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1.
The spatial distribution of extracellular polymeric substances （EPS） in a pilot-scale membrane bioreactor （MBR） was studied. The sampling points on top of and inside the membrane module were measured and analyzed by the experimental variant function. The content of EPS was spatially interpolated by ordinary Kriging method, and il- lustrated with SURFER software. A case study was carried out in an MBR with membrane aperture of 0.4 ~tm and handling capacity of 120 ma/d in Jizhuangzi sewage treatment plant, Tianjin. From the visualization of EPS distribu- tion, it is seen that on the horizontal plane, the content of EPS was the lowest at the center; and on the vertical plane, the content of EPS decreased with the increase of depth. The shearing force caused by aeration of perforated pipe and the influent mode are the main influencing factors for this distribution. 相似文献
2.
A membrane bioreactor (MBR) was established for treating harbor oily wastewater. It showed good removal performance for chemical oxygen demand (COD), oil content, suspended solids (SS), and other pollutants. However, serious membrane fouling occurred. It was recognized that the extracellular polymeric substances (EPS) accumulated on the membrane surface, especially the proteins, were of great importance for the transmembrane pressure (TMP) increment and membrane fouling. The MBR was optimized via improving aeration rate and reducing the ratio of Ar/Ad (Ar and Ad are the cross-sectional areas of the riser and the downcomer of the MBR). The increasing rate of TMP was slowed, indicating that the optimization strategy could effectively mitigate membrane fouling. Microbial community evolution was monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), cloning, and sequencing of 16S ribosomal ribonucleic acid (rRNA) fragments. Results revealed that low community shift occurred during the whole operational period. Geobacter sp. and Rhodocyclales sp., which have also been identified by other studies in a petroleum refinery wastewater MBR or an infiltration basin receiving highway runoff, dominated in the MBR system throughout. Comamonas sp. was thought to accommodate the lower aeration rate in this study, while Rhodocyclales sp. preferred the higher aeration rate. In addition, during the operational time under high organic loading rate, a few species were present in abundance, and may have been responsible for the good removal performance at this time. 相似文献
3.
To prevent expanded polystyrene (EPS) beads from rising up to the surface in the molding process of EPS lightweight concrete, vibration with pressure was applied and the polyvinyl acetate (PVA) emulsion was adopted to im-prove its mechanical properties. The mechanical properties, thermal properties and durability of EPS lightweight concrete were tested. The microstructures of EPS lightweight concrete were observed by scanning electron microscope (SEM). Vibration with pressure reduces the number of small cracks. The 180 d compressive strength and flexural strength increase obviously as a large amount of PVA was added. The mixed amount of PVA has no obvious influence on the thermal per-formance when it is not more than 10% of the cement. Vibration with pressure and surface modification of EPS beads by PVA improve the combination of EPS beads with cement stone and the mechanical properties of EPS lightweight con-crete. 相似文献
4.
膜污染是制约膜生物反应器（MBR）工程化应用的瓶颈。针对现有MBR存在的缺点,本文提出了新型的颗粒填料复合式膜生物反应器（HMBR）,并介绍了HMBR在工业废水处理中的应用。通过分析悬浮颗粒物在膜表面的沉积条件,从流体力学、微生物学、水处理工艺学、亚微观动力学等方面对HMBR的性能和特点进行了详细阐述,表明颗粒填料可以有效地减缓膜污染和提高膜生物反应器过滤性能。 相似文献
5.
设计了膜生物反应器 (MBR)与粉末活性炭 (PAC)联合使用的膜组合工艺 (PAC MBR)处理微污染地表水 ,并用分子量分析方法来考察PAC MBR组合工艺及各单元工艺对有机物的去除效果 .分析结果表明 ,由于原水中的小分子有机物难生物降解 ,该工艺出水有机物集中在小于 1k的分子量区间内 ,活性炭的投加能显著提高这部分有机物的去除率 .试验证明 ,PAC MBR工艺中生物处理与活性炭吸附互相促进 ,在稳定运行阶段对CODMn、UV2 54 、UV4 10 和氨氮的去除率分别达到 70 %、70 %、10 0 %和 92 % . 相似文献
6.
针对某市河道黑臭水体的特性及污染物特点,采用"膜生物反应器(MBR)一体化工艺、补氧+生物膜、人工清淤"综合治理技术对其进行治理。实际治理结果表明,MBR一体化工艺出水水质达到了《城市污水再生利用景观环境用水水质》(GB/T18921-2019)的要求;补氧与生物膜的组合应用最大程度地消除了黑臭现象;采用人工清淤方式对河床内淤泥进行了全部清除,消除了内源污染;工程运行费用为70.39万元/年。该综合治理技术治理河道黑臭水体效果良好,适合在其他类似项目中推广应用。 相似文献
7.
