Hollow Fiber Supported Liquid Membrane Research Articles

The use of factorial design for levulinic acid extraction via hollow fiber supported liquid membrane

Supported liquid membrane (SLM) is an effective method to separate a high-demand levulinic acid (LA) from an aqueous or biomass hydrolysate solution. Several factors can influence the separation of LA using SLM. In this study, three hollow fiber (HF) SLM (HFSLM) operation parameters, such as carrier concentration (0.1–0.5 M tri-n-octylamine, (TOA), stripping concentration (0.25–0.75 M sodium hydroxide (NaOH), and feed concentration (10–30 g/L LA) was analyzed by using a 23 full factorial design (FFD). The results showed that all three factors significantly impact the extraction of LA. The order of contribution effects towards LA extraction was LA feed concentration > NaOH stripping concentration > TOA carrier concentration. The design proposed a valid condition of factors such as 0.5 M TOA, 0.75 M NaOH, and 10 g/L of LA with LA extraction of 69.6 ± 2.16 %. The result proved that FFD effectively improved the LA extraction in the HFSLM process by considering all the factors involved.

Elimination of glufosinate ammonium from aqueous solution with hollow fiber supported liquid membrane and mathematical modeling

A hollow fiber supported liquid membrane (HFSLM) was used to extract and eliminate glufosinate ammonium from aqueous solution using TOA (tri-n-octylamine) in hexane and sodium hydroxide (NaOH) as carrier and stripping phase, respectively. Maximum extraction (∼76%) and stripping (∼75%) were achieved by feed solution at pH 1.0, temperature 60 °C, TOA concentration 6% (v/v) and NaOH concentration 1.0 M. The developed mathematical model exhibited high precision when predicting the concentration of glufosinate ammonium in raffinate solution and extraction percentage under different feed flow rates, with correlation coefficient (R 2) 0.9863.

The simultaneous elimination of arsenic and mercury ions via hollow fiber supported liquid membrane and their reaction mechanisms: Experimental and modeling based on DFT and generating function

This study investigates the simultaneous removal of low concentrations of arsenic and mercury ions from synthetic produced water via hollow fiber supported liquid membrane (HFSLM). Results show that HFSLM can remove both arsenic and mercury ions from synthetic produced water to less than 0.02 and 0.001 mg·L-1, respectively. These final concentrations comply with the wastewater standard of Thailand. Percentages of extraction for arsenic and mercury ions proved to be about 100 %. Those of recovery for arsenic and mercury ions reached 70 % and 75 %, respectively. A quantum model based on density functional theory (DFT) is introduced to analyze the forming and breaking of supramolecular complex species in the processes of extraction and recovery, respectively. Furthermore, the conceptof Generating Function is applied to construct a mathematical model forforecasting the potential of removing metal ions via HFSLM. The mathematical model conforms to the experimental data, having an average relative deviation of 5 %. The results of this study provide a better understanding of the transport mechanisms of arsenic and mercury ions.

Effect of Flow Operation Modes on Removal of Acetic Acid from Oil Palm Frond Biomass Hydrolysate using Hollow Fiber Supported Liquid Membrane

Acetic acid (AA) is considered an inhibitor in the oil palm frond (OPF) biomass hydrolysate solution. It can reduce the microorganism activity during sugar fermentation using OPF solution. In the current study, a hollow fiber supported liquid membrane (HFSLM) system using hybrid polyethersulfone-graphene membrane support and organic liquid membrane phase of 0.5 M tri-n-octyl amine carrier in a 2-ethyl-1-hexanol diluent was used to remove the AA. The liquid membrane impregnation time and the flow operation modes of the feed and strip phases in the HFSLM configuration were investigated. Mode I was operated with the feed phase flow inside the hollow fiber (HF) lumen and the stripping phase flow at the shell side. In mode II, the feed phase entered at the shell side and the stripping phase at the lumen of the HF support. The best liquid membrane impregnation time was 4 hours, exhibiting the highest AA removal efficiency of 80% compared to 1 and 24 hours of impregnation time. The removal efficiency of the AA was 80.1% and 42.4% using mode I and mode II, respectively, at 8 hours of the supported liquid membrane (SLM) running time. HFSLM was applied to remove AA from real OPF biomass hydrolysate. It was found that the AA concentration had reduced from 6.83 to 2.01 g/L after the SLM process. The SLM process did not affect the concentration of other components, especially sugar compounds in the OPF biomass hydrolysate.

