Effect of Heat Treatment on Structures and Properties of Polyurethane Blend Ultrafiltration Membranes

The polyurethane/polyacrylonitrile (PU/PAN) and polyurethane/cellulose acetate (PU/CA) blend ultra filtration membranes were prepared based on Loeb-Sourirajan phase transition method. The change of the structures and properties of the PU/PAN and PU/CA membranes with the heat treatment process was studied. The results showed: the water flux decreased and retention increased with the increase of heat treatment temperature of PU/PAN blend membrane, but the water flux of PU/CA blend membrane got the maximum with heat treatment temperature of 60℃ and decreased rapidly with the heat treatment temperature of 100 ℃. The interfacial microvoid structure and its influence on the properties of PU/PAN and PU/CA blend membranes were studied.

Changes of Resistance During Polyelectrolyte-enhanced Stirred Batch Ultrafiltration

The permeation flux or the resistance in the ultrafiltration process is mainly limited by osmotic pressure, and it may originate from various kinds of polymer interactions. However, the real origin of permeation resistance hasn＇t been clarified yet in the light of polymer solution nature. The removal of nitrate contamination by polyelectrolytes was carried out with stirred batch ultrafiltration. The polyelectrolyte concentrations both in permeate and retentate were analyzed with total organic carbon analyzer and permeate mass was acquired by electronic balance connected with computer. The total resistance was calculated and interpreted based on the osmotic pressures in three concentration regimes. In the dilute region, the resistance was proportional to polymer concentration; in the semidilute region, the resistance depended on polymer concentration in the parabolic relationship; in the highly concentrated solution regime, the osmotic pressure factor （OPF） would dominate the total resistance; and the deviation from OPF control could come from the electrostatic repulsion between the tightly compacted and charged polyelectrolyte particles at extremely concentrated solution regime. It was first found that dilute and semidilute concentration regions can be easily detected by plotting the leg-log curves of the polymer concentration versus the ratio of the total resistance to polymer concentration. The new concept OPF was defined and did work well at highly concentrated regime.

Highly Reversible Li–Se Batteries with Ultra-Lightweight N,S-Codoped Graphene Blocking Layer

The desire for practical utilization of rechargeable lithium batteries with high energy density has motivated attempts to develop new electrode materials and battery systems. Here, without additional binders we present a simple vacuum filtration method to synthesize nitrogen and sulfur codoped graphene(N,S-G) blocking layer, which is ultra-lightweight, conductive, and free standing. When the N,S-G membrane was inserted between the catholyte and separator, the lithium–selenium(Li–Se)batteries exhibited a high reversible discharge capacity of 330.7 mAh g^(-1) at 1 C(1 C = 675 mA g^(-1)) after 500 cycles and high rate performance(over 310 mAh g^(-1) at 4 C) even at an active material loading as high as ～5 mg cm^(-2). This excellent performance can be ascribed to homogenous dispersion of the liquid active material in the electrode, good Li^+-ion conductivity, fast electronic transport in the conductive graphene framework, andstrong chemical confinement of polyselenides by nitrogen and sulfur atoms. More importantly, it is a promising strategy for enhancing the energy density of Li–Se batteries by using the catholyte with a lightweight heteroatom doping carbon matrix.

超长滤袋局部加密对滤袋表面过滤风速分布的影响

针对超长滤袋表面过滤风速沿其轴向分布极为不均的问题,采用数值模拟方法探究了超长滤袋局部加密对滤袋表面过滤风速分布的影响,为提升超长滤袋袋式除尘器的过滤性能寻求解决方法。结果表明:当超长滤袋未进行局部加密时,滤袋表面过滤风速沿其轴向自上而下呈递减趋势,最大过滤风速高达3.18 m/min(设计过滤风速为1.0 m/min),对应过滤风速分布均匀性指数为0.122,过滤风速分布极不均匀,此时滤袋顶部受到高速气流的冲刷作用明显;当对超长滤袋顶部30%长度滤袋进行局部加密后,滤袋表面过滤风速分布均匀性得到显著提升;当局部加密孔隙率由85%降至60%时,滤袋表面过滤风速分布均匀性指数由0.037先增至0.518后降至0.434,对应除尘效率并不受影响;当局部加密孔隙率取值为65%时,滤袋表面最大过滤风速降至2.1 m/min,此时过滤风速分布均匀性指数达到最大值0.518。

