陶瓷膜处理地表水的工艺

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50 nm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。     

陶瓷膜分离钛硅分子筛的实验与模型计算

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 nm),使膜保持高渗透通量.孔径小于200 nm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800 L/(m2.h).     

采用浸没式平板陶瓷膜处理东江原水的应用试验

采用过滤面积0.571 2 m2,孔径为60～70 nm的平板陶瓷膜,对东江原水进行过滤试验,研究在不同渗透通量、原水浊度、原水有机物浓度下陶瓷膜对浊度和有机物的去除效果,以及陶瓷膜跨膜压差的变化。结果表明,渗透通量、原水浊度和有机物浓度的升高都会引起跨膜压差的升高,其中有机物浓度的影响大于浊度的影响;膜出水水质分析表明陶瓷膜出水浊度稳定在0.1 NTU以下,各项指标除氨氮外都满足新的国家饮用水水质标准;陶瓷膜过滤能将病原微生物有效去除,从而提高水体的微生物安全保障水平;陶瓷膜能显著去除水中分子量大于2 000 Da的有机物,但对小分子有机物和无机离子基本没有去除效果。膜清洗试验表明,使用单种化学清洗剂时NaOH的效果最好。     

陶瓷膜脱除炼油厂焦化废水中焦粉

采用陶瓷膜分离技术脱除焦化废水中的焦粉,对不同孔径膜的处理效果进行分析,得出０．２μｍ的陶瓷膜可有效地除去废水中的焦粉;采用絮凝剂预处理废水后,１．０μｍ的氧化铝陶瓷膜也可达到脱除焦粉的目的,且过滤通量显著提高;考察了反冲过程对陶瓷膜过滤通量的影响,并对膜污染的化学清洗方法及重复性进行了实验。     

陶瓷膜澄清厚朴水提液膜污染机理的研究

采用一个经典模型描述了厚朴水提液过滤过程中的通量衰减,通过模型参数分析了膜的污染机理。分析结果表明孔径为50,200,500 nm的陶瓷膜主要由"完全孔堵塞"机理、"滤饼过滤"机理和"部分孔堵塞"机理控制;通过此污染机理的分析来指导膜清洗,孔径为50,200,500 nm的陶瓷膜清洗后分别恢复了84.5%,89.4%和90.0%左右;实验表明孔径为200 nm的陶瓷膜较适合厚朴水提液体系。     

气升式陶瓷膜过滤装置处理油田含聚采出水

采用新型的气升式陶瓷膜过滤系统处理油田含聚采出水,通过气液两相流替代单一的液相流动,降低了陶瓷膜处理油田含聚采出水过程的能耗,系统考察了曝气孔大小、曝气量和跨膜压差对膜渗透通量的影响。结果表明,采用孔径为微米级的曝气头曝气使高压气体在多通道膜管内的分布更为均匀,进而有效抑制膜污染和浓差极化,延缓通量衰减。当曝气孔径为1 μm时,渗透通量达到最大,且曝气量从300 L·h^-1增加到600 L·h^-1时,通量显著增加。此外,跨膜压差对膜的渗透通量影响显著,当跨膜压差为0.4 MPa时,渗透通量最佳。陶瓷膜处理油田采出水的出水水质各方面指标数据较为稳定,达到5.1.1回注水标准。最后,计算讨论了气升式陶瓷膜过滤装置的吨水能耗。     

气升式陶瓷膜过滤装置处理油田含聚采出水

采用新型的气升式陶瓷膜过滤系统处理油田含聚采出水,通过气液两相流替代单一的液相流动,降低了陶瓷膜处理油田含聚采出水过程的能耗,系统考察了曝气孔大小、曝气量和跨膜压差对膜渗透通量的影响。结果表明,采用孔径为微米级的曝气头曝气使高压气体在多通道膜管内的分布更为均匀,进而有效抑制膜污染和浓差极化,延缓通量衰减。当曝气孔径为1μm时,渗透通量达到最大,且曝气量从300 L·h~(-1)增加到600 L·h~(-1)时,通量显著增加。此外,跨膜压差对膜的渗透通量影响显著,当跨膜压差为0.4 MPa时,渗透通量最佳。陶瓷膜处理油田采出水的出水水质各方面指标数据较为稳定,达到5.1.1回注水标准。最后,计算讨论了气升式陶瓷膜过滤装置的吨水能耗。     

