Stripping Phase Concentration Research Articles

Modeling of liquid-liquid hollow fiber supported membrane equilibrium including the non-ideality of the aqueous and organic phases in the recovery systems of radionuclides in sulphate-halide/aliquat-336 in O-xylene

Study of modeling of L/LHFSLM equilibrium based on the Non-ideality of the Aqueous and Organic Phases in the Recovery of 152+154Eu in H2SO4-Halides/Aliquat-336 in 20% kerosene as feeding phase at pH 3.78–4.55, by the ratio 89.7%,while separation of 90Sr and 134Cs there was a problem between them by using hollow HFSLM only, the reason for that the organic solvents affect the rate of reaction in the Diamino-1,2-cyclohexane/tetraacetic acid (DCTA) as stripping phase concentration from 0.15 to 0.55 mol/L. The system has been developed; this led to the extraction of elements in the same time. The Matlab software program was introduced to obtain some mathematical parameters like, standard deviation (SD), equilibrium constant Kex and standard deviation coefficient (SDC).

Removal of diclofenac using Fe2O3 nanoparticles stabilised emulsion nanofluid membrane

The present investigation focuses on the removal of Diclofenac (DCF) from aqueous solution by Fe2O3 nanoparticles stabilised emulsion nanofluid membrane (ENM) using n-heptane as solvent and Di-2-ethylhexyl phosphoric acid (D2EHPA) as carrier. Parameters like stripping phase (HNO3) concentration, homogenizer speed and hydrophilic-lipophilic balance were varied to achieve the maximum extraction of DCF. ENMs were characterized by photomicrograph and Turbiscan. Emulsion instability is the main hurdle for the application of emulsion liquid membrane technique on an industrial scale. The study also tries to address this issue. The study is novel in a way as the blending of Span 80 and Span 20 surfactants with Fe2O3 nanoparticles provided stability to emulsion and improved the DCF extraction to 97%. Nanoparticles are interfacially active which ensures better stability to the emulsion and improves the extraction efficiency.

Design and manufacture of emulsion liquid membrane based on various amine extractants for separation and extraction of succinic acid from fermentation broth

The aim of this study was to design a new emulsion liquid membrane (ELM) system for the separation of succinic acid from aqueous solutions. The concentration of succinic acid varied from 20 to 60 mmol·L−1. The prepared ELM system includes tributylamine (TBA) as a carrier, commercial kerosene as a solvent, Span 80 as a surfactant, and Na2CO3 as a stripping agent. In order to control the membrane swelling, different values of cyclohexanone were added to the membrane phase. The effect of various empirical variables on the extraction of the succinic acid such as acid concentration in the feed solution, initial feed concentration, carrier concentration, the stirring speed of the extraction, Na2CO3, surfactant, and cyclohexanone concentrations, and treat ratio in the ELM system. The best result was obtained when TBA was used as the carrier. The final acid extraction efficiency was independent of pH variations of the aqueous feed solution. The extraction of succinic acid solution with a concentration of 40 mmol·L−1 was improved by increasing the treat ratio 1:7–1:3, stripping phase concentration 0.5–1.5 mol·L−1, stirring speed 300–500 r·min−1 and cyclohexanone concentration in the membrane phase 1.2–1.6 mol·L−1. No considerable effect on the extraction rate was observed for the carrier concentration in the membrane phase. But, the surfactant concentration in the feed phase showed a dual effect on the extraction efficiency.

