膜技术在荷叶黄酮分离纯化中应用

运用膜技术对荷叶黄酮提取液进行纯化.实验分别采用微滤膜和超滤膜对荷叶黄酮提取液进行初步纯化,研究表明孔径为50 nm的微滤膜Ⅱ对荷叶黄酮提取液有较好的除杂效果,黄酮透过率为97.4％,平均通量为186.7 L×h-1×m-2,且运行稳定;采用纳滤膜和反渗透膜对微滤膜的滤液进行浓缩,研究表明,纳滤膜在浓缩过程中能去除部分盐分等小分子物质,进一步纯化了黄酮溶液,纳滤膜平均通量为32.8L×h-1×m-2,透过率0％.     

Elaboration of new tubular ceramic membrane from local Moroccan Perlite for microfiltration process. Application to treatment of industrial wastewaters

In this study, an original microfiltration tubular membrane (M1) made from local Moroccan Perlite was used to treat three wastewater types: effluents coming from beamhouse section of tannery (effluent A), textile effluent coming from jeans washing process (effluent B), and dicing wafer effluent generated by electronic industries (effluent C). The prepared membrane is composed of two layers of Perlite with two different granulometries: a macroporous support with a pore diameter centered near 6.6 μm and porosity of about 42%, and a microfiltration layer, performed by slip casting method, with a mean pore size of 0.27 μm. The water permeability determined of the membrane is 815 L/h m² bar. Tangential microfiltration using Perlite membrane proved to be effective in removing pollutants from the three effluents with almost the same efficiencies than that obtained with a commercial Alumina membrane (M2) with a pore diameter of 0.2 μm and a water permeability of 1022 L/h m² bar. Tangential microfiltration process operated at lower pressure (1 bar) was seen to remove turbidity from the three feeds completely. Perlite membrane allowed significant reduction of Chemical Oxygen Demand COD (50–54%) and Total Kjeldahl Nitrogen TKN (56%) of beamhouse effluent. It showed a significant decrease of COD (54–57%) and a complete discoloration of textile wastewater.     

The treatment of industrial effluents containing sodium hydroxide to enable the reuse of chemicals and water

An economically viable treatment sequence has been developed and piloted at two textile factories for the recovery and reuse of water, chemicals and heat energy from sodium hydroxide effluent produced during the scouring of cotton fibre.The treatment sequence involves pretreatment of the scour effluent by neutralisation, using an acidic gas, cross-flow microfiltration and charged membrane ultrafiltration (also called nanofiltration). The sodium hydroxide is then recovered in an electrochemical membrane cell with the simultaneous evolution of acidic gas which is recycled within the treatment process.Two possible configurations of the treatment process, where the acidic gas is either chlorine or carbon dioxide, have been discussed. Pilot plant results have been presented for both systems. The carbon dioxide system was the preferred route and is discussed in detail.The pretreatment sequence neutralised the scour effluent, lowered its chemical oxygen demand by 86% and removed 65% of both the calcium and the organics and 50% of the magnesium. The sodium hydroxide (100 to 200 g/l) and depleted brine solution (total solids 500 mg/l) from the electrochemical membrane cell were of suitable quality for reuse in the factory process.The electrochemical membrane cell produced sodium hydroxide at 62% current efficiency at an electrical power consumption of 4 000 kWh/ton 100% NaOH. The effect of electrolyte, in particular, anolyte flow rate, temperature and concentration on the limiting current density and power consumption has been investigated. Some design data for a full scale treatment plant has been presented.The operation of an acceptable background concentration closed-loop recycle wash system in the scour process was found to reduce the required membrane area by 82%.Minimum dissolution of the precious metal oxide anode coating occurred and long anode life was predicted. Serious electromembrane fouling, with increased resistance, was not apparent.     

Performance of a new ceramic microfiltration membrane based on kaolin in textile industry wastewater treatment

A ceramic microfiltration membrane with a porosity of 40.2%, mean pore diameter of 0.27?μm, and a flexural strength of 55?MPa was prepared and applied for treatment of two types of textile dye-bath effluents. The ceramic membrane had a water permeability of 1376?L/m².h.bar and showed excellent corrosion resistance against basic medium. Considerable removal of COD (25%), TDS (31%), BOD (39%), turbidity (21%), sulphates (34%), chlorides (33%), and color (26%) from textile effluents was achieved in the microfiltration treatment along with complete (100%) removal of TSS. This study revealed that filtration of textile effluents using a sub-micron range ceramic membrane (0.27?μm) is more effective than traditional microfiltration membranes (2–10?μm). The flux data fitted well with the standard pore blocking model indicating that the removal of various contaminants is due to adsorption of solutes on the interior surfaces of membrane pores.     