Mechanisms of mercury ions separation by non-toxic organic liquid membrane via DFT, thermodynamics, kinetics and mass transfer model

This work focuses on the separation of mercury ions from synthetic produced wastewater via hollow fiber supported liquid membrane (HFSLM). Standard sunflower oil is used as a non-toxic extractant and solvent for mercury ions separation from wastewater. Under optimal conditions: 20 ppm NaCl in wastewater, 0.1 M thiourea in 0.5 M HCl as stripping solution, flow rates of feed and stripping solutions of 100 mL/min, and temperature 323 K, percentages of extraction and stripping reach 98% and 81%, respectively. The mechanisms of extraction and stripping reactions were investigated via the density functional theory (DFT). For the extraction, a linoleic acid extracted HgCl2 and formed halogen bond. For the stripping, two protonated thiourea stripped HgCl2 and formed covalent and halogen bonds. According to the thermodynamics study, extraction reaction is found to be endothermic (ΔHEx0 = 1,001.00 J/mol), irreversible (ΔSEx0 = 3.45 J/mol K), and spontaneous, (ΔGEx@323K0 = −112.65 J/mol). Finally, the mathematical model including conservation, convection, diffusion, reaction, and accumulation was developed. The differences of mercury ions concentration in feed and stripping phases from the experiments and the predicted data from the mathematical model were 5% and 2%, respectively indicating that the model is acceptable.

Hollow Fibre-Supported Liquid Membrane for the Determination of Sulfonamide Residues in Egg Samples

In this study, a three-phase hollow fibre-supported liquid membrane (HF-SLM) technique incorporated with high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD) was developed for the extraction, clean-up, and determination of fifteen sulfonamide residues in chicken egg samples. The residues were extracted from the 5 mL sample solution of pH 2.5 into a thin layer of organic phase (1-octanol with 10% TOPO) immobilised in hollow fibre pores and then back-extracted into approximately 6 μL of aqueous phase (pH 13) located in the lumen of the hollow fibre. After extraction, 6 μL of the acceptor phase was injected into an HPLC instrument for subsequent analysis. Under optimum conditions, the limit of detection (LOD) and limit of quantification (LOQ) values ranged from 0.8–7.9 μg·kg−1 and from 2.4–21.0 μg·kg−1, respectively, linearity in the range of 5 1 000 μg·kg−1, and intra- and inter-day precision (%RSD) values at three concentration levels (50, 100, and 500 μg·L−1) ranged from 6.2–15.7%, 7.3–15.0%, and 7.3–14.6%; and 6.4–17.4%, 4.3–16.2%, and 8.3–16.5%, respectively, were obtained. The accuracy of the method, expressed as percentage recovery, was in the range of 71.0–98.7%, with corresponding %RSD (n = 6) values ranging from 1.9–9.9% being obtained. The developed method provided enrichment factors in the range of 17.1 to 541.4. The applicability of the proposed method was also evaluated by analysing egg samples, which were randomly collected from local supermarkets located in Gauteng Province, South Africa. The results obtained revealed that the developed method has the potential to be used as an alternative method for the determination of sulfonamide residues in egg and related complex samples.

Separation of lanthanum and neodymium in a hollow fiber supported liquid membrane: CFD modelling and experimental validation

Nickel metal hydride batteries find extensive use in many electronic devices. They contain a small amount of rare earth elements, such as, lanthanum and neodymium, which can be recovered from waste batteries, and reused. Hollow fiber supported liquid membranes (HFSLM) have been used for separation of different metal ions. In this work, a CFD model has been developed for a HFSLM to study the separation of lanthanum ion (La+3) and neodymium ion (Nd+3) from an aqueous solution. The model considers the effect of pH on distribution coefficient DM, which is a function of hydrogen ion (H+) concentration, and has a significant effect on extraction efficiency. The model was validated with the experimental data. An empirical model was fitted with the simulation data, and the parameters were optimized for the effective separation of La+3 and Nd+3. The maximum extraction of Nd+3 was predicted to be 44.97%, whereas extraction of La+3 was estimated to be 3.39%, at the optimized conditions of flow rate: 118.96 ml/min, feed pH: 3.41, and [PC88A]: 41.63 mol/m3, in once-through mode. The proposed CFD model could be helpful in design as well as, scale-up of HFSLM for separation of metal ions, by changing the design and process parameters.

