AB-8大孔树脂对黄连解毒汤不同药物组合物理化学参数影响的初步研究

探索大孔树脂分离技术对中药复方不同药物组合物理化学参数的影响。以黄连解毒汤为实验体系,测定AB—8大孔树脂分离前后该复方不同药物组合原液及醇洗脱液的pH值、电导率、浊度、粘度等指标。黄连解毒汤不同药物组合在AB—8大孔树脂分离前后的pH值、电导率、浊度、粘度等方面表现出不同的变化。大孔树脂分离技术可改变中药复方不同药物组合的物理化学参数。     

50味常用中药挥发油的理化性质研究

通过考察50味常用中药挥发油的物理化学性质,建立其表征技术体系,探索中药挥发油物理化学性质的规律性。以水蒸气蒸馏法提取50味常用中药中的挥发油,测定其20、40、60~C时的浊度、粘度、电导率、盐度、pH值、密度、表面张力、折光率等指标。结果表明,中药挥发油一般均较澄清、粘度在0—10mPa·S之间,无盐度和电导率,pH值在3．353—6．654之间,为弱酸性,相对密度在0．8557～1．1516之间,表面张力在27．85—50．46N·cm。之间,折光率在1．4475—1．5987之间,这些物理化学参数随温度的变化存在一定的规律性。     

关于中药水提液的粘度特征及其与膜通量的相关性初步研究

研究中药水提液的粘度对无机陶瓷膜微滤中药水提液膜通量的影响及中药水提液在微滤前后粘度变化规律。制备约200种中药（单味及复方）水提液为实验体系,在温度、压力、膜面流速恒定的条件下分别过0．2μmZrO2无机陶瓷膜,测定不同中药水提液的膜稳定通量及微滤前原液、微滤后渗透液、截留液的粘度,并用SPSS对它们的相关性进行分析。结果表明中药水提液的粘度与膜稳定通量有很大的相关性,微滤后渗透液的粘度减小且不同水提液粘度差异性变小,截留液粘度增大、且截留液粘度、粘度变化率与原液粘度呈高度显著线形相关。粘度是影响无机陶瓷膜微滤中药水提液膜通量的关键因素,在中药膜污染的防治过程中可通过提取路线的设计或对药液进行预处理降低药液的粘度从而提高膜通量,减少膜污染。     

一种小型水库自洁净化装置及中试效果

针对部队指战员、野外施工作业人员的饮水安全需求,结合野外水处理装置的实际使用环境,确定了适宜的饮用水处理工艺;通过中试试验,优化各工艺参数,研制了一种小型机动水库自洁净化装置。在中试试验中,考察了处理前后色度、浊度、菌落总数、pH、电导率、TDS、溶解氧、总磷、COD_(Cr),温度、流量、压力等水质参数的变化。试验结果表明:一级装置及二级装置出水流量稳定,经过一级装置处理后,色度、浊度、COD_(Cr)、总磷及菌落总数均有明显下降,再经过二级装置处理后,色度、浊度及菌落总数进一步显著下降;而pH、电导率、TDS有微小变化。二级装置出水的色度、浊度、菌落总数、pH、电导率、TDS等水质参数能达到《生活饮用水卫生标准》(GB 5749—2006)的规定。所设计的水库自洁净化设备占地面积小,结构简单,便于机动作业,易于维护。     

异辛基乙二胺—辛酰基丙氨酸型质子化离子液体的合成及其吸收CO2的研究

由异辛基乙二胺(2-Ethyl-N-hexylethylenediamine,EtHexen)与辛酰基丙氨酸(Octanoylalanine,Octala)合成了鳌合胺型酰基氨基酸类新型质子化离子液体[HEtHex][Octala]。研究了其溶解性、热稳定性(T_d)、熔点(T_m)及吸收CO_2的能力。[HEtHex][Octala]极易溶于水,可达90 wt.%以上,其热分解温度为173.1℃,熔点为32.6℃。配制摩尔比分别为1∶10、1∶15、1∶20及1∶25的[HEtHex][Octala]/水体系,并在30℃下,测定了其吸收CO_2前后体系的pH值、密度(ρ)、粘度(η)及电导率(σ)值。结果显示:随着体系中水的摩尔比的增加,其pH值、密度、粘度值下降、电导率值增大;吸收CO_2后,与吸收CO_2前比较,体系的pH值和电导率降低,密度和粘度增大。     