Development of a bioprocess combined with membrane technology for the treatment and recycling of textile effluent

A mixed culture of dye-decolorising Pseudomonas spp. was immobilised on polyurethane foam, and used in a bench-scale continuous culture bioreactor to treat textile effluent for colour removal. The provision of soluble wheat starch (0.2% w/v) to the culture medium promoted growth of biomass and enhanced decolorisation of effluent in the bioreactor. The bioprocess was further combined with membrane filtration technology to improve the quality of treated effluent. The treated effluent showed 90, 82 and 60% reduction in COD, BOD₅ and toxicity levels, respectively, and had potential for re-use in dyeing processes. The colour difference of the cotton fabrics dyed using the treated effluent samples compared to those dyed using normal supply water was found to be industrially acceptable. The described process could improve treatment efficiency and allow water recycling within the textile factory.     

反渗透在电镀工艺和废水处理应用上的局限性

简单介绍了微滤、超滤、纳滤、电渗析等膜分离技术,重点分析了反渗透膜的要求以及影响其寿命的因素,讨论了废水处理用反渗透系统的配置问题,说明了电镀中适于反渗透技术应用的场合。讨论指出:反渗透仅对废水中的限排物起截留浓缩作用,所得浓废水还须用化学法等作二次处理;反渗透的适用场合有限且应具备相应条件。     

MBR-光催化氧化处理印染废水的试验研究

利用MBR-光催化氧化的组合工艺处理某纺织园区综合废水,对反应装置进行了连续运行效果的考察.结果表明,MBR对废水COD、浊度,色度降解率分别达到93.5%、99.9%和98.9%;MBR中污泥沉降性能明显优于SBR,能有效控制污泥膨胀现象;出水的透光性大大提高,经光催化氧化后COD、BOD、浊度、色度分别稳定在35.0mg·L~(-1)、2.7 mg·L~(-1),2.3NTU、3倍,水质达到GB 18918-2002的一级A排放标准和CJ/T48-1999的生活杂用水要求.     

城市污水深度脱色技术研究进展

城市污水厂二级生物处理出水中的色度物质构成复杂且难以处理,随着排放标准日益严格和再生水用量的不断提高,解决色度问题逐渐成为研究热点。本文介绍了色度的概念和组成,总结了国内外研究者利用混凝、氧化技术、膜过滤技术和组合工艺去除色度的效果和机理,分析了影响其脱色效果的因素,并简要评述了各项技术的应用前景。总结发现,纳滤（去除率90%～100%）、臭氧及光催化及其组合工艺（60%～80%）效果最优,其次是混凝、超滤及其组合工艺（50%）,而微滤、含氯氧化剂及紫外照射工艺脱色效果较差。最后对本领域的发展前景作了展望,提出研究色度物质的来源及构成,关注脱色工艺性能及复色的可能性,以及实现脱色、消毒和去除微量有机物的多功能性,将是未来的研究重点。     

Nanofiltration of wastewaters from the fish meal industry

The wastewaters generated in the fish meal industry, a water-intensive industry, contain a high organic load comprising a significant amount of proteins. Therefore, they should not be discharged without a suitable treatment in order to prevent negative impacts in the environment, and allow the recovery of high added value products. The effluent generated in a fish meal plant located in Talcahuano, Chile, was characterized, and pre-treated by microfiltration (MF) cartridges in series (80, 20 and 5 μm). A multi-channel ceramic membrane of 1 kDa MWCO, Kerasep NanoN01A, was used in the nanofiltration (NF) experiments. The operating conditions were optimised in total recycling mode, and the subsequent concentration experiment was carried out at 4 bar, 4 m/s, ambient temperature and natural pH. The results from this work clearly show that NF is an efficient and ecologically suited environmental technology for decontamination and recycling of the wastewaters generated during the fish meal production, as it allows both the recycle of water (permeate stream) and proteins (concentrate stream) into the fish meal process, besides environmental pollution abatement. Although the membrane undergoes severe fouling, it can be effectively cleaned through a basic-acid washing cycle.     