超长滤袋排气管结构对滤袋特性影响数值研究

滤袋表面过滤风速轴向分布不均会导致滤袋上部过早损坏,这一问题对于超长滤袋而言更为突出,为改善超长滤袋表面过滤风速的均匀性,针对典型10 m超长滤袋(设计过滤风速为1.0 m/min)采用袋口增设一段内伸排气管方式以改善滤袋内部流场结构。研究结果表明:当增设内伸排气管结构时可以大幅改善滤袋表面过滤风速的均匀性,存在最优的排气管内伸长度和直径的组合可改善超长滤袋过滤特性;当排气管内伸长度为滤袋长度的一半时滤袋表面过滤风速的均匀性最好;增加排气管直径会降低除尘器运行压降;综合考虑运行压降和滤袋表面轴向速度,当排气管内伸长度为滤袋长度的0.2倍,直径为滤袋直径的0.8倍时可以提升约30%的过滤风速表面分布均匀性,此时除尘器的运行压降下降0.65%,滤袋表面轴向速度峰值增加7.75%。

无黏土水基钻井液用超支化聚合物降滤失剂的合成及性能评价

在高温条件下,聚丙烯酰胺类降滤失剂分子易发生降解,导致降滤失效果大幅下降。为此,通过超支化单体季戊四醇三烯丙基醚(APE)与2-丙烯酰胺-2-甲基丙磺酸(AMPS)、丙烯酰胺(AM)、对苯乙烯磺酸钠(SSS)共聚合成了一种耐高温的超支化聚合物降滤失剂JHPAS,以JHPAS为基础配制了一种新型的无黏土水基钻井液,分析其降滤失机理,评价其在高温、高盐条件下的流变性能和降滤失性能。结果表明:JHPAS具有很好的热稳定性,在水溶液中可形成网络结构,在无黏土水基钻井液中吸附于超细CaCO 3表面形成致密滤饼,并堵塞滤饼上的孔隙,进一步降低钻井液滤失量;构筑的无黏土水基钻井液在200℃老化16 h、饱和氯化钠盐水的条件下仍具有稳定的流变性和良好的降滤失性能,API滤失量和高温高压滤失量分别为5.5 mL和7.6 mL。研究成果有助于推动超支化聚合物在深层、超深层油藏钻井液中的研究与应用。

超短半径水平井双保型醇基钻井液技术

针对超短半径侧钻水平井面临的井眼尺寸小、井眼曲率大、管柱通过能力受限等问题,通过研选聚合醇类处理剂为核心处理剂,利用其浊点效应,达到抑制、润滑、环保的效果,实现一剂多效,再辅以自研增黏降滤失剂、环保润滑剂等关键处理剂,利用侧钻井井筒内油田水配制钻井液,形成了双保型醇基钻井液技术。通过室内评价实验,双保型醇基钻井液能够抗20%岩屑污染,极压润滑系数达到0.088,滚动回收率为93.4%,生物毒性指标大于106 mg/L,生物降解指标18.16%,为无毒可降解体系,动态渗透率恢复值为91.32%~92.56%,具有较好的储层保护性能。2021年至今,该双保型醇基钻井液技术在大庆油田35口超短半径侧钻水平井应用,累计利用油田水2000 m^(3),减少2000 m^(3)油田水和1200 m^(3)废弃钻井液的排放,节约废弃钻井液处理费用25万元,达到了节能环保的目标,为老井剩余资源高效开发提供了技术支撑。

Protection of Ultra-filtration Extract from Danggui Buxue Decoction(当归补血汤) on Oxidative Damage in Cardiomyocytes of Neonatal Rats and Its Mechanism

Objective： To investigate whether the administration of the ultra-filtration extract from Danggui Buxue Decoction （当归补血汤, EDBD） was able to protect cardiomyocytes from oxidative injury of rats induced by hydrogen peroxide （H2O2） and its potential mechanism. Methods： Myocardial cells from 1- to 2-day-old neonatal rats were cultured in Dulbecco＇s modified Eagle＇s medium low-glucose and Ham＇s F12 medium （1：1）, and the cellular injury was induced by H2O2. The ultra-filtration extract mixture from Angelica sinensis and Hedysarurn po/ybotrys was given in three doses of 3.75, 7.5, and 15 mg/mL. Morphological changes of cardiomyocytes were observed by microscope. Survival rate of myocardial cells was assessed using 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （Ml-r） assay. The cardiomyocyte damages were estimated by detecting lactate dehydrogenase （LDH） and creatine kinase （CK） releases in the medium, superoxide dismutase （SOD） activities, and intracellular malondialdehyde （MDA） and myeloperoxidase （MPO） contents. The levels of caspase-3 and heat shock protein 70 （hsp70） mRNA expression in cardiomyocytes were measured by reverse transcription polymerase chain reaction. Results： The EDBD could protect the cardiomyocytes from H202 injury in a dose- dependent manner （3.75, 7.50, and 15.00 mg/mL）. The EDBD could significantly decrease LDH and CK leakages and intracellular MDA and MPO contents, increase SOD activity, up-regulate hsp70 expression, and down-regulate caspase-3 expression. Conclusion： The EDBD has protection on cardiomyocytes injured by H202 through improving cell antioxidant ability, up-regulating hsp70 expression, and inhibiting caspase-3 activity.

