Liquid Surfactant Membrane Process Research Articles

Elimination of rare earth (neodymium (III)) from water by emulsion liquid membrane process using D2EHPA as a carrier in kerosene

The present paper highlights the process for the purification of water, which contains Neodymium (III).The applicability of the Liquid Surfactant Membrane (LSM) process for the removal and the concentration of Nd (III) was investigated. The LSM consists of di-(2-ethylhexyl) phosphoric acid as a carrier, commercial kerosene as an organic solvent, span 80 as an emulsifying agent, and sulphuric acid as a stripping phase. The important factors studied which affect the removal Nd (III) are the concentrations of surfactant (1–9% w/w), carrier (0.05–0.9% w/w), internal phase (0.05–1 N H2SO4), pH of feed solution, stirring speed (100 −400 rpm), external phase concentration and type of diluent. The results showed that it is possible to remove 95% of Nd (III) after 15 min contact time by using ELM at the optimum operating conditions. The application of this new membrane matrix based on sulphuric acid used as inner phase, sorbitan monooleate as a surfactant, and D2EHPA as an extractant in kerosene as a diluent has been proven effective for extracting Neodymium (III) ions in water.

Red 3BS dye extraction in liquid surfactant membrane using continuous extractive reactor process

Nowadays, the use of liquid membrane process in treating dye waste solution is more preferable compared to the batch mode as it provides higher recovery performance and huge treated volume. The aim of this paper is to determine the extraction efficiency of using continuous liquid surfactant membrane (CLSM) process for extraction of reactive dye Red 3BS in order to ensure that LSM process more applicable and commercialize in industries. Liquid membrane process comprises of three liquid phases which are external (dye aqueous solution), organic liquid membrane and internal aqueous phase was developed. Liquid membrane and internal aqueous phase were emulsified and dispersed into the wastewater solution (feed/dye aqueous phase) to be treated. The organic liquid membranes contain Aliquat 336, D2EHPA, Sorbitan Monooleote (Span 80) and kerosene as an extractant, synergist extractant surfactant and diluents, were used respectively. The sodium hydroxide (NaOH) was used as stripping agent in internal aqueous phase for the recovery process. The main factors studied for continuous dye extraction process were agitation speed, retention lime and treatment ratio. The system shows stable performance within 15 min duration of continuous extraction time along the process. The results showed that almost 100 % of Reactive Red 3BS ions were successfully extracted at the optimum conditions of 250 rpm agitation speed, 1: 7 of treatment ratio and 5 min of retention time. Therefore, as a conclusion, CLSM can be proposed as a very promising method for extraction of Red 3BS.

Removal of-Copper Ions-from Aqueous Solution Using Liquid-Surfactant-Membrane Technique

Extraction of copper (Cu) from aqueous solution utilizing Liquid Membrane technology (LM) is more effective than precipitation method that forms sludge and must be disposed of in landfills. In this work, we have formulated a liquid surfactant membrane (LSM) that uses kerosene oil as the main diluent of LSM to remove copper ions from the aqueous waste solution through di- (2-ethylhexyl) phosphoric acid - D2EHPA- as a carrier. This technique displays several advantages including one-stage extraction and stripping process, simple operation, low energy requirement, and. In this study, the LSM process was used to transport Cu (II) ions from the feed phase to the stripping phase, which was prepared, using H2SO4. For LSM process, various parameters have been studied such as carrier concentration; treat ratio (TR), agitating speed and initial feed concentration. After finding the optimum parameters, it was possible to extract Cu up to 95% from the aqueous feed phase in a single stage extraction.