Application of solubility data on a hollow fiber supported liquid membrane system for the extraction of gold (I) cyanide from electronic industrial wastewater

The solubility ternary system was used to develop a hollow fiber-supported liquid membrane process for the extraction of gold (I) cyanide from electronics industry wastewater. Five kinds of diluents (p-xylene, cyclohexene, 1-dodecanol, n-heptane, and n-dodecane) were applied to the solubility of ternary systems (Aliquat336 + water + diluents) at 303.2 K and atmospheric pressure. 1-dodecanol, p-xylene, and cyclohexane were selected because they are completely soluble in Aliquat336 in any composition. The effects of pH on the feed solution and type of diluent were examined. The highest extraction and stripping percentages of 99.9 and 61.4, respectively, were achieved at a feed solution pH of 10.0 using p-xylene as the best diluent.

Selective separation of trace nickel(II) and gold(I) ions via hollow fiber supported liquid membrane enhanced by synergistic extractants D2EHPA/TBP

This work presents the selective and simultaneous separation of nickel (Ni2+) and gold ([Au(CN)2]−) ions, in trace amounts, from alkaline solution via hollow fiber supported liquid membrane (HFSLM) technique. HFSLM is challengingly carried out in real rinse wastewater generated by the ENIG plating process. The influence of various chemical parameters, including the type of extractant and their concentrations, molar ratios of mixed extractant as well as type of strippant, are also studied. The organophosphorus extractant mixtures of D2EHPA and TBP provide a synergistic effect for target Ni2+ ions but has an antagonistic effect as regards the extraction of non-target [Au(CN)2]− ions. Compared to other inorganic acids, HCl is seen to be the most suitable strippant for the selective stripping. Results demonstrate that percentages of extraction and stripping of Ni2+ ions achieved 85.7 and 83.2%, respectively. In contrast, percentages of extraction and stripping of non-target [Au(CN)2]− ions attained 15.6 and 1.94%.

The elimination of trace arsenic via hollow fiber supported liquid membrane: experiment and mathematical model

This work presents the elimination of arsenic ions from synthetic produced water via hollow fiber supported liquid membrane (HFSLM). Results demonstrate that arsenic ions in synthetic wastewater can be successfully treated to meet the wastewater standard as formulated by the Ministry of Industry and the Ministry of Natural Resources and Environment, Thailand. The discharged limit of arsenic from industrial wastewater must not be greater than 250 ppb. In a single-step operation, arsenic ions are extracted and stripped. Percentages of extraction and stripping proved to be 100% and 98%, respectively. Optimum conditions found proved to be 0.68 M Aliquat 336 dissolved in toluene as the liquid membrane, at pH 12 of feed solution, having a mixture of HCl and thiourea as the synergistic strippant, and flow rates of both feed and strippant solutions of 100 mL/min. A mathematical model, developed to predict the final concentration of arsenic ions in feed and strippant solutions, is seen to fit in well with the experimental results.

A systematic study on extraction and separation of scandium using phosphinic acid by both solvent extraction and hollow fibre membrane

ABSTRACT A method for separation of scandium and preparation of scandium oxide using hollow fibre supported liquid membrane (HFSLM) was described. Scandium was separated from a multi metal solution bearing copper, nickel, cobalt, zinc, iron, manganese and scandium using bis (2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) as the mobile carrier. The effect of parameters such as pH, extractant concentration, flow rate, metal ion concentration and strip solution concentration on extraction of scandium was investigated and maximum flux was obtained at pH 2.0, Cyanex 272 concentration of 0.3 M, flow rate of 240 mL/min and 1.0 M H2SO4 in strip solution. From the equilibrium studies the extracted species was determined to be ScR3.3RH. A comparative study between solvent extraction and HFSLM has also been carried out to predict the efficiencies of both the techniques for the present system which could be useful for the treatment of industrial wastes bearing very low amount of Sc. It was observed that Sc recovery using Cyanex 272 with HFSLM and solvent extraction was 99.9 and 91%, respectively. Scandium was separated from other metal ions with high separation factors which followed the trend Sc/Ni < Sc/Mn < Sc/Co < Sc/Zn < Sc/Fe < Sc/Cu. High pure scandium oxide (Scandia) was prepared from the strip solution by precipitation with oxalic acid and thermal decomposition at 750°C for 1 h.