文章给出了转动参照系平面与水平面成任意角时有质负载弹簧匀速转动情况下弹簧中的应力分布及弹簧长度的公式,根据公式编写程序,绘图直观反映弹簧自身质量m、劲度系数七、旋转角速度ω和转动参照系平面与水平面的夹角θ等因素的影响． 相似文献
8.
王昌锐 《襄樊职业技术学院学报》2004,3(6):44-46
每股收益是证券市场中最为常见的财务指标之一，许多会计报表的使用者经常依赖其作出投资决策，因为他们认为透过该数据能够评价管理当局过去的业绩，同时可以预测公司未来的收益。但过分依赖于公开的每股收益会导致许多失误，每股收益并不具有如此丰富的信息含量。 相似文献
9.
对当下医学院校的公共英语演讲课程做出了三点调整:一是将公共英语演讲课程的定位从跨文化交际类通识课逐渐过渡到专门用途英语课.二是在教学内容的选择上凸显医学学科特色;提升对思辨能力的系统性认识;增加对说理演讲的学习,达到专业、技能、思辨的深度融合.三是在教学模式上,采用线上线下混合式教学.通过上述方法并举,力求使医学院校开... 相似文献
10.
从公司利润对每股收益的决策作用这个角度，分析了公司利润在确认、计量、报告中存在的质量问题，从而揭示了每股收益信息存在的问题，进而提出解决问题的几点措施。 相似文献
11.
Berbamine induces apoptosis in human hepatoma cell line SMMC7721 by loss in mitochondrial transmembrane potential and caspase activation 总被引：14，自引：2，他引：12
Objective： To investigate the effect ofberbamine on human hepatoma cell line SMMC7721. Methods： The effects of 24 h and 48 h incubation with different concentrations （0-64 μg/ml） of the berbamine on SMMC7721 cells were evaluated using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide （MTT） assay. Hoechst 33258 staining was conducted to distinguish the apoptotic cell, and the appearance of sub-G1 stage was determined by PI （propidium iodide） staining, the percentage of apoptotic cell was determined by flow cytometry following annexin V/PI staining. Flow cytometry was performed to analyze the cell cycle distribution and the mitochondrial membrane potential （△ψm）, the expression of activated caspase3 and caspase9 was analyzed by Western-blot. Results： The proliferation of SMMC7721 was decreased after treatment with berbamine in a dose- and time-dependent manner. Berbamine could induce apoptosis in SMMC7721 cells and could cause cell cycle arrest in G0/G1 phase, to induce loss of mitochondrial membrane potential （AVm） and activate caspase3 and caspase9. Berbamine-induced apoptosis could be blocked by the broad caspase inhibitor z-VAD-fmk. Conclusion： Berbamine exerts antiproliferative effects on human hepatocellular carcinoma SMMC7721 cells. The anticancer activity of berbamine could be attributed partly to its inhibition of cell proliferation and induction of apoptosis in cancer cells through loss in mitochondrial transmembrane potential and caspase activation. 相似文献
12.
高速磁浮轨道不平顺测试及分析 总被引：2，自引：0，他引：2
研究目的：提出高速磁浮轨道不平顺处理方法,分析不平顺特征,拟合形成轨道谱,为线路卒问维护提供参考。创新要点：实现了对高速磁浮轨道不平顺的提取,确定了轨道谱参数。研究方法：基于惯性基准法,运用数字信号处理方法实现对轨道不平顺的提取,采用最小二乘法拟合得剑定子向和导向面七参数轨道谱。重要结论：定子面和导向面分别在5-100m和10-100m波长范围内平顺性状态较好,由功能件安装等引起的1-5m和1—10m波长范围内的偏差应严格控制。 相似文献
13.
以聚偏氟乙烯为膜材料,二甲基亚砜为溶剂,通过相转化法制备不对称结构的聚偏氟乙烯微孔膜.考察不同凝胶浴组成浓度对膜结构和性能的影响.结果表明,二甲基亚砜容纳非溶剂水的能力非常弱.以二甲基亚砜为溶剂时,所成膜均为指状孔和球晶共存的结构.凝胶浴的组成将影响成膜机理,随着凝胶浴浓度的不断增大,凝胶分相延迟发生,指状孔的尺寸也随之增大,因此成膜孔隙率和水通量都逐渐升高.当凝胶浴为60%DMSO时,所成膜的孔隙率为78%,水通量达到623 L/m2h. 相似文献
14.