Lactoperoxidase partitioning from whey using the reverse micelles of non‐ionic/ionic mixed surfactants: Improvement of back extraction

The reverse micellar system formed with a mixture of ionic and non-ionic surfactants, AOT (Sodium bis(2-ethyl hexyl) sulfosuccinate)/ Tween 80 in isooctane, was studied for the selective extraction of Bovine Lactoperoxidase (LP) from acid whey. The effect of pH and ionic strength of acid whey and surfactant concentrations were studied and a maximum of 86% LP was extracted from acid whey at pH 9.5 with the addition of 0.2M KCl to the reverse micelles formed with AOT (115 mM) / Tween 80 (23 mM). The back extraction of LP was studied at different aqueous stripping phase pH, ionic strength and concentration of counter-ionic surfactant CTAB (Cetyltrimethylammonium bromide). The back extraction of 112% with 80% LP recovery was achieved when the stripping phase pH was 10.5 with 1.5 M KCl and 60 mM CTAB. The antimicrobial activity of the extracted LP showed reduction in colony forming units of S. aureus.

Artificial neural network approach towards the separation of ethylparaben and diclofenac using pseudo-emulsion hollow fiber strip dispersion technique

Pseudo-emulsion hollow fiber strip dispersion technique is known to be an effective way to separate pollutants from industrial wastewater. In the present study, data driven model like artificial neural network was developed for the prediction of extraction of ethylparaben and diclofenac using pseudo-emulsion hollow fiber strip dispersion technique. The feed, carrier and stripping phase concentration were taken as input parameters, whereas percentage of the extraction was chosen as an output parameter. The models were developed by carrying out the statistical analysis of parameters namely; root mean square error and mean absolute percentage error. The regression values achieved for training data set were 0.9956 and 0.97562 for ethylparaben and diclofenac separation, respectively. The results demonstrated that the artificial neural network model gives an accurate prediction of extraction data and hence can be quite helpful in designing the wastewater treatment plants.

Removal of Dye from Synthetic Wastewater by Liquid Membrane

New technologies have risen into popularity causing the Liquid membrane techniques to evolve over other separation techniques due to its high selectivity and recovery, increased fluxes, and reduced investment and operating cost. This work focuses on extracting Methylene Blue (MB), a cationic dye using a simple BLM separation technique from its aqueous phase. It combines extraction and stripping in a single unit operation. The feed phase was an aqueous solution of MB, the solvent chosen was soybean oil for the liquid/organic membrane phase, and tri-octyl amine acted as a carrier. The strip phase was a hydrochloric acid solution for this study. A two-phase equilibrium study was done to choose the correct solvent, carrier, and receiving phase (soybean oil, tri-octyl amine, and HCl) were chosen, which was then followed by a three-phase study. Effect of various parameters like equilibrium time, feed and stripping phase pH, stirring speed, carrier concentration, initial feed concentration, and strip phase concentration were all studied to find out the most optimum working condition for maximum extraction and recovery of MB. The removal efficiency of MB by using soybean oil was found as 92%, at the optimum process conditions for the transport of MB were found as follows: pH in the feed phase (11), pH in the stripping phase (5), initial concentration of MB (20 ppm), carrier concentration (7%) (v/v) TOA and stirring speed (250 rpm), respectively.

Removal of lead ions using OA-Fe3O4 magnetic nanoparticles-based pickering emulsion liquid membrane: process optimization using box–behnken response surface methodology

ABSTRACT The purpose of this study is to explore the pickering emulsion liquid membrane (PELM) performance for removing divalent lead ions (Pb II) from aqueous solution. In the present work, the membrane phase was prepared by dissolving methyltrioctylammonium chloride (Aliquat 336) with Mahua oil and adding oleic acid coated-ferrosoferric oxide (OA-Fe3O4) as magnetic nanoparticles. Experimental investigation on percentage removal of lead ions was carried out by studying the influencing process parameters such as pH, agitation speed, stripping concentration, initial feed concentration, surfactant concentration, treat ratio, M/S ratio and carrier concentration. The optimum condition to remove 98.52% of lead ions from the feed solutions has achieved at a stripping phase concentration of 0.3 M, treat ratio of 3, agitation speed of 300 rpm, initial feed concentration of 10 ppm and stabilizer concentration of 2 wt%. The experimental results were validated using box–behnken response surface methodology. The extraction ability of OA-Fe3O4 magnetic nanoparticles-based PELM has been evaluated using statistical optimization of all the affecting process factors using the design of the experiments.

