离子交换水处理技术文摘

标题的装置包括装有预涂中空纤维的过滤器的过滤一脱盐箱，一个装填离子交换树脂的柱塔，用于监测徨水电导率或CL~-浓度的装置和依靠来自监测器的反馈信号来控制离子交换树脂数值的装置。阴离子交换树脂对阳离子交换树脂的数值的装置。阴离子交换树脂对阳离子交换树脂的混合比例控制在>0.5:1,离子交换树脂的平     

柴油车排气净化技术研究的进展

介绍了柴油机排放特征,排放标准及欧洲、日本的汽车界采用的柴油车排放控制技术.本文重点是评述柴油机排放后处理技术的新进展.氧化催化剂已是一种商业化产品,在小轿车、轻型车和重型车上广泛安装使用,改进方向是扩大温度窗口和提高抗SO2氧化能力;颗粒物过滤器产业化的关键技术是过滤器再生技术,被动燃烧再生技术系统是研究开发的重点,开发中的连续再生过滤器系统被认为是未来标准的配套技术,但需用超低硫柴油燃料;尿素-SCR技术已成功进行重型柴油车的NOx净化试验,改进方向是装置小型化和防止NH3泄漏;实现颗粒物和NOx同时净化的四元催化转化器及非热等离子体技术正在小轿车、重型车上进行应用试验,近年内可望推向市场.     

高效液相色谱-串联质谱法测定玩具中双酚A的迁移量

建立了测定玩具中双酚A迁移量的高效液相色谱-串联质谱(HPLC-MS/MS)方法。改进了欧盟玩具安全标准EN 71-10:2005以水为模拟液的迁移条件,提出了迁移后模拟液经混合纤维素酯(MCE)过滤器过滤后直接由HPLC-MS/MS分析的方法。研究了不同材质针式过滤器对双酚A的影响。结果表明,聚酰胺(PA、尼龙66)和聚醚砜(PES)过滤器会导致双酚A大量损失,而MCE过滤器对双酚A的回收率最高( 90%)。该方法在2~100μg·L~(-1)范围内呈良好线性关系,相关系数(r~2)大于0. 999,方法检出限(LOD)为0. 30~0. 52μg·L~(-1),定量下限(LOQ)为1. 00~1. 72μg·L~(-1),加标回收率为96. 5%~106%,相对标准偏差(RSD,n=7)为2. 0%~8. 6%。该法可满足欧盟指令(EU) 2017/898中双酚A迁移限量(0. 04 mg·L~(-1))的要求,且避免了因过滤器选择不当导致的双酚A损失,具有较好的实际意义。     

硫氰酸盐分光光度法测定岩矿中钨量的改进

钨在工业中应用非常广泛,主要用于生产硬质合金和钨铁[1],钨粉可烧结成各种孔隙度的过滤器,钨的一些化合物可作荧光剂、颜料、燃料[2].     

高分子复合物纤维的研究进展

功能化和智能化是纤维发展的趋势.单一组分纤维难以满足日益发展的需求,而多组分纤维能够集中不同组分的特点,实现性能的集成与优化.通过非共价相互作用,高分子聚集而形成多组分均相体系,称为高分子复合物.利用高分子复合物的形成过程使纤维成型;或者直接利用高分子复合物进行纺丝而得到的纤维称为高分子复合物纤维.高分子复合物纤维,各组分可以达到分子层面上的相容性,给我们提供了一个功能纤维和智能纤维设计开发的平台.本文详细阐述了各类高分子复合物纤维的研究现状,并展望高分子复合物纤维的未来发展.     

