Demulsification Behavior, Characteristics, and Performance of Surfactant Stabilized Oil-in-Water Emulsion under Bidirectional Pulsed Electric Field

As a novel electric demulsification method,bidirectional pulsed electric field(BPEF)was employed to demulsify the surfactant stabilized oil-in-water(SSO/W)emulsion for oil/water separation in this work.The demulsification behavior,characteristics,and stages under BPEF were explored.It was discovered that BPEF drove SSO/W emulsion to move and form vortexes,during which the oil droplets aggregated and accumulated to generate an oil droplet layer(ODL).ODL subsequently transformed into a continuous oil layer(COL)leading to the demulsification and separation of SSO/W emulsion.The conversion rate of ODL to COL was defined and used to evaluate the demulsification process and reflect the coalescence ability and transformation efficiency of dispersed oil droplets into COL.Furthermore,the effects of BPEF voltage,frequency,duty cycle,ratio of pulse output time,and surfactant type and content on the demulsification performance were examined.The optimal values of BPEF parameters for demulsification operation were 400 V,25 Hz,50%,and 4:1.O/W emulsion containing anionic surfactant was apt to be demulsified by BPEF,nonionic surfactant took the second place and cationic surfactant was the most difficult.A high surfactant content was not conducive to the BPEF demulsification.This work is anticipated to provide useful guidance for oil/water separation and oil recovery from actual emulsified oily wastewater by BPEF.

Demulsification of Emulsion Liquid Membrane by Wetting Coalescence Materials

Demulsification of emulsified water-in-oil droplets was worked out with the employment of wetting coalescence materials. Demulsification is carried out in conventional stirred-column and packed-column. Among the four kinds of natural fibers and two kinds of inorganic materials tested, natural fiber A, originated from wood shavings was found to give the best performance of demulsification. The demulsification efficiency can exceed 96.5% when demulsification conditions are optimized. The packed-column showed much better performance both in terms of demulsification efficiency and repeated use of the recovered oil phase for extracting cadmium in simulated wastewater. Operating variables governing the demulsification efficiency were investigated.

Demulsification of Water in oil Emulsion by Using Porous Glass Membrane

The hydrophilic porous glass membranes were used to demulsify water in oil emulsion, liquid membrane and demulsification efficiency can reach more than 96 percent. Effects of pore size of the membrane, transmembrane pressure and volumetric ratio of oil phase to internal aqueous phase in the emulsion on demulsification were investigated. Correspondingly, effect of transmembrane pressure on permeation flux of the droplets was also studied.

Research and practice on the vacuum filter in emulsion system for tandem cold strip mill

This paper introduces working principle and technical features of vacuum filter in emulsion system for tandem cold strip mill.Based on specific cases,this paper analyses and assesses the effect before and after using the emulsion system with the usage of the vacuum filter for strip mill.Compare with the effect when using the first generation vacuum filter,the emulsion quality is improved significantly by using the second generation vacuum filter,which at the same time ensures steady operation of the rolling mill and surface quality of the mill products. As a result,investment and running costs are lowered,emissions of the waste emulsion are reduced,waste water treatment costs are reduced and so as the environmental pollution.It can be seen the second generation vacuum filter has obvious economic and environmental benefits.Therefor,it suggests that the filter should be used widely in the field of automotive,environmental protection rolling steel and nonferrous metals.

Coupling magnetic particles with flocculants to enhance demulsification and separation of waste cutting emulsion for engineering applications

Magnetic particles were coupled with a flocculant to enhance the demulsification and separation of waste cutting emulsions.The optimal magnetic particle size and critical magnetic field conditions were investigated to achieve large-scale engineering application of magnetic demulsification separation for waste cutting emulsion treatment.The micro-scale magnetic particles were found to show comparable effects to nano-scale magnetic particles on enhancing the demulsification and separation of cutting emulsions,which are beneficial for broadening the selectivity of low-cost magnetic particles.The critical magnetic separation region was determined to be an area 40 mm from the magnetic field source.Compared to the flocculant demulsification,the magnetic demulsification separation exhibited a significant advantage in accelerating flocs-water separation by decreasing the separation time of flocs from 180-240 min to less than 15 min,compressing the flocs by reducing the floc volume ratio from 60%-90%to lower than 20%,and showing excellent adaptability to the variable properties of waste cutting emulsions.Coupled with the design of the magnetic disk separator,continuous demulsification separation of the waste cutting emulsion was achieved at 1.0 t/hr for at least 10 hr to obtain clear effluent with 81%chemical oxygen demand removal and 89%turbidity reduction.This study demonstrates the feasibility of applying magnetic demulsification separation to large-scale continuous treatment of waste emulsion.Moreover,it addresses the flocs-water separation problems that occur in practical flocculant demulsification engineering applications.