Enhanced separation of nitrophenols from wastewater by using ammonium ionic liquid with thiocyanate anion in supported liquid membrane

ABSTRACT The present investigation deals with separation of various types of nitrophenols using SILM technique. Several ionic liquids were developed and the SILM parameters such as role of ILs, feed and strip phase concentration, wastewater pH, salt effect and mixture of pollutants were thoroughly investigated. The percentage extraction and stripping, flux, apparent rate constants and selectivity were evaluated. The selected ammonium IL being more polar than the imidazolium IL showed better separation of 2-nitrophenol. The SILM constituting an ammonium IL with SCN anion exhibited extraction efficiency of >96% and Ka: 0.264 h−1. The change in feed concentration showed maximum transport of nitrophenol at 300 ppm concentration (Ka: 0.673 h−1). The membranes were repeated for 4 cycles which demonstrated good stability for runs of more than 48 hours. The selectivity of 2-nitrophenol, 2,4-dinitrophenol, 2,4,6- trinitrophenol over nitrobenzene was 26, 36 and 58, respectively. The morphology of membranes was studied by using FTIR and FE-SEM and the transport mechanism was elucidated. With the optimized parameters, a concentration factor of 7 can be achieved in the present SILM system. The application of SILM including ammonium IL with SCN anion shows a promising potential for the treatment of various types of nitrophenol bearing wastewater.

The extraction and process optimization of Cu (II) and Cd (II) using Pickering emulsion liquid membrane.

In the present study, the extraction of divalent heavy metals like copper [Cu (II)] and cadmium [Cd (II)] using a Pickering Emulsion Liquid Membrane (PELM) has been investigated by using three different surfactants such as Amphiphilic silica nanowires (ASNWs), Aluminum oxide nanoparticles (Alumina) and Sorbitan monooleate (SPAN 80). The influence of the process parameters such as pH, the stripping phase concentration, the agitation speed, and the carrier concentration on the extraction efficiency have been examined to find the optimum conditions at which the maximum recovery of Cu (II) and Cd (II) could take place. At optimum conditions, the extraction efficiency of 89.77% and 91.19% for Cu (II) and Cd (II) ions were achieved. Non-edible oils were used as diluent in this present study to reduce the need for toxic organic solvents in preparing PELM. The impact of each process factor on the extraction efficiency of Cu (II) and Cd (II) ions has been verified using analysis of variance (ANOVA). The higher values of F and lower values of P (less than 0.05) indicate pH is the most significant parameter on the percentage extraction of Cu (II) and Cd (II) using the Taguchi design approach.

The Feasibility of Emulsion Liquid Membrane for the Extraction of Organic Acids from Wastewater

The separation of hazardous organic acid pollutants such as phenol and carboxylic acids from aqueous waste streams released from industries is important and essential for environmental pollution. Acetic acid, benzoic acid, and phenol individually extracted from their aqueous solutions using emulsion liquid membranes prepared with kerosene as a membrane phase, Span 80 as a surfactant and NaOH as a stripping agent in the inner phase of W/O emulsions. Experiments have been performed to study the effect of volume ratio of membrane phase to internal phase (VM/VI), stripping phase concentration in the internal phase, agitation speed of feed solution, and volume ratio of emulsion phase to feed phase (VE/VF) on the organic acid extraction rates. More than 98% of benzoic acid and phenol can be extracted in less than 5 minutes, acetic can also be extracted but at much slower rates. Comparison of the extraction rates of organic acid indicates that benzoic acid and phenol are extracted more rapidly than that of acetic acid because the distribution coefficient (m) of benzoic acid and phenol is much larger than that of acetic acid due to their ability to dissolve in the membrane phase. The effective diffusivities indicate that the mobility of these compounds in the membrane phase obeys the following order: benzoic acid > acetic acid > phenol.

