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1.
陶瓷膜处理地表水的工艺   总被引:1,自引:0,他引:1  
采用混凝沉降与陶瓷膜超滤的组合工艺处理地表水,考察操作模式、膜孔径、膜构型以及膜通量等对膜过滤性能的影响.结果表明:在恒压操作下,终端过滤的操作压差应小于0.075 MPa,对于孔径大于50nm的陶瓷膜而言,膜通量随孔径变化不大;错流过滤的膜通量随孔径增大而增大;错流过滤的渗透通量是终端过滤的1.5 -2.2倍.恒通量操作下,蜂窝陶瓷膜过滤性能优于19通道陶瓷膜,并在恒通量150 L/( m2.h)下稳定运行.混凝沉降-陶瓷膜组合工艺对浊度的去除率大于99%,对吸收254 nm波长紫外线有机物(UV254)的去除率大于47.7%,产品水的部分指标优于GB 5749-2006中的指标.  相似文献   

2.
在面向过程的陶瓷膜材料设计理论模型的基础上,以TS-1钛硅分子筛悬浮液固液分离为应用体系,计算了陶瓷膜分离过程的操作条件与渗透性能的关系,与实验结果有良好的一致性.计算表明,对于平均粒径为290 nm的钛硅分子筛体系,陶瓷膜存在最优孔径区间(200~300 am),使膜保持高渗透通量.孔径小于200nm时膜通量随孔径增大而增大,孔径大于300 nm时膜通量随孔径增大而减小;采用孔径为200 nm的陶瓷膜过滤钛硅分子筛,渗透通量随时间的变化关系与模型预测结果一致,稳定通量达到800L/(m2·h).  相似文献   

3.
采用浸没沉淀法、织物为支撑体制备复合型高强度膜材料.提出了支撑材料的筛选方案,研究了带支撑的复合膜在成膜过程中的起皱原因,并成功制备了支撑型复合膜.考察了不同质量分数的聚偏氟乙烯(PVDF)、聚砜(PSF)收缩率、拉伸强度、平均孔径、纯水通量等因素对复合膜性能的影响.采用膜通量、孔径分析、力学强度、扫描电镜( SEM)、收缩率对复合膜进行分析与表征.结果表明:高分子材料在成膜过程中的收缩与支撑材料的收缩的差异可能是起皱的重要原因.收缩率大于50%,起皱收缩明显;收缩率低于40%,复合膜平整.所制备的高强度复合膜的拉伸强度大于35 MPa,膜孔径为0.07~0.6μm,水通量为5 000~ 17 000 L/(m2·h·MPa).  相似文献   

4.
采用孔径分别为50、200和500 nm的陶瓷膜处理碱性酪蛋白水溶液,考察操作条件及pH对过滤通量和截留率的影响,并研究酪蛋白胶束在不同pH下的聚集行为.结果表明:采用孔径为200 nm的陶瓷膜过滤1 g/L的酪蛋白溶液,在pH=13,操作压差0.10 MPa,膜面流速3.0 m/s条件下,可获得膜通量266 L/(m2·h)和酪蛋白截留率71.8%,综合效果好.酪蛋白的胶束尺寸和黏度随pH的增大而增大.膜过滤通量随pH增大而减小 ;截留率随pH增大而增大.  相似文献   

5.
丹参水提液的无机膜澄清过程   总被引:1,自引:0,他引:1  
利用无机陶瓷膜对丹参水提液进行了分离澄清研究,主要考察了膜管孔径、跨膜压差、膜面流速、温度和反冲条件等因素对分离过程的影响,以膜通量、浊度及固含量等指标来考察膜分离的性能.实验结果表明,膜管孔径越大,膜通量也越高,渗透液的浊度、固含量和黏度均变小.跨膜压差越大、膜面流速越高、温度越高,有利于提高膜通量;通过反冲实验可知较低的反冲时间和较短的反冲周期对膜分离比较有利.  相似文献   

6.
利用陶瓷膜和纳滤膜的组合分离技术代替板框对霉酚酸发酵液的过滤,对霉酚酸发酵液进行澄清和浓缩实验.采用陶瓷膜(0.1μm)和S-372纳滤膜技术对霉酚酸发酵液进行研究,研究了膜系统的通量、加水倍数和浓缩倍数等因素对膜分离性能的影响.在陶瓷膜加水4倍时,霉酚酸的收率可达96.5%,平均通量可达160~180 L/(m2·h);纳滤对霉酚酸的截留率和收率均达到98%,霉酚酸效价可浓缩到21 g/L,通量为25 L/(m2·h)左右,与板框滤液效价相比,提高了3.5倍.结果表明:陶瓷膜和纳滤膜的组合工艺在产品收率及产品质量方面都明显优于传统的板框过滤,具有良好的应用潜力.  相似文献   

7.
用陶瓷微滤膜组装的膜生物反应器,在低流速下对生活污水进行处理.选择了适宜膜孔径的微滤膜,制定了一套有效的陶瓷膜恢复方法.在膜面流速为1.6 m/s,操作压差为0.1 MPa条件下,研究了絮凝剂加入对过程稳定通量的影响.结果表明:无絮凝剂时膜稳定通量为89.2 L·m-2·h-1·MPa-1,易引起多通道的堵塞.添加不同量FeCl3絮凝剂后,膜稳定通量分别提高了122.9%、238.0%.  相似文献   

8.
以高温凝结水的净化为应用背景,采用孔径为4 nm的陶瓷膜去除水中微量Fe3+。考察Fe3+浓度、pH及操作参数等对陶瓷膜分离性能的影响。结果表明:随着Fe3+浓度增大,陶瓷膜对Fe3+的去除率减小;当Fe3+质量浓度小于50 mg/L时,陶瓷膜对Fe3+的去除率大于98%,操作条件如温度和膜面流速(CFV)的提高均有利于提高陶瓷膜对Fe3+的截留率;温度升高有利于提高膜过滤通量,操作压力对通量的拐点为0.2 MPa,膜面流速的拐点在3 m/s左右;pH对Fe3+的去除率影响显著,主要由于pH影响了Fe3+在水中的化学构成。  相似文献   

9.
初步建立了颗粒体系微滤过程中的膜微观结构与性能关系模型,对陶瓷膜孔径对膜通量的影响进行模拟计算.结果表明,对于颗粒悬浮体系的分离,存在最优膜孔径使膜通量最大,研究工作有助于深入理解膜微观结构对宏观性能的影响.  相似文献   

10.
采用晶种法在不锈钢网表面(stainless steel mesh, SSM)制备连续致密的ZIF-8 (zeolite imidazole framework-8)膜,通过控制ZIF-8膜的晶化时间,实现对复合膜的孔径调控.ZIF-8膜晶化12 h, ZIF-8/SSM复合膜的孔径为26μm,并表现出水下疏油的特性.在水预润湿条件下,ZIF-8/SSM复合膜可对己烷-水混合物进行有效分离,且油水混合物的分离效率高达99.5%,最大水通量为38.0 L/(m2·s).经10次循环分离测试,膜的分离效率和水通量保持不变,表明复合膜具有良好的循环稳定性.复合膜用于煤化工含油废水的分离,表现出良好的分离效果.可为拓展金属有机骨架材料膜在煤化工油水分离方面的研究提供参考.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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