气相耗材对系统性能的影响

 叙述了气相耗材如气体过滤器、柱卡套、进样口密封垫、衬管等的性能及其选择和安装对系统运行的影响 ,指出要想使气相系统保持最佳运行状态 ,必须有性能优良、干净及选择得当的耗材作保证。     

PVA/SiO2-TiO2杂化电纺纤维膜的形态与性能

以正硅酸乙酯(TEOS)、钛酸四丁酯(TBT)和聚乙烯醇(PVA)为原料, 用溶胶凝胶法制备了PVA/(SiO2-TiO2)杂化纺丝液, 将其电纺成纤维膜. 红外光谱结果证实, PVA的羟基与TEOS和TBT水解后的羟基发生了缩合反应, 杂化电纺纤维膜以网络结构形式相结合; X射线衍射分析表明, 杂化电纺纤维膜的结晶度比纯PVA电纺纤维膜小; 扫描电镜表明, 随杂化纤维膜中无机相含量的增加, 纤维的直径不断增加, 纤维出现一定的弯曲和扭曲, 并伴有少量带状结构的纤维; 紫外-可见光谱结果表明, TiO2的引入增加了纤维膜的抗紫外性; TGA热分析结果表明, 杂化纤维膜的耐热性能优于纯PVA电纺纤维膜的; 耐水性和稳定性测试表明, 杂化纤维膜的耐水性和稳定性优于纯PVA和PVA/SiO2电纺纤维膜的.     

聚合物基纳米复合功能纤维材料研究进展北大核心CSCD

通过纳米材料与纤维基体的复合制备出聚合物基纳米复合材料,使其兼具纳米材料的功能性和聚合物的易加工性。本文综述了纳米复合阻燃纤维、纳米复合抗紫外纤维、纳米复合抗菌纤维和纳米复合导电纤维材料及纳米复合功能纤维的研究现状,包括纳米材料的改性、设计构筑及其复合聚合物、复合材料纺丝和功能性评价。提出未来聚合物基纳米复合纤维的几个主要发展方向:纳米材料的结构设计及可控制备与功能复合技术、成纤高聚物纳米改性技术,以及纳米复合纤维后整理加工技术;开发多功能复合产业用纤维,以及利用纳米技术开发战略性新兴产业用功能纤维;智能纤维的开发研究;纳米复合功能纤维及纺织品的生态安全性及系统评价。     

四氧化三铁中空/螺旋纤维的制备及形成机理

以柠檬酸铁为原料, 利用有机凝胶热分解法在低升温速率下热处理并还原制备了Fe3O4中空/螺旋纤维. 通过TG/DTA, XRD和SEM对前驱体纤维热分解过程、产物物相和形貌进行了表征. 结果表明, 产物主要由80%的中空纤维和20%的螺旋纤维组成, 其中中空纤维的直径为6 μm左右, 壁厚为500 nm. 螺旋纤维的直径为6~10 μm, 螺旋纤维是由具有不同旋向的宽度为4~6 μm的带状纤维卷曲而成, 带状纤维的外表面壳层均匀密实, 其厚度为600 nm左右, 而内层疏松且不规则. Fe3O4中空/螺旋纤维是由晶粒尺寸为60 nm左右的纳米颗粒构成, 并有少量的介孔. 分析了中空纤维和螺旋纤维的形成机理, 直径较小的前驱体纤维在热处理过程中内部凝胶向表层迁移收缩形成中空纤维; 螺旋纤维是由直径较大的前驱体纤维在热处理过程中产生的强大的热应力导致纤维产生螺旋破裂形成的.     

电纺聚乙烯醇超细纤维膜的性能研究

由电纺制备聚乙烯醇(PVA)超细纤维膜,以扫描电镜观察纤维的微观形貌,用X射线衍射研究超细纤维膜的结晶行为,并测定了PVA超细纤维膜的力学性能和吸水性.结果表明,PVA超细纤维的平均直径为(184±26)nm,超细纤维中PVA的结晶度和晶体有序程度较浇铸膜低.超细纤维膜的拉伸强度、模量和断裂伸长率均较浇铸膜差,吸水率在300%以上,高于浇铸膜.     