Separation of homogeneous palladium catalysts from pharmaceutical industry wastewater by using synergistic recovery phase via HFSLM system

Separation of homogeneous palladium catalysts from pharmaceutical industry wastewater by using synergistic recovery phase via hollow fiber supported liquid membrane (HFSLM) system is presented. HFSLM impregnated with N-methyl-N,N,N-trioctylammonium chloride (Aliquat 336) as the extractant dissolved in cyclohexane. The influence of various chemical parameters, including the concentration of extractant and recovery phases as well as recovery selector concentration in recovery phase, were also studied. A mixture of hydrochloric acid and thiourea was used as synergistic recovery phase. The highest percentage of extraction and recovery was 99.95% and 88.12%, respectively. Furthermore, the kinetics of recovery reaction was studied to provide reaction order, reaction rate constant, equilibrium constant and distribution ratio.

Separation of methylparaben from aqueous source stream by pseudo-emulsion hollow fiber membrane strip dispersion technique: Optimization of process parameters using Grey-Taguchi method

Parabens are the esters of p-hydroxybenzoic acid extensively used as antimicrobial preservatives in food, pharmaceuticals and personal care products. These compounds have been reported to have estrogenic and antiandrogenic properties. The separation of methylparaben from water by hollow fiber supported liquid membrane (HFSLM) and pseudo-emulsion hollow fiber membrane strip dispersion (PEHFSD) technique was studied. Output responses: permeability and stripping percentage were maximized by Grey-Taguchi technique. Concentrations of methylparaben in the three phases at equilibrium were in good agreement with the values calculated from the material balance. Stripping percentage for HFSLM and PEHFSD system were 67% and 90.52% respectively at a contact time of 90 minutes. The estimated permeability was 3.8859 × 10−5 and 7.8041 × 10−5 cm/sec for HFSLM and PEHFSD system respectively.

Removal of paraquat from aqueous media via HFSLM and mathematical modeling

The removal and recovery of paraquat from an aqueous solution using a hollow fiber supported liquid membrane (HFSLM) was performed. The extractant was Di-(2-ethylhexyl) phosphoric acid (D2EHPA) which was dissolved in kerosene, whereas the recovery solution was a hydrochloric acid solution. It was found that the pH concentration of D2EHPA, concentration of hydrochloric acid at 8, 4% (v/v), and 1.0 M, respectively, were the optimum conditions. In the one-through mode, 70% and 68% of extraction and recovery, respectively, were achieved, while 99% extraction and recovery were obtained in the circulated mode. In addition, the mathematical model can predict the concentration of paraquat in raffinate solution with different paraquat concentrations and flow rates of feed solution with the R2 of 0.923 and 0.843, respectively.

Extraction of Zinc in Presence of Cobalt through Hollow Fibre Supported Liquid Membrane from Simulated Industrial Wastewater

Many industrial wastewaters contain toxic metals such as zinc, chromium, cobalt in the form of fluorides and nitrates as anions. Transport of Zn 2+ from simulated industrial wastewater was studied using di-2-ethylhexyl phosphoric acid (D2EHPA) diluted in kerosene as the organic phase. The hollow fibre supported liquid membrane was operated in continuous recycle mode. Effect of feed phase pH, carrier concentration, sulphuric acid concentration in the strip phase, and flow rate on Zn 2+ transport was examined. The feed phase pH was varied in the range of 1.5–2.5. The organic phase concentration was varied in the range of 10-30 %. At the feed phase pH of 2, the extraction rates were found to be high. About 12% rise in mass transfer flux of Zn 2+ ions was observed with an increase in D2EHPA concentration from 10% to 20%. The mass transfer flux of Zn 2+ ions was found to be increased by 28% with an increase in sulphuric acid concentration from 0.5 M to 1 M. The flow rate variation study suggests that mass transfer resistance is mainly contributed by diffusion mechanism through the membrane.

Computational fluid dynamics modeling of uranium(VI) transport through hollow fiber supported liquid membrane

ABSTRACT Uranium(VI) ions transport through hollow fibre supported liquid membrane (HFSLM) using TBP (tri-n-butyl phosphate) in n-dodecane as the extractant and 0.01 M HNO3 as strippant is modelled by using Computational Fluid Dynamics (CFD) model for once-through the mode of operation. The model solves the momentum transport equation for the feed on the lumen side and the stripping phase on the shell side. The species transport equation is solved for the feed on the lumen side, the liquid membrane phase within the pores of the lumen and the stripping phase on the shell side. The boundary conditions of flux continuity and concentration jump at the feed-liquid membrane and the liquid membrane–strip interfaces are implemented. The results obtained from the CFD model at different parametric conditions are compared with the experimental data and found a good agreement between them. Validated CFD model is used to have in-depth insights into mass transfer phenomena at different hydrodynamic and chemical conditions. The effect of geometry on mass transfer is also evaluated. Overall this study will give valuable input to the supported liquid membrane (SLM) processes using hollow fibre contactor in the optimization of process design, operation and scale-up.