甘蔗原汁制备转化糖浆前处理工艺研究

以甘蔗原汁为原料,通过微/超滤、活性炭吸附及离子交换树脂吸附依次处理甘蔗原汁,以蔗汁色值、混浊度及电导灰分为考察指标,通过单因素试验、正交试验优化处理工艺。结果表明:最佳过滤孔径为0.05μm;活性炭吸附最佳工艺条件为活性炭添加量0.5%(以微/超滤处理后的蔗汁质量为基准)、吸附温度90℃、吸附时间20 min、pH 5.0。离子交换树脂吸附最佳工艺条件为糖液与树脂质量比1∶1、吸附温度70℃、吸附时间60 min、pH 5.0,在此工艺条件下,所得蔗汁色值为(26±6)IU,混浊度为(16±6)MAU,电导灰分为3.29%±0.034%,蔗汁品质佳。

焦作矿区煤泥超高压压滤脱水系统的优化与应用

为解决焦作矿区煤泥产量大、水分高、热值低、销售难等问题,焦作煤业(集团)有限责任公司以中马村矿选煤厂为试点,先后在该矿区建设了14套煤泥超高压压滤系统。文章介绍了超高压压滤的工艺、主要设备选型及布置方案,并通过对压滤入料粒度组成、入料浓度、给料压力、压榨压力等参数的分析及优化,确定了最佳压滤操作参数。参数分析结果表明:压滤入料中>0.5 mm粒级物料易堵塞入料软管或聚集在滤板凸台区域而损坏滤布,应尽量减少;压滤上料时间随着入料浓度、给料压力的增加而减少,二者最佳值分别550 g/L和1.1 MPa;压滤煤泥水分随压榨压力的增大而减小,各矿压榨压力最佳值不同,可根据生产需要加以调整。影响因素优化后生产实践表明:煤泥超高压压滤系统运行稳定,自动化和智能化水平高;压滤周期显著降低至70 min左右,有效提高了生产效率;煤泥水分则可降至14.5%左右,发热量平均提高约2.84 MJ/kg,降水提质效果良好;煤泥经破碎后能够直接销售或掺配至电煤销售,每年可新增经济效益7740.82万元,实现了煤泥无量化生产,经济效益及社会效益均较为显著。

Ceramic Ultra Filtration Membrane Bioreactor for Domestic Wastewater Treatment

A long term domestic wastewater treatment experiment was conducted using a recirculating ceramic ultra filtration membrane bioreactor (CUFMB) system. Three experiments were run with a hydraulic retention time of 5h, sludge retention times of 5d, 15d, and 30d and a membrane surface flow rate of 4m/s. The experiment studied the membrane fouling mechanism and cleaning techniques. The results show that a CUFMB system can provide continuous good quality effluent which is completely acceptable for reuse. The system is also not affected by fluctuations of the inlet flow. The CUFMB sludge loading rate is similar to that of conventional biological treatment units. However, the volumetric loading rate of the CUFMB is 24 times that of conventional biological treatment units. Membrane fouling occurs due to channel clogging, which could be easily removed, and surface fouling, which can be effectively removed using the method described in this work which includes water rinsing, base cleaning, and acid washing.

An approximate analytical solution to the ultrafiltration profile in a hemodialysis process between parallel porous plates

In a hemodialysis process,the blood that runs through straight channels exchanges substances with the dialysate through a semi-permeable membrane.The waste products,such as urea and creatinine,are therefore removed from the plasma by the membrane.In the analysis of this process,determination of the ultra-filtration profile along the porous membrane surface remains a difficult problem.In this work,an analytical solution to the derivation of such a profile was detailed,and the feasibility of this solution was discussed.The ultra-filtration profile was found to be in a cosine shape.

超滤技术应用对中药成分的影响

目的 研究各材质超滤膜对不同中药成分的影响 ,探索各类成分所适用的超滤膜。方法 以成分分析为指标 ,测定了 10种常用中药超滤前后药液的成分变化 ,以中药的超滤的透过率解析超滤膜材质、孔径与中药各类成分之间的关系。结果 超滤法对有机酸类及各苷类成分影响较小 ,对混悬液成分影响明显。生物碱类成分对膜超滤有较强的选择性。结论 水溶性较大的成分可适用于超滤 ,而极性小的成分损失较大 ;