A NOVEL METHOD OF BREAKING WATER-IN-OIL EMULSIONS BY USING MICROPOROUS MEMBRANE

A novel method for breaking emulsions with microporous membranes is presented.A membrane would act as a coalescer if its pore size is smaller than the emulsion droplets and if the dispersed phase has great affinity to the membrane.It was observed that a hydrophilic membrane is able to break water in oil emulsions with high separation efficiency.Effects of the membrane pore size,membrane thickness,transmembrane pressure and emulsion composition on demulsification performance were investigated.It was found that the membrane pore size and transmembrane pressure affect demulsification performance remarkably while other factors have slight or almost no effect.

Formation,stabilization and chemical demulsification of crude oil-in-water emulsions:A review

The crude oil recovery process is frequently associated with the formation of stable emulsions due to factors such as turbulent flow in pipelines and the presence of surface-active substances that naturally occur in crude oil.These emulsions are undesirable for the petroleum industry because their destruction/treatment adds to the overall production cost and causes the loss of valuable amounts of crude oil.Therefore,it is essential,for economic and environmental reasons,to optimize the crude oil demulsification process.The effective treatment of crude oil emulsions requires understanding of the process and factors leading to their formation and stabilization.In this sense,suitable treatment methods and possible preventive measures to avoid their formation can be employed.The present study reviews recent oilfield emulsion types and the factors responsible for their formation and stabilization.The different demulsification techniques employed were then extensively examined.Demulsification tech-niques include mechanical,thermal,electrical,and chemical methods with different demulsification mechanisms affected by many factors such as emulsions type and properties,demulsifiers characteris-tics,presence of solids stabilized emulsions,etc.The demulsification efficiency depends on the operating parameters of the process,the economics involved,and the environmental impact,which are the main factors considered in selecting a suitable demulsification technique.Future research on the demulsifi-cation of crude oil emulsions should focus on real crude oil emulsions studies at a pilot scale level,the effect of aging on crude oil emulsions,the combination of multiple demulsification techniques and their synergistic effects,and the use of natural,ecofriendly demulsifiers.

Emulsion Polymerization of P (MMA-AA-EA) and Its Demulsifying Performance in Water/Oil Emulsion

Stable water-in-oil emulsions are produced in oil exploitation and cause many environmental and operational issues.In this paper,a co-polymer demulsifier is reported in detail;an emulsion polymerization method is used to prepare nano-P(MMA-AA-EA)with MMA,AA and EA as the monomers,DVB as the cross-linker and APS as the initiator.The resulting products are characterized by FT-IR.Furthermore,the surface tension and particles size analysis is investigated.The results show that the surface tension reduction is 10.66 mN/m at 20?C when the concentration of co-polymer is 1000 ppm and the average size is 76.99 nm.Moreover,the HLB of polymer is discussed specifically by changing the amount of AA.With the increase of AA,the HLB value of the polymer is increased accordingly.Besides,the demulsification performance of the co-polymer is also evaluated at different synthesis and demulsification conditions.It is showed that the maximum demulsification efficiency is 96%at 70?C for 60 min.The optimum concentration of demulsifier is 400 ppm when the amounts of AA and DVB are 1.4 g and 0.1 g,respectively.At last,the process of demulsification is showed under a microscope;the coalescence process of water droplets is indicated under the action of the demulsifier.