陶瓷微滤膜澄清钛白废酸研究

针对钛白废酸的资源化 ,采用陶瓷膜微滤澄清钛白废酸 ,为进一步扩散渗析回收硫酸提供预处理。研究了操作条件如压力、流速、质量浓度、温度等对过程的影响。研究表明陶瓷膜过滤钛白废酸具有很好的澄清效果 ,渗透液浊度小于 0 .5NTU ;废酸中较高质量浓度的硫酸亚铁使温度对过滤的影响复杂化 ,温度降低会使其在膜孔内发生结晶 ,产生难以恢复的堵塞 ;采用 5mg/kg以下的改性聚丙烯酰胺絮凝可以使膜通量有所提高 ,过多的絮凝剂会使膜产生吸附污染而降低通量。其他过程参数对膜通量有一定的影响     

硅藻土微孔陶瓷膜管

微孔陶瓷是一种新型无机非金属材料 ,具有耐高温、耐腐蚀、耐热冲击、孔径分布均匀、而且狭窄、成本低、使用寿命长等优点 ,因而被广泛应用于食品和生物制品的过滤、提纯及电解液的过滤、气体除尘及工业污水曝气装置中。微孔陶瓷的制备 ,国内外大多数使用氧化铝、氧化锆、氧化硅 ,用固态烧结法制成。微孔靠烧结过程中粒子间形成二次孔或添加成孔剂形成。硅藻土本身就具有大量微孔 ,因此是制备微孔陶瓷膜管的新原料 ,经反复研究试验 ,已研制成功平均孔径 2 .5μｍ ,孔隙率 0 .39的多孔陶瓷膜管 ,填补了国内空白 ,为硅藻土的深加工提供了一种…     

陶瓷膜处理废聚酯瓶片洗涤废水工艺研究

废聚酯瓶片洗涤废水属于碱性高浓度难降解废水,采用陶瓷膜错流过滤的方式进行试验,孔径50、200、500nm的陶瓷膜对SS和浊度截留率均在99%以上,渗透液存放24 h后保持澄清透明,对COD去除率为40.5%～43.3%,同时发现陶瓷膜对可溶物的透过性较好。陶瓷膜分离工艺参数优化试验表明,在膜孔径为50 nm,操作温度为40～50℃,平均错流速率为2.10 m/s,跨膜压差为0.13～0.15 MPa的条件下,陶瓷膜渗透通量衰减较慢。采用质量分数为0.2%NaClO溶液和0.3%草酸溶液的组合方式进行膜清洗试验,膜通量恢复率达80%以上。     

Design and fabrication of whisker hybrid ceramic membranes with narrow pore size distribution and high permeability via co-sintering process

Ceramic microfiltration membranes (MF) with narrow pore size distribution and high permeability are widely used for the preparation of ceramic ultrafiltration membranes (UF) and in wastewater treatment. In this work, a whisker hybrid ceramic membrane (WHCM) consisting of a whisker layer and an alumina layer was designed to achieve high permeability and narrow pore size distribution based on the relative resistance obtained using the Hagen-Poiseuille and Darcy equations. The whisker layer was designed to prevent the penetration of alumina particles into the support and ensure a high porosity of the membrane, while the alumina layer provided a smooth surface and narrow pore size distribution. Mass transfer resistance is critical to reduce the effect of the membrane layers. It was found that the resistance of the WHCM depended largely on the alumina layer. The effect of the support and whisker layer on the resistance of the WHCM was negligible. This was consistent with theoretical calculations. The WHCM was co-sintered at 1000?°C, which resulted in a high permeability of ~?645?L?m^?1 h^?1 ;bar^?1 and a narrow pore size distribution of ~?100?nm. Co-sintering was carried out on a macroporous ceramic support (just needed one sintering process), which greatly reduced the preparation cost and time. The WHCM (as the sub-layer) also showed a great potential to be used for the fabrication of ceramic UF membranes with high repeatability. Hence, this study provides an efficient approach for the fabrication of advanced ceramic MF membranes on macroporous supports, allowing for rapid prototyping with scale-up capability.     