全钒液流电池用SPEEK／PES共混膜的制备

通过将PES掺入高磺化度的SPEEK进行共混改性,采用流延法制备了一系列不同PES含量的SPEEK／PES共混膜,获得了SPEEK／PES共混膜的离子交换容、含水率、质子电导率等参数,特别测定了在全钒液流电池工作条件下钒（IV）离子渗透率。综合考察发现,当磺化温度为45℃,磺化时间控制为4h,得到SPEEK的DS为55％,掺入10％的PES,此时共混膜的电导率为0．08S／cm,钒（IV）离子渗透率为0．38×10^-6cm2／min,对钒（IV）离子选择性为Nation膜的5倍,含水率为35％,共混膜综合性能最好,基本满足全钒液流电池（VRB）的使用需求。     

不同季度渗滤液性质研究

用不同孔径的系列膜对不同季度渗滤液进行梯度分离。对分离前后渗滤液的COD、TOC、pH、TP、氨氮、正磷酸盐、色度、浊度和电导率等参数进行了测定，并建立了各参数与不同孔径膜的关系。结果表明：老港填埋场3月份渗滤液比6月份渗滤液污染性强，渗滤液的C：N：P的比分别为1168：232：1和1003：377：1，对于生物处理工艺来说，其C：N：P比例明显失调。同时发现：渗滤液的绝大部分污染物质集中于可溶性部分，而渗滤液中的P主要与大分子的悬浮物和粗胶体结合。在浊度与色度这两指标中，悬浮物和粗胶粒大约贡献一半左右。     

过滤分离技术应用于中药提取液的实验研究

针对中药提取液固液分离的特点,以野马追提取液为研究对象,测定了药液与过滤有关的基本物性,得到了药液的粘度—温度变化趋势以及药渣的比阻与可压缩性系数,表明药液的粘度随温度的变化较大;形成的滤饼具有高可压缩性,因此过滤压力不宜过高。通过10种纸板过滤性能的测定,筛选出适合于本药液的过滤介质;并通过对比过滤前后药液的有效成分,证明选择合适的过滤介质与加压过滤不仅能够明显降低药液中杂质含量,还能保证其有效成分在过滤后有较高的保留率。为减少药液存放后沉淀的析出,实验中还加入极少量允许添加的生物酶,减少了沉淀的析出。这些实验结果优化了野马追提取液的分离工艺操作参数,对其他中药提取液的澄清也有一定的借鉴作用。     

溴代十六烷基吡啶微乳液体系的电导行为研究

研究了pH值、温度、盐及其浓度变化对溴代十六烷基吡啶／正丁醇,苯／水微乳液体系电导率变化趋势的影响。结论表明,pH值对体系的电导率没有明显影响,50℃以上时,微乳液体系在碱性条件下比在酸性条件下稳定。当体系加入不同盐时,电导率随温度升高、盐浓度的增大而增大;同样条件下,硫酸钠体系的电导率要比氯化钠体系高。     

聚醚砜分子量对相转化法YSZ中空纤维陶瓷膜结构与性能的影响

采用不同分子量聚醚砜(PES)作为聚合物结合剂,通过相转化法和高温烧结制备了非对称结构YSZ中空纤维陶瓷膜。研究了不同分子量聚醚砜制备的铸膜浆料粘度变化对相转化过程及膜的微观结构与孔隙率和孔径、纯水和氮气渗透通量及抗弯强度等性能的影响。结果表明,采用分子量较小的PES制备的中空纤维膜由内侧大指孔结构和外侧小指孔结构构成。随着PES分子量和铸膜浆料粘度提高,外侧指孔长大而内侧指孔减小,且出现明显的中间海绵层。随着浆料粘度提高,膜孔隙率明显下降。采用PES E3010作为聚合物原料时,制备的YSZ中空纤维膜具有最大的外表皮层分离孔径,表现出最高的渗透性能和抗弯强度,在1400℃保温3 h烧结时,膜纯水通量和抗弯强度分别可达到9.35 m~3/(m~2·h·MPa)和113.9 MPa。     