Demulsification with simultaneous water purification by coupling filtration and enhanced oil droplet coalescence at anode interface in an electrochemical reactor

With the increasing demand of recycling disposal of industrial wastewater,oil-in-water(O/W)emulsion has been paid much attention in recent years owing to its high oil con-tent.However,due to the presence of surfactant and salt,the emulsion was usually stable with complex physicochemical interfacial properties leading to increased processing diffi-culty.Herein,a novel flow-through electrode-based demulsification reactor(FEDR)was well designed for the treatment of saline O/W emulsion.In contrast to 53.7%for electrical demul-sification only and 80.3%for filtration only,the COD removal efficiency increased to 92.8%under FEDR system.Moreover,the pore size of electrode and the applied voltage were two key factors that governed the FEDR demulsification performance.By observing the mor-phology of oil droplets deposited layer after different operation conditions and the behavior of oil droplets at the electrode surface under different voltage conditions,the mechanism was proposed that the oil droplets first accumulated on the surface of flow-through elec-trode by sieving effect,subsequently the gathered oil droplets could further coalesce with the promoting effect of the anode,leading to a high-performing demulsification.This study offers an attractive option of using flow-through electrode to accomplish the oil recovery with simultaneous water purification.

N-Doped Carbon Nanofibrous Film with Unique Wettability,Enhanced Supercapacitive Property,and Facile Capacity to Demulsify Surfactant Free Oil-in-water Emulsions

Electrospinning and calcination technique have been combined to fabricate N-doped carbon nanofibers(N-CNFs)by introducing amino grafted few-layered hexagonal boron nitride(amino@BN)into polyacrylonitrile(PAN)matrix as filler followed by carbonization.For the high N-doping level(10.7%,atomic fraction)with the final product,the as-prepared N-CNFs exhibit interesting surface wettability(superamphiphilicity in air and underwater oleophilicity).Moreover,compared with pristine PAN derived carbon nanofibers(marked as CNFs),N-CNFs exhibit higher graphic structure under fixed carbonizing temperature as well.Taking these advantages aforementioned,the as-prepared N-CNFs exhibit good specific capacitance(ca.200.1 F/g)without activation treatment at the current density of 0.5 A/g in three-electrode configuration,which is about 149%that of CNFs(ca.134 F/g).What’s more,our N-CNFs also display the unexpected capacity to demulsify diverse surfactant free oil-in-water emulsions by simple filtration in large scale with the high water flux ca.(23578±150)L·m^(−2)·h^(−1).

Selective separation of oil-in-water emulsion with high efficiency by bio-inspired Janus membrane

The efficient and rapid separation of oil from stabilized oil-in-water emulsions with micro/nanometer size is a global challenge.Owing to the low oil content in oil-in-water emulsions,separating the oil by simply controlling the surface wettability is difficult.Controlling the pore size of the membrane surface to achieve separation will lead to a sharp decrease in flux.Herein,inspired by cell membrane transportation,a hydrophilic/hydrophobic bifunctional Janus membrane for stable oil-in-water separation was prepared by simple surface polymerization and vapor diffusion.The prepared Janus membrane contained a hydrophobic side and hydrophilic polyamine layer.When used for oil-in-water emulsion separation,the polyamine layer accumulated micro/nanometer oil droplets,forming an oil layer on the hydrophobic surface.Water was retained by the 1H,1H,2H,2H-perfluorooctyl trichlorosilane layer,allowing oil droplets to selectively permeate through the membrane,achieving the separation effect.As the pore size of the modified fabric was basically unchanged,the permeation flux was fast(1.53×10^(3) Lm^(−2) h^(−1)).Furthermore,the poly(N,N-dimethylaminoethyl methacrylate)layer destroyed the emulsion stability,making the emulsion droplets aggregate without affecting the separation efficiency with fast permeation flux.Therefore,the prepared bifunctional Janus membrane shows great potential for actual wastewater treatment.