Separation of Water‐in‐Oil Emulsions Using Glass Fiber Media Augmented with Polymer Nanofibers

Water‐in‐oil emulsion separations are important to the petrochemical industry for product quality, safety, environmental, and economic reasons. Glass fiber filter media are often used to remove water droplets out of water‐in‐oil emulsions. The experimental results in this work show that 1% by mass of polyamide nanofibers with diameters of about 150 nm added to conventional micron‐sized glass fiber filter media improves the separation efficiency of the filter media from 71 to 84%. The addition of similar amounts of micron‐sized polyamide fibers to the glass fiber media do not improve filter capture efficiency.     

Simultaneous determination of airborne carbamates in workplace by high performance liquid chromatography with fluorescence detection

A high performance liquid chromatography with fluorescence (HPLC-F) detector was examined to simultaneous determination of airborne carbamates in the workplace of manufactory. The OVS-2 air sampling tube filled with glass fiber filter or quartz fiber and combined filter/XAD-2 were evaluated to collect nine commonly used carbamates (Carbofuran, Isoprocarb, Methomyl, Metolcarb, Thiodicarb, Carbaryl, Oxamyl, Methiocarb, and Prpoxur) from the air of manufactory in high humidity country. After being extracted with acetonitrile from sampling tubes, the carbamates were determined by high performance liquid chromatography with fluorescence detection posterior to on-line derivatization. The collection of carbamates and the recovery of extraction from glass wool fiber in several concentration levels, and from quartz filter were evaluated. The storage stability of carbamates was also tested. Results indicated that the HPLC-fluorescence method offers satisfactory resolution and sensitivity in carbamate analysis. With the glass fiber filter and combined filter/XAD-2, the Carbofuran, Isoprocarb, Methomyl, Metolcarb, and Thiodicarb were stable for a 28-day storage test, Carbaryl and Oxamyl for 14 days, and Methiocarb and Prpoxur for 7 days. All of these pesticides were with detection limit of 3 μg m⁻³. It is suited for environmental monitoring. The airborne carbamates in different areas of the manufactory were measured.     

The determination of lead in total suspended air particulates by x-ray fluorescence spectroscopy

A method has been developed for the measurement of lead in air particulates collected on glass fiber filter paper with wavelength-dispersive x-ray fluorescence spectroscopy (WDXRF). Analyses conducted by both WDXRF and an EPA-approved procedure that employs acid sonication followed by analysis of the extract by atomic-absorption spectroscopy (AAS) shows excellent agreement between the two methods. WDXRF calibration was accomplished with standards prepared from known additions of Pb to unexposed glass fiber filter discs. Method equivalency has also been demonstrated by the analysis of several reference materials and the statistical analysis of quality control data. The WDXRF procedure has also been used to evaluate the distribution of Pb in the particulates across the surface of the filter.     

Trapping of volatile iodine by an activated carbon fiber filter

Model experiments for a simple and effective trapping device of volatile iodine that is generated during radioiodination of biomacromolecules were performed using an activated carbon fiber filter. Over 99.9% of the radioactivity was trapped by the first sheet, when a stream of the volatile radioactive iodine was passed through the layer consisting of several sheets of carbon fiber filter of pore-size 2nm preceded by two or three sheets of urethane foam filter to eliminate the water vapor. Since the carbon fiber filter has very little resistance to the gas flow, the device seems applicable to the small filter chamber for the radioiodination hood.     

Effect of cellulose nanofiber dimensions on sheet forming through filtration

Four different cellulose nanofibers samples were prepared from northern bleached softwood kraft fibers. Fiber diameter distributions were measured from SEM images. Fiber aspect ratios ranging from 84 to 146 were estimated from fiber suspension sedimentation measurements. Three samples had heterogeneous distributions of fiber diameters, while one sample was more homogeneous. Sheet forming experiments using filters with pores ranging from 150 to 5 μm showed that the samples with a heterogeneous distribution of fiber dimensions could be easily formed into sheets at 0.2% initial solids concentration with all filter openings. On the other hand, sheets could only be formed from the homogenous sample by using 0.5% or more initial solids content and a lower applied vacuum and smaller filter openings. The forming data and estimated aspect ratios show reasonable agreement with the predictions of the crowding number and percolation theories for the connectivity and rigidity thresholds for fiber suspensions.     