Preparation of blend polyethersulfone/cellulose acetate/polyethylene glycol asymmetric membranes for oil–water separation

Blend PES/CA hydrophilic membranes were prepared via a phase-inversion process for oil–water separation. PEG-400 was introduced into the polymer solution in order to enhance phase-inversion and produce high permeability membranes. A gas permeation test was conducted to estimate mean pore size and surface porosity of the membranes. The membranes were characterized in terms of morphology, overall porosity, water contact angle, water flux and hydraulic resistance. A cross-flow separation system was used to evaluate oil–water separation performance of the membranes. From FESEM examination, the prepared PES/CA membrane presented thinner outer skin layer, higher surface porosity with larger pore sizes. The outer surface water contact angle of the prepared membrane significantly decreased when CA was added into the polymer solution. The higher water flux of the PES/CA membrane was related to the higher hydrophilicity and larger pore sizes of the membrane. From oil–water separation test, the PES/CA membrane showed stable oil rejection of 88 % and water flux of 27 l/m² s after 150 min of the operation. In conclusion, by controlling fabrication parameters a developed membrane structure with high hydrophilicity, high surface porosity and low resistance can be achieved to improve oil rejection and water productivity.     

Application of surface modifying macromolecules in polyethersulfone membranes: Influence on PES surface chemistry and physical properties

Novel surface modifying macromolecules (SMMs) were developed for incorporation into polyethersulfone (PES) membranes, intended for pervaporation applications. These materials were synthesized with a diisocyanate, polypropylene oxide (PPO), and a fluoro-alcohol, and characterized for elemental analysis, molecular weight, and glass transition temperatures. PES/SMM blends with eight types of SMMs were characterized for surface and physical properties and compared with PES. Water droplet contact angle measurements and X-ray photoelectron spectroscopy data showed that the SMMs migrated to the surface and rendered the PES material more hydrophobic. While advancing contact angle data were equivalent to those of pure Teflon™, the highest average values of receding angles of these systems were less than those of commercial Teflon™. The opaqueness of PES/SMMs films and data from differential scanning calorimetry experiments showed that the SMMs were either immiscible or only partially miscible with PES. It was also observed, for a fixed PES concentration of 25 wt %, that increases in the molecular weight of the SMMs and the weight fraction of PPO in the SMMs led to phase separation in the ternary PES/SMMs/dimethylacetamide (i.e., membrane casting solution) system. On the other hand, in the binary PES/SMMs system (i.e., cast membrane film), an increasing weight fraction of fluorine in the SMMs contributed to an increase in the phase separation. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1363–1378, 1999     

Influence of lithium chloride, lithium bromide and lithium fluoride additives on performance of polyethersulfone membranes and its application in the treatment of palm oil mill effluent

In this study three different types of lithium halides; lithium bromide (LiBr), lithium chloride (LiCl) and lithium fluoride (LiF) were used as additives in the making of polyethersulfone (PES) membranes. The concentration of PES is kept constant at 20 wt.% throughout the study, and the lithium halide concentration is varied in the range of 1-5 wt %. The solvent used is N, N-dimethylformamide and the PES asymmetric membrane was prepared by the dry/wet phase inversion process. Membrane performance was characterized in terms of pure water permeation (PWP), permeation rate (PR) and solute separation of polyethylene glycol (PEG) solution of various molecular weights ranging from 600 to 35,000 Da. The molecular weight cut off (MWCO) and mean pore size distribution were subsequently determined. Results revealed that the 3 wt.% LiBr exhibits the best performance with MWCO at 90% rejection in the range of 2.83 kDa and high flux range of 117.69 L m^− 2 h^− 1. Hollow fibers spun from the dope solutions containing LiBr revealed that they are capable of treating palm oil mill effluent (POME) with reduction in turbidity, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of 96.7%, 53.12% and 76.7% respectively.     