二段淹没式膜生物反应器处理城市污水的研究

采用九保田板式膜,设计了二段淹没式膜生物反应器处理城市生活污水。运行结果显示,二段淹没式膜生物反应器能够增强高能级生物体蠕虫生长与少产污泥的目的。在污泥负荷为0.35~0.65g[COD]/(g[SS]·d)和容积负荷为2~5g[COD]/(L·d)的条件下,反应器出水COD和NH3-N的质量浓度分别为18.67mg/L和0.24mg/L,污泥产率为0.1kg[SS]/kg[COD]。     

Applicability of nanofiltration for the advanced treatment of landfill leachate

Landfill leachates are generated from municipal solid waste landfills under the action of water percolating through the landfilled waste. A treatment system using a combined membrane engineering process was developed to effectively treat the landfill leachate in the Dahanzhuang sanitary landfill (Tianjin, China). The process combines a membrane bioreactor (MBR) and nanofiltration (NF) technology to treat the leachate. The results indicate that the NF system, including the hollow‐fiber NF membrane, is an appropriate advanced treatment alternative for landfill leachates. This system provided good removal of chemical oxygen demand and color. The membrane flux renewal reached over 96% after washing with 0.01 mol/L HCl. As a result, the effluent water quality met effluent discharge standards (GB16889‐2008). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

聚酰胺非对称纳滤膜在印染废水深度处理中的应用

利用自制的聚酰胺非对称纳滤膜处理水溶性阴离子染料废水,并与NF270商品膜性能进行了比较研究。在0.7 MPa和25℃的条件下,所制纳滤膜对3种阴离子染料的截留率均大于95%。24 h染料连续脱盐运行条件下,膜的水通量保持在50 L.m-2·h-1,染料截留率96%以上,脱盐率稳定在5%以下,具有较好的选择分离性和耐污染性。2种纳滤膜的性能对比研究表明,所制PMIA非对称纳滤膜的染料截留能力和耐高温性优于NF270商品膜,但膜通量稍低。     

Economical treatment of reverse osmosis reject of textile industry effluent by electrodialysis–evaporation integrated process

Membrane separation methods such as electrodialysis (ED) can reduce the volume load on evaporators by facilitating further concentration of rejects from reverse osmosis (RO) plants. ED studies were carried out on a bench-scale system using five membrane cell pairs to obtain a textile effluent concentrate containing approximately 6 times the quantity of salts present in the RO reject. The limiting current densities were determined to be in the range 2.15–3.35 amp/m² for feed flow rates varying from 18 to 108 L/h. Apart from feed rate, the influence of volume of concentrate and current on membrane performance was evaluated to optimize current utilization. An estimation of energy requirement of an integrated process constituting ED and evaporation for concentration of inorganics present in textile effluent from 4.35% to 24% was made and found to be approximately one eighth of the operating cost incurred by evaporation alone. Detailed design of a commercial ED system revealed that a membrane area of 13.1 m² was required to treat a feed rate of 1500 L/h. The payback period to recover capital investment was found to be 110 days.     

焦化污水纳滤膜深度处理的研究

介绍了污水纳滤深度处理工艺,对纳滤膜在焦化污水深度处理中的研究表明,纳滤膜运行稳定,安全可靠,产水率高,浓缩液量少,脱盐率达50%左右,对COD有较高的截留率,产水COD<50mg/L,可以满足循环水补充水的要求,应用于焦化污水回用可以满足工艺要求,且经济、可行。     

Nanofiltration of textile wastewater for water reuse

The textile industry produces a large amount of wastewater that is highly coloured with high loading of inorganic salt. Crossflow nanofiltration using thin film composite polysulfone membrane was used to recover the electrolyte solution and reject the colour. Using a synthetic textile effluent of reactive dye and NaCl solution, the study focused on the mechanism controlling flux and rejection by varying four main parameter; crossflow velocity, initial dye concentration, feed pressure, and electrolyte concentration. Results show that flux was dominated by the osmotic pressure created from the presence of NaCl, and that dye concentration did not significantly effect the flux or rejection. Working at low pressures of up to 500 kPa, relatively high fluxes were obtained, with an average dye rejection of 98% and NaCl rejections of less than 14%. Thus, a high quality of reuse water could be recovered. Even after a number of cycles, the membrane did not foul irreversibly, with an overall mean waterflux recovery of 99%.     