超低渗透钻井液完井液技术研究

介绍了零滤失井眼稳定剂及超低渗透钻井液完井液的组成。在水基、油基钻井液中加入一定量的零滤失井眼稳定剂可以形成超低渗透钻井液。对加入一定量零滤失井眼稳定剂钻井液的API滤失量、高温高压滤失量、砂床滤失量、高温高压砂床滤失量、岩心滤失量、岩心承压能力、封堵裂缝效果和岩心渗透率恢复值的变化进行了评价。实验结果表明,超低渗透钻井液的砂床滤失量不是时间平方根的函数,与API滤失量没有对应关系;超低渗透钻井液对不同孔隙的砂床、岩心和裂缝具有很好的封堵能力,可以实现零滤失;零滤失井眼稳定剂可以防漏堵漏;通过增强内泥饼封堵强度大幅度提高了岩心承压能力;能有效保护储层,岩心渗透率恢复值大于95%。

苹果酒超滤澄清工艺的响应面法优化

为了改善苹果酒的澄清度和稳定性,采用超滤技术进行澄清。在单因素试验的基础上,采用Box-Behnken响应曲面法对影响苹果酒超滤的关键因素操作压力、温度和进料流速进行优化探讨。结果表明:3个因素对苹果酒澄清的影响大小依次为温度、操作压力、流速;澄清苹果酒最佳工艺条件为压力0.7 MPa,温度24℃,进料流速5.6 mL/min。超滤处理后,苹果酒的透光率为98.72%,膜通量为14.38 L/(m2·h),原酒的固有滋味和品质得到了较好保留。

典型南方水源溶解性有机物分子量分布变化及去除特性

用超滤膜法对以东江为水源的深圳水库水体溶解性有机物（DOM）进行物理分级表征，研究了2005年3-9月原水中DOM分子量分布的连续变化特性，以及各分子量范围的DOM组分与消毒副产物三卤甲烷生成势（THMFP）之间的关系．结果表明，在此原水DOM中，相对分子量小于1000的有机物所占比例最高（平均值为41．15％（以DOC计）），这说明东江原水中DOM主要以小分子量有机物为主，此分子量范围有机物所产生的THMFP在原水中所占比例均值为32．23％．水处理研究表明，常规工艺和深度处理工艺对其DOC和THMFP的去除率均不高．对原水总DOC的贡献占第二位的是分子量在10^4-3×10^4之间的有机物（均值为24．07％），其对总THMFP的贡献率为29．09％。常规工艺对此分子量范围有机物去除效果很好．

超滤技术在单胞藻浓缩中的应用

利用超滤技术浓缩单胞藻 ,易于冷冻干燥及保存 ,提高劳动生产率 ,增加产量满足工业化要求。本实验选用板框式超滤器方法进行单胞藻浓缩实验 ,主要包括超滤膜规格的筛选 ,浓缩实验 ,滤膜的清洗等 ,结果表明经超滤处理后单胞藻浓度可达每毫升24×108个 ,冷藏存放3个月后 ,对脂肪酸组分及含量进行分析 ,并再接种培养和成活率检测 ,结果良好。

活性炭与超滤组合工艺深度处理饮用水

在北京燕山石化总厂利用活性炭吸附与超滤膜组合系统进行了为期一年的饮用水深度净化中试研究 ,结果表明 ,该系统能有效地去除水中的浊度、高锰酸盐指数、UV2 54和大肠杆菌。尤其是淹没式超滤膜组件有效地减少了出水中腐殖酸和富敏酸含量 ,其去除率平均为 4 0 % ,从而有效减少了消毒副产物量。

膜技术分离七叶参皂甙研究

以七叶参为材料,研究了微滤澄清、超滤除大分子、纳滤分离、纳滤浓缩等膜技术在分离七叶参皂甙的应用效果。结果表明,采用0.2μm微滤膜在40℃条件下微滤经粗滤后的七叶参浸提液,且在微滤滤液达到浸提液重的80%时加入与原料等重的透析水透析残渣可作为微滤澄清的技术参数;选用截留分子量为10000Da的超滤膜能有效去除色素等大分子物质;利用截留分子量为2500Da或3500Da的纳滤膜分离七叶参皂甙,可制得纯度为42%以上的七叶参皂甙产品,且3500Da纳滤膜比2500Da纳滤膜的得率要高,但干粉中皂甙纯度略低;选用500D的纳滤膜在32℃左右、操作压力为1.8MPa的条件下浓缩七叶参皂甙不仅浓缩效率高,而且可进一步提高产品纯度。

含油废水处理研究

简要概述了含油废水的特征,介绍了盐析法、絮凝法、电解法、吸附法、浮选法等常规处理含油废水方法及其相应的不足之处,同时介绍了四个处理含油废水的典型流程,并指出了这些传统处理流程的特点及不足之处,重点介绍了微滤、超滤和反渗透等膜分离技术处理含油废水的研究及进展,最后综合阐述了膜分离技术处理含油废水的优点,并指出膜分离技术处理含油废水的研究方向。