Electrospun nanofibrous polyvinylidene fluoride-co-hexafluoropropylene membranes for oil–water separation

Effective separation of oil from water is of significant importance globally for various applications such as wastewater treatment, oil spill cleanup, and oil purification. Among the numerous approaches for oil removal, membrane separation is considered one of the most promising approaches due to its selectivity and ease of operation. Electrospinning is a promising technique for producing polymeric membranes with tunable structures with interconnected pores, large surface area, and high porosity. In this study, hydrophobic poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibrous membranes were electrospun and used for this purpose. The effects of various parameters (e.g., polymer concentration, applied voltage, tip to collector distance, and feed rate) were investigated to find the optimum electrospinning conditions. Further, the electrospun membranes were characterized according to average fiber diameter, morphology, average pore size, and wettability to identify the combinations most likely to succeed in oil–water filtration. The physical–chemical properties of the membranes (i.e., thickness, areal density, porosity, average pore size, water/oil contact angle, hydrostatic pressure head, and oil filtration flux) were studied based on standard test methods. The separation efficiency of eight electrospun membranes with various pore sizes and average fiber diameters were tested for diesel/water mixtures. A linear relation was found between the initial oil flux and the average pore size of the membranes. The maximum oil filtration flux of about 224 L/m²/h, achieving over 75% oil recovery in 10 min, was obtained for the electrospun membrane with the average pore size of 4.5 μm. The membranes were successfully used for eight consecutive oil–water separation cycles without noticeable loss of flux.     

膜分离中有机物的特性对去除率的影响研究

试验采用ESNA1-2012纳滤膜和ESPA1-2012反渗透膜对有机物进行了分离研究,研究结果表明,在膜分离过程中影响有机物去除率的因素较多,其中有机物的本身特性对其去除率的影响极大;有机物的物理化学特征参数影响是膜与有机物间排斥力的作用,而有机物分子量的相对大小影响则是膜孔机械截留作用的大小。当有机物的分子量小于膜的截留分子量时,有机物的物理化学特征参数成为影响其去除率的主要因素;当有机物的分子量大于膜的截留分子量时,有机物的分子量与其物理化学特征参数共同成为影响其去除率的主要因素。     

Development of novel surface modified phase inversion membranes having hydrophobic surface-modifying macromolecule (nSMM) for vacuum membrane distillation

Eleven PES membranes, into which newly synthesized surface-modifying macromolecule (nSMM) was incorporated, were prepared by using the ‘phase inversion technique’ with different preparation conditions to find the effects of membrane casting parameters on the characteristics and performances of the surface modified PES membranes. The membranes so prepared were characterized by solute separation data from ultrafiltration experiments. The results showed that the mean pore size as well as the surface hydrophobicity increased with an increase in evaporation time for the casting solution blended with nSMM (without PVP). When PVP was added into the casting solution, the mean pore size as well as the contact angle decreased while the pure water permeation flux increased. The surface hydrophobicity decreased with an increase in gelation bath temperature.Four membranes were further prepared and subjected to vacuum membrane distillation (VMD). They were characterized by different analytical instruments and pure water permeation test before being used to VMD. The results showed that a distinctive surface layer was formed in nSMM blended PES membranes. It was also found that nSMM blended PES membranes were sufficiently hydrophobic and porous to be used for the separation of an ethanol/water mixture.     

Polyethersulfone composite hollow-fiber membrane prepared by in-situ growth of silica with highly improved oily wastewater separation performance

In order to reduce surface aggregation and enhance the performance of PES membranes, a hydrophilic PES/TEOS HF membrane was developed for the treatment of wastewater containing oil. PES/TEOS was prepared via a sol-gel self assembly and dry–wet spinning method. Silicon dioxide sol was prepared from a mixture of tetraethoxysilane, ethanol, water, and acetic acid (acting as the catalyst). HF hybrid membranes were produced from dope solutions containing polyethersulfone, polyethylene glycol, silicon sol, and NMP. The membranes were characterized by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), porosity, fourier transform infrared spectroscopy (FTIR), and contact angle measurements. The composite membranes were successfully used to treat wastewater containing oil and their separation performance were evaluated. The PES/TEOS-2 membrane displayed the best performance, with a permeate flux of 90.937 L/m² h and an oil retention of 99.98%. In addition, this membrane showed a higher pure water flux of 102.43 L/m² h as compared to PES-0 and PES/SiO₂–1 membranes (87.347 L/m² h and 91.949 L/m² h, respectively). The PES/TEOS-2 membrane also presented enhanced antifouling behavior with a FRR and a RFR of 93.33% and 11.22%, respectively. In addition, this membrane displayed excellent long-term recycling properties, making it a desirable candidate for oily wastewater separation applications.     