Surface modification of PVDF ultrafiltration membranes by remote argon/methane gas mixture plasma for fouling reduction

Ultrafiltration (UF) is considered as a potential alternative to gravity settling in liquid surfactant membrane process for fast separation of water-in-oil (W/O) emulsions from the external aqueous phase. Flux behavior was studied in this work during batch UF of W/O/W solutions by poly(vinylidene fluoride) (PVDF) membrane with a molecular weight cut-off of 30kDa after the membrane was modified by remote cyclonic atmospheric-pressure plasma with argon gas and methane/argon gas mixture. Physicochemical properties of the membrane surfaces including hydrophilicity, functional group concentrations, and pore size distribution before and after plasma modifications were determined by static contact angle measurements, X-ray photoelectron spectroscopy, and capillary flow porometry, respectively. Higher surface concentrations of oxygen functional groups for plasma-functionalized membranes were observed compared to the unmodified membranes. It was shown that UF flux was significantly enhanced with the plasma-modified membranes under the conditions studied (feed, 5vol% W/O emulsions; stirring, 300rpm; pressure, 35–138kPa). Resistance-in-series analysis of the flux data indicated that the proposed remote plasma treatment, particularly with methane/argon gas mixture, could considerably reduce both resistances due to solute adsorption and cake layer formation on the membrane surface, although the above two resistances always contributed more than 71% of the total filtration resistance.

Uranium(VI) extraction by liquid surfactant membrane with N-alkylcaprolactams as a carrier

A liquid surfactant membrane process for separating U(VI) from sulfuric acid media was investigated using N-alkylcaprolactam (B s) as a carrier. The operating conditions, including the concentrations of the extractant and stripping agent and the volume ratios of the (W/O)/W emulsion were optimized for the U(VI) extraction, from the viewpoint of their effect on the kinetics and recovery efficiency as well as the stability of the (W/O) emulsion drops. It was found that the liquid membrane containing n-dodecane used as a solvent, ECA4360J as a surfactant and B 8 as a carrier is an effective membrane for extracting U(VI) from sulfuric acid, and the concentrations of B 8 should be within the range between 0.03 and 0.05 M for keeping the emulsion stability. At the same time, a two-stage counter-current operation was demonstrated and results showed that LSM process in two-stage operation is effective.

Ultrasound-assisted production of W/O emulsions in liquid surfactant membrane processes

Liquid surfactant membrane (LSM) process is a novel and effective method for the recovery and separation of heavy metals and amino acids from aqueous solutions. Repeated production and destruction of W/O emulsions plays a crucial role in the LSM process. The aim of this work was to study the efficiency of emulsification with horn ultrasound (20 kHz), in which the organic phase contained the surfactant Span 80 and the acidic carrier di(2-ethylhexyl)phosphoric acid (D2EHPA) in kerosene. The (internal) aqueous phase consisted of divalent Cu(II)-EDTA chelated anions as the tracers. All experiments were performed as a function of emulsification time, surfactant and carrier concentrations, ultrasonic power, and volume ratio of the internal aqueous phase to organic phase. It was shown that in most cases the emulsification was finished with 1 min. With ultrasound, the droplet sizes of W/O emulsions (Sauter diameter, d 32) were much smaller than those reported previously by mechanical agitation. The effect of ultrasonic power and surfactant concentration on the droplet size was also investigated. Finally, the possibility of ultrasound demulsification was evaluated and discussed.

Amino acid separation with D2EHPA by solvent extraction and liquid surfactant membranes

Separation of binary amino acids from aqueous solutions by solvent extraction (SX) and liquid surfactant membrane (LSM) was compared, in which the acidic extractant di(2-ethylhexyl)phosphoric acid (D2EHPA) was selected as an active carrier. The distribution ratios were measured by batch SX experiments. Important variables affecting LSM permeation experiments, including the pH in the aqueous external phase, surfactant concentration, the volume ratios of W/O emulsions to aqueous external phase and that of organic to aqueous internal phases, and HCl concentration in the internal phase, were systematically studied. It was shown that the separation was promising only when the amino acids had sufficiently different isoelectric points. Compared to batch SX results, the optimal pH for effective separation shifted to a lower level and the selectivity was enhanced in LSM process, which was a result of the counter transport of hydrogen ions.