The focus of this paper is based on a research project undertaken in an outer London EPS. The research was in line with recent legislative and policy changes, highlighting the importance of the active participation of children in discussions made about them and their school life. Central to the project was the decision that pupils should be provided with an information booklet, regarding the educational psychologist's (EP) role within the assessment process-and by thus doing, promoting direct access and involvement between the pupil and the EPS. After initial research into this area had been undertaken, a pupil information booklet was produced. This booklet is currently being trialled in all primary schools within the education authority. 相似文献
15.
通过数学分析建立了EPS数学模型,应用线性PID控制建立了EPS控制模型．采用MATLAB／sim—ulink仿真软件建立了整个EPS的仿真模型．分别选取不同车速对EPS直线型助力特性进行了仿真实验,结果表明：当车速为0km／h时,EPS向汽车转向盘提供的最大助力转矩为20N·M,当车速为40km／h时,助力转矩减小为9N·M,当车速为80km／h时,助力转矩减为最小5N·M．为此,EPS直线型助力特性能贴近驾驶员对不同车速下的转向轻便性与高速行驶下良好路感性的需求． 相似文献
16.
LIU Zuohu LIU Renlong DU Jun TAO Changyuan LI Xiaohong College of Chemistry & Chemical Engineering Chongqing University Chongqing P. R. China College of Resources & Environmental Science Chongqing University Chongqing P. R. Chin 《重庆大学学报(英文版)》2004,3(1):61-64
1.IntroductionPhenolisanimportantchemicalindustrymaterial,butitalsoaboundswithserioushazardtoenvironmentandthreatstohumanhealth.Rigidruleshavebeenmadeoutonthephenoldischargeconcentration.Researchesonthetreatmentofphenolwastewaterwerecarriedoutinvariouscountries[1-5].Membraneseparationmethodsincludingreverseosmosis,ultrafiltrationandpervaporationhaveattractedmuchattentionforphenolwastewatertreatment,withcelluloseacetate(CA)membraneemployedmostly[6].Membranedistillationisanewmembraneseparation… 相似文献
17.
Gas-solid two-phase turbulent plane jet is applied to many natural situations and in engineering systems. To predict the particle
dispersion in the gas jet is of great importance in industrial applications and in the designing of engineering systems. A
large eddy simulation of the two-phase plane jet was conducted to investigate the particle dispersion patterns. The particles
with Stokes numbers equal to 0.0028, 0.3, 2.5, 28 (corresponding to particle diameter 1 μm, 10μm, 30μm, 100μm, respectively)
inRe=11 300 gas flow were studied. The simulation results of gas phase motion agreed well with previous experimental results.
And the simulation results of the solid particles motion showed that particles with different Stokes number have different
spatial dispersion; and that particles with intermediate Stokes number have the largest dispersion ratio.
Project (No. G19990222) supported by the Special Funds for Major State Basic Research of China 相似文献
18.
《天津大学学报(英文版)》2017,(6)
Although the performance of membrane reactors(MR) is highly affected by the ratio of membrane area-toreaction volume, there are few studies on this effect owing to the difficulties associated with reactor manufacture. In this study, an MR with high A/V ratio, a diameter of 35 m,and a height of 0.8 mm was fabricated. Separation performance of this MR was investigated in an n-butanol/water system. Esterification of acetic acid and n-butanol was used as the model reaction to investigate the performance of catalytically active membrane reactors(CAMR)with different A/V ratios. The reaction conversion was 38.59% in the CAMR with the high A/V ratio of 12,497/m,which was much higher than that in other CAMRs, for reaction time of 60 min and W/Vfratio of 0.093 g/mL.Excellent catalytic stability of the CAMR was confirmed by performing long-term stability experiments. 相似文献
19.
根据EPS在汽车上的实际装配关系,设计了EPS试验台,完成了性能实验(功能试验、助力电流特性试验、转向轻便性试验),并对试验结果进行了分析。试验结果表明EPS系统性能良好,方向盘可操作性好,能很好地实现助力效果。 相似文献
20.
1 Introduction The three-di mensional optical data storage is ofmuch interest in recent years[1-8].It has a great poten-tial for recording density.Currently,thetwo mainfac-tors affecting the density are the wavelength andspherical aberration caused by bot… 相似文献