Preparation and chromatographic behavior of acetate-fiber filter rods with dye affinity ligands

Summary The dyes cibacron blue F3GA and reactive red 120 have been immobilized on acetate fiber filter rods to produce potential affinity matrixes. The isothermal adsorption of bovine serum albumin or human serum albumin on these matrixes was investigated and proved to conform to the Freundlich equation. In the static adsorption of human plasma the adsorption capacity for human serum albumin was 12.5 mg g⁻¹ fiber filter and one band was observed in SDS-PAGE electrophoresis of human serum albumin isolated by the immobilized cibacron blue F3GA filter rod. Ligand utilization efficiencies and breakthrough volumes were obtained for adsorption of HSA on the cibacron blue F3GA filter rod when the feed-rates were from 0.5 to 6 mL min⁻¹. In the affinity chromatography of human plasma the yield of human serum albumin was 1.27 g per 100 mL plasma.     

Optimization of the Aerosol Filter Parameters

Theoretical approach to the optimization of the parameters of two-stage fibrous aerosol filter is reported. The approach is based on earlier developed method for the calculation of the clogging of model filter where the particle deposit is approximated by the porous shell on the fibers. The values of optimal fiber radii are determined from the condition of maximal dust capacity of a filter at given limiting pressure drop and total initial efficiency. Optimization was performed with allowance for possible variation in the prefilter thickness.     

顶空-气质联用法对醋酸纤维滤棒中溶剂残留的测定

利用顶空-气质联用仪(HS/GC-MS)建立了一种同时测定醋酸纤维滤棒中溶剂残留的测定方法.利用顶空气相色谱技术,用选择离子模式对醋酸纤维滤棒中溶剂残留进行了定量分析.分析结果表明,方法线性关系良好,相关系数均大于0.998 0,检出限为0.010 4~0.157 8 mg/kg.9种溶剂残留的平均回收率为90.3%~102.2%,相对平均偏差小于10%.方法适用于醋酸纤维滤棒溶剂残留的测定且高效、准确、简便.     

Effect of fiber orientation on fiber wetting processes

The current work incorporates a microscopic study of the effect of fiber orientation on the fiber wetting process and flow of liquid droplets along filter fibers when subjected to airflow and gravity forces. Glass filter fibers in various combinations were oriented at various angles within a plane defined by the airflow direction and were supplied with distilled water in aerosol form. The behavior and flow of the liquid collected by the fibers were observed and measured using a specially developed microscope cell, detailed in the paper. The experimental results were compared to a theoretical model developed to describe the behavior. The theory and experimental results showed good agreement. The developed theory allows an optimum angle to be determined for the internal filter fiber structure in the design of wet filters. A sensitivity analysis of the model was conducted to determine the most important parameters. This will aid design of wet filtration systems such that maximal self-cleaning can be accomplished with minimal water use.     

Filtration application from recycled expanded polystyrene

Water-in-oil emulsion with drop size less than 100 mum is difficult to separate. Coalescence filtration is economical and effective for separation of secondary dispersions. Coalescence performance depends on flow rate, bed depth, fiber surface properties, and drop size. The amount of surface area of the fibers directly affects the efficiency. A new recycling method was investigated in the previous work in which polystyrene (PS) sub-mum fibers were electro-spun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. The experimental results in this work show that adding nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media but also increases the pressure drop. An optimum in the performance occurs (significant increase in efficiency with minimal increase in pressure drop) with the addition of about 4% by mass of 500 nm diameter PS nanofibers to glass fibers for the filters.