A Practicable Process for Phenol Removal with Liquid Surfactant Membrane Permeation Column

A practicable liquid surfactant membrane process for phenol removal is proposed with a stirred countercurrent column used as the liquid membrane contact equipment. The constituents of liquid membranes, such as internal aqueous phase and surfactant, the type of column, and the operating conditions for efficient and continuous performance of the liquid surfactant membrane process, have been examined. When NaOH solution was used as the internal aqueous phase and ECA4360J was used as the surfactant, the W/O emulsion was stable for the duration of column operation. More than 97% phenol could be removed from the feed solution. Nearly complete demulsification was also achieved by gentle agitation with an electrostatic demulsifier.

Selective recovery of palladium from a simulated industrial waste water by liquid surfactant membrane process

The selective recovery of palladium from an acidic solution of high iron concentration with liquid surfactant membranes (LSMs) containing di-2-ethylhexyl monothiophosphoric acid (commercial name MSP-8) as a carrier has been conducted in a batch and a continuous system using a mixer-settler. In the batch operation, the effects of several chemical species and their concentrations on the recovery of palladium were discussed. Using a relatively low concentration of PX100, stable emulsions were obtained and a high degree of palladium recovery was performed by a LSM technique. The concentration of thiourea employed as a stripping agent greatly affected the efficiency of palladium recovery. Under optimum conditions, palladium ions were separated from a large amount of iron ions and they were concentrated from the external feed aqueous solution into the inner receiving phase of W/O emulsions. Furthermore, an effective recovery of palladium could be achieved in a continuous operation using a mixer-settler under the optimum conditions for the batch system.

Analytical and numerical solutions of fixed and moving boundary problems for liquid surfactant membrane processes

A mathematical model describing a batch liquid-surfactant-membrane (LSM) process is developed. In addition to unsteady-state diffusion, reaction, and external mass transfer, consumption of the reagent by the reaction is also considered. Thus, depending on the Thiele modulus and the initial amount of the reagent, the model either remains to be a fixed boundary problem throughout the whole process or changes to a moving boundary problem after some initial period of fixed boundary. For the fixed boundary problem a general analytic solution is obtained in an eigenfunction expansion by a self-adjoint formalism in linear operator theory. In contrast tot he known perturbation solution, the solution is exact and straightforward to use. For typical operations the series solution converges rapidly within a few terms, providing a useful tool in design and analysis of the LSM process. Also the solution readily enables determination of the time of transition from fixed to moving boundary. For the moving boundary model, a simple numerical method based on a fixed-grid finite difference method is constructed for solution. In this method the position of the moving boundary is approximated to a grid point at which depletion of the reagent occurred most recently. The calculated position of the moving boundary has been found to be accurate to the size of the grid. The method has also been found to be stable and reliable for all practical ranges of its application.

Dearomatisation of a refinery kerosene by liquid surfactant membranes - prediction of extraction rates

A possible low energy alternative to solvent extraction processes for kerosene dearomatisation to meet product specifications of low aromatic content in jet fuels/superior kerosene, is the liquid surfactant membrane (LSM) process as demonstrated in several recent papers. However, for design of separation equipment by this process, predictive mass transfer models are required. The present study shows that the analytical solution to the transient diffusion equation as developed by Vorstmann and Thijssen for liquid-liquid extraction can be used to predict the extraction rate of kerosene aromatics through LSM. The parameters required in the model calculations can be measured experimentally or can be estimated independently. The calculations are based on the assumption that the kerosene aromatics can be represented by a model hydrocarbon, 1-methylnaphthalene. The model should prove a useful tool in design/simulation calculations for a kerosene LSM refining process.