Clinical efficacy of albendazole emulsion in treatment of 212 cases of liver cystic hydatidosis

OBJECTIVE: To evaluate the clinical efficacy of a new formulation of albendazole emulsion (AbzE) in cases of liver cystic hydatidosis. METHODS: Two regimens of AbzE (10 mg.kg(-1).d(-1) and 12.5 mg.kg(-1).d(-1)) were given to 212 patients with liver cystic hydatidosis in courses ranging from 3 months to more than one year. Assessment of drug efficacy was essentially based on imaging signs with ultrasonography as the main tool. Assessments were performed at the end of different courses and in the follow-up study of 1 - 4 years after the cessation of therapy. RESULTS: At the end of therapeutic courses, the overall cure rate of the 212 cases was 74.5%, with a 99.1% effective rate. In the follow-up study, the cure rate was 83.1%, effective rate was 89.3%, ineffective rate was 0.6%, and recurrence rate was 10.2%. The highest cure rate was observed in cases receiving AbzE 12.5 mg.kg(-1).d(-1) for 9 months. Retreatment of recurrent cases with AbzE obtained satisfactory results. CONCLUSIONS: AbzE surpassed other currently used antihydatidosis drugs or formulations with its promising efficacy and mild side effects, and could be recommended as a drug of choice in the treatment of cystic hydatidosis.

Aggregation-induced demulsification triggered by the hydrophilic fabric for the separation of highly emulsified oil droplets from water

A functional fabric with hierarchical structure consisting of basalt fibre fabric as a substrate and polyvinyl alcohol as a coating was developed,aiming at providing a low cost and high-performance way to separate highly emulsified oil in water.The coating functioned as a hydrophilic gate for the penetration of water in the emulsion,whereas the micro-channels formed in the fabric offered capillary force for the continuous flow of water.The synergy of these two materials led to the increase on the oil concentration in the liquid,which in turn enhanced the collision of emulsified oil droplets to aggregate into large ones in the emulsion and resulted separation from the water.Based on these findings,an aggregation-induced demulsification process was proposed to explain the above phenomenon,and the mechanism was confirmed by studying the distribution of oil droplets in emulsion with a controlled separation degree.

微波—离子液体协同破乳的参数优化研究

针对稠油O/W型乳状液难以破乳的问题,本文采用响应面方法对微波辐射功率、微波辐射时间和离子液体浓度等参数进行优化,在此基础上,进一步确定搅拌速率、搅拌时间、破乳温度的最佳参数。实验结果表明,微波和离子液体协同作用可以显著提高稠油乳状液的破乳效果,当微波辐射功率为400 W、微波辐射时间为40 s、离子液体[C_(16)MIM]Br浓度为1.337 mmol/L、搅拌速率为1200 r/min、搅拌时间为5 min、破乳温度为75℃时,稠油O/W型乳状液破乳效率达到最高值99.10%。该研究为微波-离子液体破乳技术在现场的应用提供了理论支撑。

前沿科研成果融入药物化学实验教学——香茅精油微乳液的制备和理化性能研究

本论文利用水蒸气蒸馏法提取香茅精油,用气质联用测定其各组分含量。采用相图研究探索表面活性剂、助表面活性剂、水硬度等微乳液影响因素的影响规律,确定微乳剂配比,按照国家标准方法测定微乳液的稳定性,用透射电镜观测其样貌和粒径。在微乳液的制备过程中可以培养学生的理论与实践相结合的能力,提高学生的科学素养,达到纳米材料的初步认知和了解,引领学生对化学应用到药学的交叉学科的兴趣,为药物化学实验教学改革提供了参考。