Recovery and transport of thorium(IV) through polymer inclusion membrane with D2EHPA from nitric acid solutions

Recovery and transport of thorium(IV) from HNO3 medium using a polymer inclusion membrane (PIM) containing di (2-ethylhexyl) phosphoric acid (D2EHPA) as the carrier, and polyvinyl chloride (PVC) as polymer were studied. Taguchi L-16 orthogonal array was used to evaluate the effects of the membrane’s carrier content, pH, strip phase type and concentration, and initial concentration of Th(IV) on the cation transport. Using a 45% (m/m) D2EHPA-55% (m/m) PVC PIM, Th(IV) is completely separated from a number of common metal cations. Studies on the transport kinetics and the stability of the membranes were also performed. The results showed that the PIM has excellent stability.

Removal of Acetaminophen Residues from Wastewater by Bulk Liquid Membrane Process

The removal of Anit-Inflammatory drugs, namely; Acetaminophen (ACTP), from wastewater by bulk liquid membrane (BLM) process using Aliquat 336 (QCl) as a carrier was investigated. The effects of several parameters on the extraction efficiency were studied in this research, such as the initial feed phase concentration (10-50) ppm of ACTP, stripping phase (NaCl) concentration (0.3,0.5,0.7 M), temperature (30-50oC), the volume ratio of feed phase to membrane phase (200-400ml/80ml), agitation speed of the feed phase (75-125 rpm), membrane stirring speed (0, 100, 150 rpm), carrier concentration (1, 5, 9 wt%), the pH of feed (2, 4, 6, 8, 10), and solvent type (CCl4 and n-Heptane). The study shows that high extraction efficiency for ACTP of about 97% was achieved by a bulk liquid membrane at 50 ppm initial concentration of feed; stirring speed of feed phase 130 rpm; stirring speed of membrane phase 100rpm; 0.5 M NaCl concentration; carrier concentration 1wt%; volume ratio of 200ml feed:80ml membrane; feed pH of ACTP is 6, and 50˚C. The transport kinetics was evaluated using a kinetic model with two consecutive first-order irreversible reactions. The kinetics of (ACTP) transport by bulk liquid membrane was investigated at the best experimental conditions. The activation energy values of the extraction and stripping processes were 1.733 and 1.826 kJ.mol−1. The activation energy confirms that the transport process from solutions is controlled by diffusion.

Removal of hexavalent chromium from wastewater using supported liquid membrane: synthesis of chromium‐iron complex through electrochemical reaction

AbstractTreatment of wastewater containing hexavalent chromium is the issue in this research. Supported liquid membrane with in situ electrochemical reaction in stripping section helps to reduce hexavalent chromium to trivalent chromium by forming chromium‐iron complex. Iron plate acts as anode in stripping section. The chromium‐iron complex is an useful value added product that can be used for various purposes such as catalyst in water‐gas shift reaction. Aliquat 336 has been used as carrier for transport of hexavalent chromium. Various physico‐chemical parameters have been optimised to detect the condition of maximum transport and precipitation of chromium‐iron complex in stripping phase. The important physico‐chemical parameters such as strip phase concentration, strip phase pH and concentration of carrier (% v/v) in Liquid Membrane have been selected through response surface methodology to obtain optimum performance for %precipitation of chromium.

Experimental studies on removal of arsenites from industrial effluents using tridodecylamine supported liquid membrane.

In this article, we report the efficient removal of arsenic in the form of arsenite (As(III)) from an aqueous solution which was applied on the industrial effluents. A flat-sheet polypropylene-supported liquid membrane (SLM) was clamped between the feed phase and strip phase in a liquid membrane permeator setup using tridodecylamine (TDDA) as carrier for extraction of As(III). We have optimized the reaction in changing different parameters such as metal, acid concentration in feed phase, strip phase concentration, and carrier concentration for the maximum As(III) transport through the SLM. The flux value, time of extraction, the stoichiometry of the complex formed, and membrane stability were also investigated. As a result of different experiments performed, we find the best conditions of 0.1mol/L of TDDA, 1.0mol/L of HCl in feed phase at optimum pH1, and 1.0mol/L of NaOH in stripping phase for the maximum As(III) removal. The optimized reaction was utilized on effluent collected from different industries. During repeated set of experiments on a single polypropylene membrane, it was found that it could withstand five consecutive experiments. Moreover, as high as 93% of extraction efficiency was achieved in 180min.