Pr0.6Sr0.4Co0.2Fe0.8O3-δ中空纤维陶瓷膜的制备及其透氧性能

采用改进的溶胶-凝胶法制备了一系列陶瓷粉体Pr1-xSrxCo1-yFeyO3-δ(x=0.2、0.4、0.6;y=0.2、0.4、0.6、0.8).运用相转化/烧结技术制造出了Pr0.6Sr0.4Co0.2Fe0.8O3-δ(PSCF6428)中空陶瓷纤维膜.用热分析、X射线衍射仪、扫描电镜、X射线能谱等技术对制备的...     

Sol-gel derived zirconia membrane on silicon carbide substrate

To enhance the high temperature and chemical corrosion resistances of ceramics membrane, a ZrO₂/SiC ceramic membrane was prepared through sol-gel route followed by the dip-coating technique. The substrate layer was made of pure silicon carbide phase by evaporation-condensation process, and the separation layer was made of zirconia phase by solid-phase sintering process. The substrate layer was sintered at 2200 ℃ in the vacuum, and the pores were distributed in a narrow size range from 4.5–6.0 μm. When the membrane was sintered at 700 ℃, a defect-free separation layer formed on the substrate. With the increase of sintering temperature, the average pore size of the separation layer declined from 63 to 48 nm, and the water permeability declined from 355 to 273 L/(m²·h·bar). Our results indicate the ZrO₂/SiC ceramic membrane has potential applications in the separation of high temperature or chemically corrosive wastewaters.     

氧化铝多孔支撑体的制备工艺

叙述了用挤出成型法制备无机膜支撑体的工艺,研究了原料粒径、成孔剂用量和烧结温度对所制得多孔氧化铝支撑体性能的影响。研究结果表明,用粒径小于10μm的-αA l2O3粉体,以7%碳粉为成孔剂,烧结温度为1300℃,可以成功制得孔径分布较窄、平均孔径为2.1μm、孔隙率为48.9%的多通道无机膜支撑体。     

Porous cenosphere ceramic microfiltration membrane: Preparation,characterization, permeability evaluation,and cost estimation

Ceramic membranes are now receiving greater attention and are regarded as the best alternative option for reducing energy use. There are currently a number of limitations on the use of ceramic membranes, including high raw material costs and high sintering temperatures during synthesis. Cost-effective raw materials were employed in the synthesis of ceramic membranes to get around these restrictions. Utilizing a straightforward pressing technique, circular disc-type membranes were prepared. To assess the membrane properties, the impact of sintering temperatures between 700 and 900°C was examined. By varying the sintering temperature, the average membrane pore diameter was observed. The membrane, which was sintered at 800°C, had pores that were on average 110 nm in size. Furthermore, the porosity of these synthesized membranes ranged from 22% to 35% with an average pore diameter of 74–121 nm. These manufactured membranes showed very good chemical stability when both acidic and basic solutions were used. Various characterization methods, including thermogravimetric analysis (TGA), x-ray diffraction analysis (XRD), and scanning electron microscopy (SEM), were used. Thermo-gravimetric investigation revealed that the synthesized cenosphere membrane required a minimum sintering temperature of about 700°C. The flux measured with deionized water and the applied transmembrane pressure showed an upward trend. The impact of sintering temperature on permeate flux was investigated. The results showed that as the sintering temperature increased from 700°C to 900°C, the flux reduced. It was determined that the synthesized membrane cost ₹1618.80/m².     