Comparative analysis of the processes of collagen concentration by ultrafiltration using different types of membranes

Tangential flow filtration of the collagen protein solutions with a molecular weight 12, 14, and 24 kDa is investigated using flat sheet membranes. The effects of tangential ultrafiltration (UF) on the permeate properties using two regenerated celluloses (RCs) and two polyethersulfone (PES) membranes with molecular weight cut-off (MWCO) of 5 and 10 kDa are reported. The permeate and concentrate obtained in the UF experiments are characterized from a physical–chemical point of view by determining the temperature, pH, electrical conductivity, nitrogen content, and protein concentration. In addition, the experimental data are modeled using Hermia's model. The UF experiments demonstrated that permeate flux declined with increasing molecular weight of collagen at constant concentration (1%). Regardless of the molecular weight of collagen, the rejections decrease in the following order: PES 5 kDa > RC5kDa > RC10kDa > PES10kDa. In case of membrane with higher MWCO, the clogging phenomenon is mainly due to the blockage of the internal pores of the membrane than the formation of a polarization layer. Morphologies and characteristics of the membranes are characterized using scanning electron microscopy.     

Influence of Oil Properties on Bed Coalescence Efficiency

Abstract

Bed coalescence efficiency of oil separation from formation water was studied on model systems involving 10 real samples of crude oil and its fractions of different characteristics. Oil components were varied and all other parameters were kept constant, and high mineralization water served as the continuous phase. All experiments were realized on a commercial WO/O4 two-stage bed coalescer. Temperature, oil content, and fluid velocity were kept constant for all samples. Model emulsion was dispersed by constant stirring during the experiment to obtain primarily droplets of 20 μm diameter. Correlations for predicting the coalescence efficiency as a function of some physical and chemical oil properties are presented. The investigated oil components ensured a wide span of viscosity, density, and interfacial tension. The influences of mean molecular weight, neutralization number, as well as the contents of n-alkenes, NSO, and aromatics on coalescence efficiency were analyzed. On the basis of the empirical dependences of coalescence efficiency on individual parameters obtained by regression analysis of the data, a general mathematical model was established.     

Effects of casting solution composition on performance of poly(ether sulfone) membrane

Flat-type poly(ether sulfone) (PES) membranes for ultrafiltration were prepared by the traditional phase-inversion technique. The effects of the concentration of PES and the combination of two solvents, dichloromethane (DCM) and N-methyl-2-pyrrolidone (NMP), with differences in volatility and solvating power on membrane performance were examined in terms of pure water flux (PWF) and solute rejection (SR) against poly(ethylene glycol) (PEG, MW 20,000). Changing the thermodynamic quality of PES/NMP casting solution by combining DCM, a volatile and weak solvent, affected the PWF of the resulting membrane. The SR of PES/DCM–NMP membrane, however, was more likely dependent upon the effect of evaporating the volatile solvent from the casting solution/air interface rather than the effect of changing the thermodynamic quality of the casting solution. Combining DCM in PES/NMP casting solution transformed the fingerlike macrovoids of PES/NMP membrane prepared without DCM into the isolated macrovoids. PES/DCM–NMP membrane prepared with PVP, a water soluble poreforming agent, showed an increased PWF while maintaining SR of over 90%, even under the reduced feeding pressure of 1 kg/cm². It is necessary to measure molecular weight cutoff of membrane for demonstrating the potential of PVP for improving the membrane permeability without losing the selectivity.© 1996 John Wiley & Sons, Inc.