmainly attributed to the lower fraction ofmethane dissolved lost in the permeate at higher OLRs. Interestingly, at the highest pre-concentration factor (2.30 g Na+ L-1) the difference between the permeate and the digester soluble COD indicated that membrane biofilm also played a role in COD removal. Finally, a preliminary energy and economic analysis showed that, at a pre-concentration factor of 10, the AnMBR temperature could be increased 10 degrees C and achieve a positive net present value (NPV) of 4 M(sic) for a newly constructed AnMBR treating 10,000 m(3) d(-1) of pre-concentrated sewage with an AnMBR lifetime of 20 years. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 老龄垃圾渗滤液   生物反应床   难降解生物源废物填料   脱氮  

摘要： 渗滤液具有成分复杂、含盐量高、毒性大等特点,如果直接排放会对周围环境造成严重危害,生物处理因其成本低,是目前主要处理技术。基于生物反应床工艺,将生活垃圾转运废弃集装箱改制为生物反应床体,以废旧织物、动物骨料、泡沫混凝土、矿化垃圾等难降解生活源废物为填料,用于预处理渗滤液,当进水量为1400 L/d时,对老龄渗滤液COD去除率在40%以上,总氮去除率稳定在80%左右。该装置系统简单、成本低且无需复杂维护,同时对调节池总氮具有显著的去除效果,应用前景良好。

关键词： Submerged osmotic membrane bioreactor   Aerobic granule   Membrane fouling   Water flux   Microbial diversity  

摘要： Forward osmotic membrane bioreactors (FOMBRs) have broad prospects for application in wastewater reuse and resource recovery. Problems such as concentration polarization, salinity accumulation, and membrane fouling have led to a rapid flux decline, which limit their practical application. In this study, we introduced aerobic granules into a FOMBR to clarify the effect of sludge morphology on reactor performance. The results showed that the average removal efficiency of total organic carbon (TOC) and phosphate-phosphorus (PO43--P) were maintained above 95% during the operation of activated sludge-based FOMBR (R1) and aerobic granule-based FOMBR (R2), respectively. R2 achieved higher removal efficiency of ammonia-nitrogen (NH4+-N) with an average removal efficiency of 77%, which was significantly higher than R1 (57%). Over the entire operation, the content of the soluble microbial products (SMP) in R1 was generally higher than that in R2, which resulted in more polysaccharides and proteins in the fouling layer of the membrane. The membrane flux of R2 was 1.0 L.m(-2).h(-1) higher than that of R1. The average size of flocs in R1 decreased from 137.24 mu m to 76.84 mu m, and that of the aerobic granules in R2 decreased from 2.35 mm to 1.20 mm and then remained stable. The results of microbial analysis showed that the membrane surface had lower microbial diversity than that of the mixed liquid, and the microorganisms enriched at the membrane surface were mainly Proteobacteria and Firmicutes with better salt tolerance.

关键词： 生猪养殖废水   序批式膜生物反应器   A2/O   生物脱氮   温度  

摘要： 针对生猪养殖废水处理过程中普遍存在的脱氮效果不佳,工艺流程较长等问题,采用中试规模序批式膜生物反应器(SMBR)处理生猪养殖废水,并与猪场现有废水处理A^(2)/O工艺进行了比较。结果表明:SMBR在运行温度逐步降低的情况下,可以取得较好的污染物去除效果,氨氮平均出水浓度为10 mg·L^(-1),去除率达到98.6%;总氮平均出水浓度为31 mg·L^(-1),去除率达到96.5%;COD为332 mg·L^(-1),去除率达到96.5%。猪场现有A^(2)/O工艺对氨氮、总氮和耗氧有机物的去除率分别为99%、88%和97%。高通量测序和OUT分类结果表明,SMBR中主要的AOB为Nitrosomonas,NOB主要为Nitrospira、Nitrobacter和Nitrolancea。AOB是SMBR主要的硝化细菌,NOB是A^(2)/O工艺中主要的硝化细菌,并且反硝化细菌在SMBR中的菌群丰度高于A^(2)/O工艺中的反硝化菌群丰度。综上所述,与A^(2)/O工艺相比,SMBR具有短流程和脱氮效果较好等优势,这可使其具有较好的应用前景。

关键词： Cell separation   Mini-hydrocyclone   Spiral microchannel   Mammalian cells   Microfiltration   Inertial microfluidics  

摘要： Large-scale cell culture processes are required to produce biopharmaceuticals, cells for tissue engineering, and vaccine production while being effective in toxicity testing, gene therapy vector production for cancer research, and drug development. A growing trend in these industries, particularly for suspension cells, involves implementation of continuous cell perfusion processes, which require an aseptic, efficient, cost-effective, and reliable cell separation and retention scheme. Many cell separation techniques (membrane-based systems, lateral displacement devices, and acoustophoresis) have proven to be highly efficient, but suffer from issue of clogging and high cost, limiting their reliability, and thus, their overall feasibility. Some cell retention devices-those based on inertial microfluidics-offer high reliability (i.e., clog-free), but their efficiency reduces at higher cell concentrations. To overcome this apparent trade-off, we report the development of an integrated system consisting of two different membrane-less microfiltration techniques for cell separation from spent cell media. Although it could be adapted to numerous cell culture applications, this system was optimized and tested for suspension-adapted Chinese Hamster Ovary (CHO) cells. As the first step of the cell retention system, a miniaturised hydrocyclone was developed that could separate the cells with macroscopic volume processing rates (similar to 200 mL/min). At this stage, up to 75% of the cells were isolated with minimal (< 5%) change in the viability. The remaining cells passed through the overflow of the device and entered to a multiplexed spiral microchannel system, where more than 90% of the remaining cells were recovered, yielding an overall efficiency of up to 95%. The proposed integrated system is thus ideal for continuous and high throughput cell retention even at high cell concentrations (similar to 80 million cells/mL), which is in range of current need in the bioprocessing