以废弃PET塑料为原料制备离子液体破乳剂

传统以环氧乙烷和环氧丙烷为原料的聚醚类破乳剂需要危险复杂的生产过程,而且破乳性能仍然难以满足实际生产的要求。利用废弃聚对苯二甲酸乙二醇酯(PET)塑料为主要原料,合成了一种用于油包水(W/O)原油乳液脱水的离子液体破乳剂BADT-IL,采用傅里叶变换红外光谱仪(FT-IR)和核磁共振氢谱仪(^(1)H-NMR)分析了BADT-IL的化学结构,考察了BADT-IL浓度、沉降时间、破乳温度、盐度和pH值对原油乳液破乳效率的影响,并通过测试界面张力(IFT)、Zeta电位、三相接触角(CA)、聚结时间和显微观察等多种手段对BADT-IL在原油乳液中的破乳机理进行了探讨。研究结果表明,在含水率为70%的原油乳液中加入250 mg/L的BADT-IL,60℃条件下静置180 min后破乳效率高达95.23%;同样的条件下,对含水率为30%的原油乳液的破乳效率达到99.22%,且分离后水相清澈、油水界面整齐。BADT-IL具有良好的耐盐性,而且增大盐度能提升破乳效率,在50 g/L的条件下,含水率为70%的原油乳液的破乳效率为96.33%。随着破乳温度的升高,破乳速率显著加快,且破乳效率也随之提高。此外,与常用的商业破乳剂对比,BADT-IL表现出优异的破乳性能。BADT-IL在破乳过程中能够有效降低油水界面的IFT,并取代界面处的乳化剂,形成不稳定的复合界面膜从而促进水滴的聚结,最终实现有效的油水分离。

超亲氮化碳-硅藻土复合滤层油包水乳液快速破乳

目的实现高黏度油品油包水乳液的快速高效破乳。方法以三聚氰胺为原料,通过热聚法制备超亲水材料氮化碳,采用制备的氮化碳混合硅藻土制备复合滤饼,通过抽滤实现高黏度油包水乳液快速破乳。结果含质量分数为1.5%氮化碳的0.5 cm氮化碳-硅藻土滤饼可实现水含量在6%(w)以内,乳滴粒径在2.32μm及以上,油包水乳液完全破乳,20 kPa真空度的破乳速率可达3.57 L/min,破乳效率为97.36%,油回收率为99.72%以上;增大破乳用滤饼厚度,可用于更高含水量乳液的破乳;破乳基于超亲氮化碳对水的强吸引力和硅藻土微孔破碎共同作用。结论氮化碳-硅藻土滤饼可实现油包水乳液快速高效破乳,具工业实用前景。

氧化石墨烯辅助的超分子骨架膜用于水包油型纳米乳液的高效分离

制备可以同时高效且高通量地处理纳米乳液的超浸润材料仍然具有挑战。为此,本文提出了一种通过在超分子骨架纳米片上修饰氧化石墨烯以增强亲水性的策略。通过将两种具有片状形态的材料连续抽滤于商业基质上,可制备得到氧化石墨烯辅助的超分子骨架复合膜,并用于分离具有纳米尺寸液滴的水包油乳液。骨架一方面通过均匀的纳米孔拦截乳液中分散的微小液滴,另一方面也通过带负电的表面提供静电相互作用来驱动破乳过程发生。具有良好亲水性的氧化石墨烯赋予膜材料改善的亲水能力和水合层。该复合膜具有纳米级的截留尺寸、带负电的表面和水下疏油性,并且还获得了高的水通量和耐油污染性。基于尺寸筛分和破乳效应,该复合膜可有效地去除分散在水包油乳液中由非离子、阴离子和阳离子表面活性剂稳定的纳米油滴。特别是对于离子型乳液,在分离后动态光散射未检测出残留液滴。滤液中总有机碳含量小于10 ppm,对应着大于99.9%的分离效率,优于许多国家和组织的标准。在各种乳液的分离过程中,复合膜表现出较高的分离渗透性,约为原始骨架膜的3.5倍。此外,具有防污效果的复合膜获得了较高的通量回收率,通过简单的水洗处理即可实现5次具有稳定分离性能的循环。该复合膜在重复使用过程中没有组分损失,在150℃内具有热稳定性,并能抵抗腐蚀性化学环境。在本工作中,我们试图将具有不同结构特性和表面特性的两种组分结合,通过简单的方法制备复合膜,并在功能协同作用下实现水包油型纳米乳液的高性能分离。

响应型Pickering乳液研究进展(Ⅰ)

从制备乳液常见的固体乳化剂出发,分析了Pickering乳液稳定性的影响因素,总结了pH值响应、CO_(2)响应、光响应、磁响应、温度响应和多重响应型Pickering乳液的响应机理,并讨论了目前存在的问题。根据Pickering乳液的响应原理设计合成高性能、低成本的两亲性响应纳米颗粒,制备环保、可持续性发展的Pickering乳液将是下一步的发展方向。