Removal of acetic acid from aqueous solutions using bulk ionic liquid membranes: A transport and experimental design study

In this research, the removal of acetic acid from aqueous solutions using bulk ionic liquid membrane (BILM) containing tributyl phosphate (TBP) was investigated. The effects of various parameters in BILM like the stirring, the initial acetic acid concentration in feed phase, the extractant (TBP) concentration and the selectivity of different ionic liquids in the membrane phase and the stripping phase type and concentration were investigated. For this purpose, a statistical experimental design study was applied. Face-centered central composite design (FCCCD) was utilized as the experimental design. The values of extraction and stripping removal efficiencies of different BILM systems were determined, and compared. Also, the optimal conditions to acquire the higher removal efficiency were determined. The higher removal efficiency values were obtained in systems where the TBP concentration in the membrane phase was 2 mol/L and NaOH concentration in the stripping phase was 4 N. The removal study shows that BILM can be used as an effective method for the removal of acetic acid from its aqueous solutions.

Liquid surfactant membrane for lead separation from aqueous solution: Studies on emulsion stability and extraction efficiency

As an alternative extraction technique, Liquid Surfactant Membrane (LSM) reveals several benefits in terms of efficiency, cost effectiveness and easy demulsification post extraction, without altering the chemistry of the oil phase. In this study, the extraction and re-extraction of lead (Pb) from aqueous solution via the liquid surfactant membrane (LSM) technique are investigated. LSM contains Bis-2-ethylhexyl phosphoric acid (D2EHPA) as a carrier, H2SO4 as the internal phase, kerosene as the diluent stabilized by the surfactant (Span 80), all of which have been used to investigate its ability to extract the Pb from aqueous solutions. The effect of the Span 80 concentration, homogenizer speed, extractant concentration, the volume ratio of an organic to an internal phase (O/I), stripping phase (H2SO4) concentration and the emulsified time on the LSM stability and its extraction efficiency were studied. The reused oil phase showed an extraction percentage which was as high as the original oil phase. Besides, from the results it was clear that the removal of more than 98% of the Pb from feed solutions was possible, with the emulsion breakage below 2.8% after 10 min of contact time under the best-operating conditions for the original and reused emulsions.

Extraction of Cr (VI) by pickering emulsion liquid membrane using amphiphilic silica nanowires (ASNWs) as a surfactant

Pickering emulsion is the replacement of surfactants with solid, often nano-sized particles. The particle-stabilized emulsions have good thermodynamic and kinetic stability. Pickering emulsion liquid membrane (PELM) was prepared using mahua oil as a diluent, aliquat 336 (Trioctyl methylammonium chloride) as a carrier and amphiphilic silica nanowires (ASNWs) (10–40 ml ethanol addition) as a surfactant. Sodium hydroxide (NaOH) was used as stripping phase in the concentration range from 0.1 to 0.5 M for the extraction of hexavalent chromium [Cr (VI)] from aqueous solution. The variety of edible and non-edible oils was investigated for the stability of water in oil emulsion. Factors that influence silica-stabilized Pickering emulsions are pH, agitation speed, stripping phase concentration, the volume ratio of membrane to stripping phase (M/S), initial feed concentration, treat ratio(feed to emulsion volume ratio) and surfactant concentration for better PELM stability. And also, the extraction efficiency of Cr (VI) was investigated using aliquat as a carrier. The physicochemical properties of ASNWs were studied using Scanning Electron Microscopy (SEM), Fourier Transforms Infrared Spectroscopy (FTIR) and Dynamic Light Scattering (DLS) techniques. At an optimum condition, 99.69% of Cr (VI) removal from aqueous solution was obtained.