南瓜多糖清洁生产提取工艺研究

通过正交试验设计和膜分离技术应用进行清洁生产工艺研究,试验结果显示,南瓜多糖提取最佳条件为温度40℃,浸提时间0.5 h,料液比1∶3,提取液经微滤膜N100除杂和纳滤膜DLC浓缩,南瓜多糖截留率达94.5%,南瓜多糖的纯度为67.5%。企业采用此清洁生产工艺可降低成本,大大提高经济效益。     

Separating Cyanide from Coke Wastewater by Cross Flow Nanofiltration

Investigations on separation of cyanide from coke wastewater were carried out in a cross flow nanofiltration membrane module following microfiltration of real industrial wastewater. Different composite polyamide nanofiltration membranes were used in the system while studying their effectiveness in cyanide separation under different operating conditions. Transmembrane pressure, pH, and cross flow velocity exhibited strong influence on percentage removal of cyanide. 94% cyanide rejection with a permeate flux of 79 liters per hour at a transmembrane pressure of 13 kg/cm² and at a volumetric cross flow rate of 700 liters per hour was achieved. The membrane module with a composite membrane having high negative charge was successfully operated without any significant loss in flux even after 72 hours operation. These encouraging results show that microfiltration and nanofiltration with properly selected membranes in an appropriate module could lead to a practical solution to a longstanding problem of cyanide removal from industrial wastewater.     

纳滤—电渗析处理纤维染色废水反渗透浓水研究

针对反渗透处理纤维染色废水过程中产生的高COD、高色度和高盐含量浓水,研究采用纳滤-电渗析集成技术对其进行脱色、一二价盐分离和盐浓缩中试。结果表明,纳滤膜NF5和NF4分别用于废水脱色和分盐,经过2级纳滤处理后废水色度降低至原水的1/1200,COD从原水的200 mg/L降低至小于100 mg/L,Cl^-和SO4^2-离子的质量浓度比从原水的3:2提高到21:1。电渗析可将纳滤膜NF4透过液中的总溶解盐浓缩至质量分数10%以上。盐浓缩液可重新用于染色,染色效果良好。表明该集成技术在纤维染色废水的深度处理上具备良好的工业化应用前景。     

纳滤膜技术在庆大霉素B浓缩中的应用

阐述了纳滤膜对庆大霉素B溶液的浓缩性能。通过实验得到了时间、浓缩倍数、压力等因素对膜通量的影响,并在此基础上建立了一套每天处理10 m3物料的进口纳滤膜浓缩系统,该系统在8小时内将10 m3物料浓缩50倍,最终物料体积为200 L,浓缩液的效价达十万以上,对物料的收率高于98%,效果明显。     

Treatment of a textile effluent: application of a combination method involving adsorption and nanofiltration

A combination of adsorption and nanofiltration (NF) was adopted for the treatment of a textile dyehouse effluent containing a mixture of two reactive dyes. The effluent stream was first treated in a batch adsorption process with sawdust as an adsorbent to reduce the dye concentration of the effluent by about 83% for Dye 1 and 93% for Dye 2. The effluent from the adsorption unit was passed through an NF unit for the removal of the remaining small amount of dyes and to recover the associated chemicals (mainly salt) in the effluent stream. The dyes remaining after this step were less than 1 ppm. The percentage removal of COD was greater than 99%, and the salt recovery was on the order of 90%. Equilibrium studies were carried out with synthetic solutions of the dyes (both single component as well as two-component systems) at room temperature. The adsorption rates were studied in detail using varying amounts of the adsorbent. NF of the effluent was performed in a cross-flow system using a 400 molecular weight cut-off membrane. A detailed study was carried out to observe the effect of the process parameters, namely applied pressure and bulk velocity on the process outputs such as dye rejection, COD removal, permeate flux and salt recovery. Finally, direct NF of the effluent (with the original high concentration) was undertaken, and the performance of the process was compared with the combination method. The permeate flux for the proposed combined method was found to be about twice that for the direct NF method. The dye rejection improved significantly compared to adsorption.