关键词： 骨肉瘤   白花丹素   MG-63细胞   基质金属蛋白酶   凋亡   迁移  

摘要： 目的:研究不同浓度白花丹素对骨肉瘤细胞MG-63凋亡迁移、基质金属蛋白酶(MMP)及Bcl-2、Bax、Ezrin蛋白表达的影响。方法:取对数生长期的骨肉瘤MG-63细胞,传代培养成细胞株后以随机法分成对照组、低剂量组、中剂量组、高剂量组。其中对照组加入到0.1%浓度的DMSO完全培养基中培养,低剂量组、中剂量组、高剂量组分别加入到浓度为5、10、20μmol/L的白花丹素的有关培养基中培养。培养24 h后,采用Transwell法检测MG-63细胞迁移率、Hoechst33342染色法检测MG-63细胞凋亡率、Western blot法检测四组MG-63细胞的MMP-2、MMP-9、Bcl-2、Bax、Ezrin蛋白表达水平。结果:培养24 h后,低剂量组、中剂量组、高剂量组的骨肉瘤细胞MG-63凋亡率及Bax蛋白表达水平均较对照组升高(P<0.05),且随白花丹素浓度的增加而升高(P<0.05);骨肉瘤细胞MG-63的细胞迁移率、MMP-2、MMP-9、Bcl-2及Ezrin蛋白表达水平较对照组降低(P<0.05),且随白花丹素浓度的增加而降低(P<0.05)。结论:白花丹素对骨肉瘤细胞MG-63凋亡的促进作用以及迁移的抑制作用明显,其作用机制可能与抑制骨肉瘤细胞MG-63中的MMP-2、MMP-9、Bcl-2、Ezrin蛋白表达及促进Bax蛋白表达有关,且浓度越高,抑制或促进作用越明显。

关键词： Waste reuse   Low C/N wastewater   FA mitigation   Techno-economic superiority  

摘要： Reusing microplastics and zeolite waste as free ammonia (FA)-mitigating carrier particle was proven a value-added step towards promoting the serviceability of fluidized bed bioreactor (FBBR) in treating wastewater with a lowcarbon to nitrogen ratio (i.e. C/N<3.0) in this study. Ammonia (NH4+) adsorption property capacitates zeolite as an FA mitigator. The microplastics and reused zeolite were processed into reused-zeolite/microplastic composite particle (RZ), whosemerit of FA mitigation was fully developed via an optimally thermal modification to process modified-zeolite/microplastic particle (MZ). The 171-day biological nutrient removal (BNR) performance in a single integrated fluidized bed bioreactor (SIFBBR) shows that the bioreactor with MZ particle (SIFBBR-MZ) achieved nitrogen removal efficiency 10.0% higher than the bioreactor with RZ particle (SIFBBR-RZ) over the enhanced short-cut nitrification and denitrification. Analysis ofmicrobial community structure unveils that the long-term lower FA inhibition favored more significant ammonia-oxidizing bacteria (AOB) enrichment and acclimated specific MZ biofilm predominant by nitrite (NO2-) denitrifier, contributing to the outperformance in nitrogen removal. Apart fromfluidization energy conservation, the techno-economic analysis confirms that using MZ as an FA-mitigating carrier could be of great benefit for FBBR system: realizing waste utilization, reducing carbon addition and alleviating sludge treatment. (C) 2020 Published by Elsevier B.V.

关键词： Odors   Combined bioreactor   Biological aeration zone   Biological filtration zone   Aerosols  

摘要： A full-scale combined bioreactor with a biological aeration zone (BAZ) and a biological filtration zone (BFZ) was adopted to treat odors, volatile organic compounds (VOCs), and aerosols emitted from a landfill site. The BAZ mainly relies on suspended microorganisms that degrade substances with high water solubility, while the BFZ is divided into an acidic biofiltration unit (ABU) and a neutral biofiltration unit (NBU) to further remove remaining contaminants. Average removal efficiencies (REs) of 97.21%, 98.89%, 92.44%, 73.12%, and 81.89% for H2S, NH3, VOCs, culturable bacteria, and fungi, respectively, were achieved during the stable operation period. In particular, the concentrations of water-soluble ions (WSIs), including SO42-, NO2-, NO3-, and Cl- in aerosols, were significantly reduced by the combined bioreactor. The REs and degradation product characteristics for the odors, VOCs, and aerosols in the BAZ and BFZ were different due to different dominant microorganisms. In addition, the economic cost of the combined bioreactor was analyzed considering investment cost, operating cost, and packing material replacement cost, and a sensitivity analysis was performed to determine economically-sensitive parameters. This study clearly demonstrates the low cost and effectiveness of the combined bioreactor to treat exhaust gases containing odors, VOCs, and aerosols from a landfill site. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： 膜生物反应器   生物制药   废水处理  

摘要： 疫苗制药工业废水属于高浓度有机废水,含有脂肪、蛋白质、氨氮等物质。废水难以降解,且水质和水量波动大,不易处理。膜生物反应器(MBR)是将高效膜分离技术与传统活性污泥法相结合的一种新型高效污水处理技术。采用结构独特的浸入式膜模块,放置在曝气池内。废水经过好氧曝气和生物处理后,由泵通过滤膜过滤后提取。