Extraction of Ethylparaben by emulsion liquid membrane: Statistical analysis of operating parameters

Ethylparaben, alkyl esters of p-hydroxybenzoic acid, is an endocrine disruptor that interfere glandular activity and hormone production and even with considerable elimination of them using conventional treatment methods, it is still recognized in river water samples at high concentrations. In this study, Emulsion Liquid Membrane (ELM) consisted of trioctylamine (TOA) as carrier, n-heptane as diluent, Span 80 as surfactant and Na2CO3 as the stripping solution was used for the removal of ethylparaben (EP) from aqueous solution. Studies were conducted to analyse the effect of various operating parameters. Effect of factors like carrier concentration (C), stripping phase concentration (N), speed of homogenizer (H), surfactant concentration (S) on the extraction of EP were evaluated with Taguchi's method. Statistical analysis of variance (ANOVA) was applied to analyze the effect of each parameter and stripping phase concentration (0.5 N Na2CO3) followed by speed of homogenizer (13500 rpm) were found to be the most influencing parameters. Photomicrographs of emulsions and droplet size analyzer were used to study the impact of speed of homogenizer on emulsion droplet size and size distribution. Dispersion destabilization of the emulsion was detected by Turbiscan. Atomic force microscopy and Fourier transform infrared spectroscopy were used to analyse dimensions, shape of emulsion droplet and also to confirm bonding and the presence of different functional groups. Experimental design for multivariable optimization by Taguchi had also been implemented. Using a stable emulsion at optimum condition ∼90% extraction of EP was achieved.

Selective extraction of dysprosium from acidic solutions containing dysprosium and neodymium through emulsion liquid membrane by Cyanex 572 as carrier

The selective extraction of Dysprosium (Dy) from acidic solutions also containing Neodymium (Nd) was studied using an Emulsion liquid membrane (ELM). Cyanex 572 was successfully applied as carrier. The liquid membrane phase consists of kerosene as diluent, Span 80 as surfactant, Cyanex 572 as carrier, and hydrochloric acid solution as stripping phase. Initially, the effects of different parameters such as carrier concentration, stirring speed, feed phase pH, surfactant concentration and their interactions on Dy extraction were investigated and the values of them were optimized by response surface methodology. Based on the results, the role of pH is very important in the ELM process for extraction of Dy by Cyanex 572. Thereafter, the selectivity of the membrane, represented by extraction, enrichment, and separation factor, was analyzed systematically with a view to optimizing the emulsion stability. The effect of important operating parameters governing the extraction and selectivity in ELM process namely feed phase pH; carrier and stripping phase concentration, initial concentration of Dy and Nd, and time of extraction have been investigated. It was found that it is possible to selectively extract 98.99% of Dy from the acidic feed solution containing Dy and Nd though ELM after 10min and maximum enrichment and separation factor can be achieved under the optimum conditions.

Evaluation of Kinetic Parameters at the Transport of Indole-3-acetic Acid Through Bulk Liquid Membranes

Indole-3-acetic acid is a growth phytohormone considered the most important representative of auxin class. This paper presents the assessment of some kinetic parameters in the process of transport of indole-3-acetic acid taking into consideration the kinetic model of consecutive irreversible first order reactions. It was pursued the influence upon the process of parameters such as: feed phase concentration, stripping phase concentration in the presence of two type carriers: tributyl phosphate (TBP) and trioctylphosphine oxide (TOPO). Depending on these transport parameters were calculated kinetics parameters such as: pseudo-first-order apparent membrane entrance and exit rate constants, the maximum flux at the entrance and exit out of the membrane. The highest values of the transport flux is obtained in the presence of carrier trioctylphosphine oxide (TOPO) at the concentration in the feed phase of 10-4 mol/L indole-3-acetic acid and a concentration of 10--2mol/L NaOH in the stripping phase.