Membrane recycling in the liquid surfactant membrane process

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMembrane recycling in the liquid surfactant membrane processI. Abou-Nemeh and A. P. Van PeteghemCite this: Ind. Eng. Chem. Res. 1993, 32, 7, 1431–1437Publication Date (Print):July 1, 1993Publication History Published online1 May 2002Published inissue 1 July 1993https://doi.org/10.1021/ie00019a017RIGHTS & PERMISSIONSArticle Views151Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (926 KB) Get e-Alerts Get e-Alerts

Extraction of multi-component system of metals from simulated and industrial effluents by liquid surfactant membranes (LSM)

A study of metal extraction from a multi-component system was carried out by applying a liquid surfactant membrane (LSM) process. The system was an industrial effluent which contains a mixture of metallic species such as Na(I), Mn(II), Co(II), Ni(II), Fe(III) and Cr(III). Concurrently, an analogous research programme was conducted on model solutions reproducing nearly the same physical and chemical composition as the industrial feed. The main goal behind this endeavour was to elucidate the effect of impurities and other components co-existing alongside the metallic species in the industrial feed. Di-2-ethylhexyl phosphoric acid (D2EHPA) was used as a carrier with tri-n-butyl phosphate (TBP). The latter's influence on the kinetics of metal extraction occupied a major part of the investigations. It was found that an optimal composition of the extracting mixture exists (5.5 vol.% D2EHPA + 0.5 vol.% TBP) at which a maximum extraction efficiency can be achieved. It has also been revealed that, although the selectivity is relatively poor, it can be improved by varying the concentration of TBP in the membrane phase. The raffinate kinetic profiles of the simulated solutions have been shown to fit those of the industrial effluent adequately.

Sorbitan monooleate (Span 80) decomposition during membrane ageing. A kinetic study

A study has been carried out to investigate the kinetics of surfactant decomposition during ageing of the membrane (organic phase) of the emulsion used in an liquid surfactant membrane (LSM) process for metals separation. At this stage of research, the process of Span 80 hydrolysis has been exclusively studied in the membrane phase, and thus, the effect of the carrier di-2-ethylhexyl phosphoric acid (D2EHPA) on the rate of hydrolysis. The effect of tri-n-butyl phosphate (TBP) and the membrane composition on the kinetics of Span 80 hydrolysis have been studied as well. It has been found that the bimolecular irreversible second-order kinetic model describes fairly well the experimental data. A numerical best-fit routine of a polynomial form has been exploited to modify the final model, which takes into account the TBP effect on the result rate of the proposed model.

Development of a Continuous Electric Coalescer of W/O Emulsions in Liquid Surfactant Membrane Process

Abstract The development of an efficient, continuous demulsification apparatus is needed in the industrial separation process utilizing the liquid surfactant membrane technique. A test apparatus for continuous demulsification was constructed in which a pulsed dc high potential is applied to W/O emulsions flowing between parallel copper electrodes of a perforated plate. Efficient demulsification was achieved by an operation in which the demulsified oil phase was absent between the emulsion and the upper electrode. When the feed rate of emulsion was adjusted to be equal to the demulsification rate, the latter value was proportional to the square root of the applied potential and independent of the distance between the electrodes.

Study of Operating Condition Affecting Mass Transfer Rate in Liquid Surfactant Membrane Process

Abstract The removal of acetic acid from its dilute solution by liquid surfactant membrane (LSM) has been investigated by batch test. Some important factors affecting the mass transfer rate, such as surfactant and its content, stirring speed, ratio of reagents, treating ratio and volume ratio of membrane phase to internal phase, have been studied. The breakage and the swelling of the emulsion have also been investigated. The transport mechanism of HAc across the membrane in the system is referred to as I-II facilitated transport mechanism.

Development of new surfactant for liquid surfactant membrane process.

To obtain more stable W/O emulsion for liquid surfactant membrane technique, a series of glutamic acid dialkyl esters and dialkyl type quaternary ammonium salts as new surfactants in place of Span 80 and polyamine were synthesized. The adsorption equilibria between aqueous solution and organic solution containing the synthesized surfactants were elucidated and the stability of liquid surfactant membrane made of these surfactants was examined in a stirred tank. A series of synthesized surfactants having two long alkyl chains in hydrophobic site gave more stable emulsion at a lower concentration compared with Span 80 and polyamine. Among them, glutamic acid dioleyl ester formed the most stable emulsion.