A Critical Study of the Effect of Polymeric Fibers on the Performance of Supported Liquid Membranes in Sample Microextraction for Metals Analysis.

Popularity of hollow fiber-supported liquid membranes (HF-SLM) for liquid-phase microextraction (HF-LPME) has increased in the last decades. In particular, HF-SLM are applied for sample treatment in the determination and speciation of metals. Up to the date, optimization of preconcentration systems has been focused on chemical conditions. However, criteria about fiber selection are not reflected in published works. HFs differ in pore size, porosity, wall thickness, etc., which can affect efficiency and/or selectivity of chemical systems in extraction of metals. In this work, Ag+ transport using tri-isobutylphosphine sulfide (TIBPS) has been used as a model to evaluate differences in metal transport due to the properties of three different fibers. Accurel PP 50/280 fibers, with a higher effective surface and smaller wall thickness, showed the highest efficiency for metal transport. Accurel PP Q3/2 exhibited intermediate efficiency but easier handling and, finally, Accurel PP S6/2 fibers, with a higher wall thickness, offered poorer efficiency but the highest stability and capability for metal speciation. Summarizing, selection of the polymeric support of HF-SLM is a key factor in their applicability of LPME for metals in natural waters.

A numerical and experimental investigation on the selective separation of Pd (II) from wastewater using Aliquat 336 via hollow fiber supported liquid membrane

Abstract The separation of palladium (Pd (II)) from wastewater containing copper (Cu (II)) and nickel (Ni (II)) is investigated via hollow fiber supported liquid membrane (HFSLM). The viability to separate Pd (II) is established by controlling the influence of operating conditions. Under optimized conditions viz. 6%(v/v) of Aliquat 336, pH 2 of feed solution, 0.5 M of thiourea mixed with 0.1 M HCl as a strippant and 100 mL/min of flow rate for both aqueous solutions, extraction and stripping of Pd (II) reach >99 % and 87.09 %, respectively. In order to determine stoichiometric coefficients, slope analysis is employed. To study the transport phenomena of Pd (II) across HFSLM, an analysis of mass is presented. Axial convection, axial diffusion, radial diffusion and chemical reactions are investigated via mathematical modeling. Results indicate that the model proves to be an effective approach for predicting the transportation of Pd (II) across the system.

Studies on the Removal of Endocrine-Disrupting Compounds From Aqueous Streams by Emulsion Liquid Membrane and Hollow Fiber Supported Liquid Membrane

Endocrine disrupting compounds (EDC) possess xenobiotic and exogenous roots which limits the natural functioning of the endocrine system like synthesis, secretion, transference and binding in animals and human being. Humans, animals and industries discharges EDC to soil, surface/ground water and sediments mostly through sewage treatment system. Studies have shown the impact of EDC on nervous system, lungs, liver, thyroid, prostate, reproductive system, metabolism, obesity etc. So removal of these compounds by suitable processes is necessary. Conventional techniques like coagulation, precipitation, flocculation, microfiltration, ultrafiltration etc. are not are not that much effective for the removal of EDC having low molecular weight and are also limited by the pore sizes. The current study emphases on the use of techniques like Emulsion liquid membrane and Hollow fiber supported liquid membrane which are the promising techniques for the removal of EDC from aqueous streams. The working and implementation of these two techniques in the removal of several EDC from aqueous streams are also discussed.

Selective solvent bar micro-extraction as a single-step approach for the measurement of Cu fractions in seawater.

Hollow fibre-supported liquid membrane was used for Cu fractionation in marine waters, using di-2-pyridylketone benzoylhydrazone (dPKBH) as a carrier due to its capacity to transport dissolved inorganic Cu at natural seawater pH. Optimized conditions were dPKBH (0.5mmolL-1), HNO3 (0.5molL-1) as acceptor agent, extraction time of 120min and stirring speed of 800rpm. Additionally, the selectivity of the method for the extraction of the inorganic Cu fraction was validated by comparing the experimental results with theoretical data, and a mathematical model was obtained for estimation of Cu linked to dissolved organic matter. The method was applied for the measurement of Cu fractions in real seawater samples. Results were successfully compared with the reference material BCR 403 and recovery analysis in waters from the Gulf of Cádiz, showing that it could be used as a simple approach for the study of different Cu fractions in marine waters. Graphical abstract.