Three-dimensional printing of high-flux ceramic membranes with an asymmetric structure via digital light processing

In this study, a novel method was proposed for preparing high-flux ceramic membranes via digital light processing (DLP) three-dimensional (3D) printing technology. Two different alumina powders were well dispersed in a photosensitive resin to form a UV-curable slurry for DLP 3D printing. The effects of the grading ratio on the viscosity of the slurry and the porosity, pore size distribution, mechanical strength, roughness, and permeability of the ceramic membranes were systematically investigated. The thermal treatment conditions were also studied and optimized. The obtained ceramic membranes exhibited a uniform pore size distribution, a high porosity, a low tortuosity factor, and an asymmetric structure. The combination of these factors led to a high flux for the 3D-printed ceramic membranes. DLP 3D printing exhibited a good potential to be a strong candidate for the next generation of ceramic membrane fabrication technology.     

平板α-Al2O3陶瓷微滤膜的制备与表征

采用固态粒子烧结法和浸拉提渍工艺研制出α-Al2O3平板式陶瓷微滤膜,探讨涂膜液中固含量对膜孔径及纯水通量的影响,并研究涂层工艺及烧成制度对膜形成的作用。同时对微滤膜的孔径大小及分布,膜孔隙率、纯水通量及抗弯强度等性能进行表征。实验结果表明,制备出平均孔径为0.7μm的平板陶瓷膜,其具有表面性质连续完整、孔径分布窄以及机械强度大的特点。     

Monoclinic Zirconia Microfiltration Membranes: Preparation and Characterization

Microfiltration zirconia membranes were prepared by slip casting from two pure zirconia powders derived from different processing techniques. Powders had almost the same mean particle size but were different in surface area, particle size distribution and morphology. Rheology of zirconia slips was studied in order to prepare a well-dispersed slip suitable for slip casting. The powders showed different dispersibility in the preparation of slips by colloidal processing. The effect of sintering temperature and holding time on porosity, pore size distribution, phase composition, microhardness and microstructure of unsupported membranes are studied and discussed in relation to the membrane processing and properties of powders resulting from different processing routes. Pore size distribution of membranes reflected the differences in morphology of particles and the state of agglomeration in the green samples.Isothermal sintering at 1100°C resulted in some tetragonal phase retained at room temperature in the monoclinic structure. Cracking occurred in membranes sintered above 1150°C due to the volume change in phase transformation. Densification behavior, removal of porosity and the hardness property showed differences that are attributed to the differences in powder processing and characteristics of powders. Crackfree membranes can be prepared by sintering at 1100°C from both powders.     

Fabrication of low cost,green silica based ceramic hollow fibre membrane prepared from waste rice husk for water filtration application

In order to develop low cost ceramic membranes and effectively utilize abundantly and dumped waste agriculture, fabrication of green silica based ceramic hollow fibre membranes from waste rice husk was evaluated. Rice husk was converted into amorphous and crystalline silica based rice husk ash (ARHA and CRHA) by burning process at 600?°C and 1000?°C, respectively. The properties of silica based rice husk ashes were studied by transmission electron microscopy (TEM), x-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), BET analysis, thermogravimetry and differential thermal analysis (TG/DTA) and x-ray fluorescence (XRF). Effect of silica content and sintering temperature towards membrane fabrication were investigated and characterized in term of morphological properties, mechanical strength, surface roughness, pore size distribution, porosity and pure water flux (PWF). The ceramic hollow fibre membrane (CHFM) prepared at 37.5?wt% CRHA content and sintered at 1200?°C achieved a good mechanical strength (71.2?MPa) and excellent porosity (50.2%). As a result, high PWF with value ~ 300?L/m² h and stable at 20?min was obtained. Due to the excellent pure water flux, the prepared ceramic membrane from waste rice husk hold promise for water treatment application.     

The fabrication and characterization of sintered diatomite for potential microfiltration applications

Porous ceramic membranes have lately become a subject of special interest due to their outstanding thermal and chemical stability. We investigated whether a sintered diatomite support layer could also serve as a separation layer to minimize any processing difficulties, and investigated whether the support layer and the separation layer could be made from the same material to avoid a thermal mismatch during a high-temperature sintering process. We prepared sintered diatomite as a porous ceramic membrane for microfiltration, as diatomite particles are inherently porous and irregular. The pore characteristics of the sintered diatomite specimens were studied by scanning electron micrography, mercury porosimetry, and capillary flow porosimetry.