The liquid surfactant membrane process: Effect of the emulsifier type on copper extraction by LIX65N-LIX63 mixtures

In order to investigate the role of the emulsifier type in the liquid surfactant membrane (LSM) extraction process, a comparative study of the performance of four different emulsifiers, Span 80 (active ingredient: sorbitan monooleate), Arlacel 83 (active ingredients: sorbitan mono- and dioleates), Span 85 (active ingredient: sorbitan trioleate), and Brij 72 (active ingredient: polyoxyethylene(2)stearyl ether) in LSM copper extraction systems has been undertaken. The experimental techniques employed included interfacial tension, membrane-phase viscosity, emulsion viscosity, membrane stability (as determined by K + transfer from the internal to the external phase) and LSM copper transfer measurements. Interfacial tension measurements conducted both in the presence and in the absence of the extractant (LIX65N) indicated that the interfacial activity of the emulsifiers increased in the order Brij 72 < Span 85 ⪡ Arlacel 83 ⋍ Span 80 . The emulsifier concentration required to achieve good stability varied widely with the emulsifier type (e.g., 0.1 kmol m −3 Span 80, 0.32 kmol m −3 Span 85, and 0.37 kmol m −3 Brij 72 at 5% membrane breakdown) and correlated with the relative interfacial activities. With the exception of Brij 72 LSMs which gave negligible copper transfer, metal extraction at first increased, passed through a maximum, and then decreased as the emulsifier concentration was increased. The initial increase was attributed to a decrease in membrane breakdown. On the other hand, the subsequent decrease in copper extraction with increase in emulsifier concentrations was attributed to a number of possible factors including a decrease in the rate of copper complexation at the membrane phase/external phase interface, an increase in the interfacial viscosity, a decrease in the movement of the internal phase droplets within emulsion globules, and a decrease in the external interfacial area available for metal extraction. The emulsifier concentration giving the extraction maximum increased in the order: Span 80 ( 23.2 g L −1, 0.054 kmol m −3) ⋍ Arlacel 83 (23.2 g L −1) ⪡ Span 85 (155 g L −1 , 0.162 kmol m −3). The corresponding copper extraction (at 2 h) increased in the order: Span 85 (28%) ⪡ Arlacel 83 (78%) < Span 80 (89%). Interfacial tension studies indicated that the very poor extraction performance of Brij 72 LSMs was a result of the complete displacement of LIX65N from the membrane phase/external phase interface/external phase interface. In addition, viscosity measurements indicated that the low copper extraction by Span 85 LSMs might be a result of a relatively low membrane phase/external phase interfacial area or relatively low values for the diffusivities of the carrier and the metal-carrier complex within the bulk membrane phase.

Effect of the Size of Water Droplets in W/O Emulsion on the Extraction of Copper by a Liquid Surfactant Membrane Process

Effect of the Size of Water Droplets in W/O Emulsion on the Extraction of Copper by a Liquid Surfactant Membrane Process

Copper extraction by means of a liquid surfactant membrane process

The liquid membrane technique is a simultaneous extraction-stripping process which can be successfully used for copper recovery. Up to 98% copper can be removed within 30 min from acid feed solutions at a feed solution/liquid membrane ratio of 13:1 and a membrane/stripping phase ratio of 1:1. Using an ion-pumping liquid membrane, copper could be enriched within liquid membrane capsules up to a ratio of 500:1. A model is presented which adequately describes the kinetics of copper removal by liquid surfactant membranes. Mass transfer parameters ( k L a) were determined by means of this model and found to range from 1 X 10 −4 to 1 x 10 −3 sec −1.