Sheet Supported Liquid Membrane Research Articles

Separation of Neodymium (III) and Lanthanum (III) via a Flat Sheet-Supported Liquid Membrane with Different Extractant-Acid Systems.

The increasing demand for neodymium (Nd) permanent magnets in electric motors has revived research interest of Nd recovery and separation from other rare earth elements (REEs). Typically, Nd/La separation is necessary for Nd recovery from primary ores and secondary resource recycling. This research used a flat sheet-supported liquid membrane (FSSLM) with different extractant-acid systems to extract Nd from a Nd/La mixture. The recovery and separation of Nd/La with 204P-H2SO4, 507P-HCl, and TBP-HNO3 were discussed. The results showed effective Nd recovery and promising Nd/La selectivity could be achieved in the 507P-HCl system, compared to 204P-H2SO4 and TBP-HNO3. The addition of citric acid to the feed solution was effective for pH buffering but did not improve the Nd transport or Nd/La selectivity. Long-term stability of the 507P-HCl extractant system was demonstrated by extending the processing time from 6 h to 6 days.

Recycling of Lithium‐Ion Batteries – Modeling Using Flat Sheet Supported Liquid Membranes

AbstractTo meet the world climate goals, sustainable and efficient technologies will be required. Lithium‐ion batteries (LIBs) emerge as state‐of‐the‐art power sources for all modern consumer electronic devices. This way, the recovery of components plays an important role in the spent LIBs recycling processes. Also, the challenge of research and development of industries is to develop a high number of valuables using the minimum number of experiments, providing low‐cost processes. Two models to be employed in flat sheet supported liquid membranes (FSSLMs) to estimate the behavior of ion concentrations during operation are proposed. Applying the simplified model it is possible to predict the behavior of the system, based on few experiments. This advance can be exciting in industry, such as in the lithium recovery from LIBs using membranes.

Prediction of Nickel Removal using Diffusion Model in Flat Sheet Supported Liquid Membrane

Supported liquid membrane (SLM) is one of the potential extraction methods for the treatment of wastewater containing various toxic heavy metal ions. Advantageously, this process offers simultaneous removal and recovery, as well as low energy consumption and operational cost. In this study, the prediction of nickel removal was investigated using a diffusion model developed through MATLAB.

Pertraction of Nd(III) and U(VI) Through Flat Sheet Supported Liquid Membrane Containing N, N’-Dimethyl-N, N’-Dioctyl-3-Oxadiglcolamide as Carrier

ABSTRACT In this paper, pertraction of Nd(III) and U(VI) from nitric acid media through a flat-sheet supported liquid membrane (FSSLM) was studied by using a self-made liquid membrane device, respectively, with N, N’-dimethyl-N, N’-dioctyl-3-oxadiglcolamide (DMDODGA) diluted in 40/60 (V/V)% n-octanol/kerosene as the carrier. The effects of various factors, such as the acidity of the feed and stripping phases, neodymium concentration, uranium concentration, DMDODGA concentration are discussed. The optimized conditions for Nd(III) transport were found to be 3 M HNO3 in the feed phase, 0.5 M HNO3 in the stripping phase, 0.48 M DMDODGA in n-octanol/kerosene as the carrier. When the initial concentration of Nd(III) was 1 × 10−4 mol/L, the transport rate of Nd(III) was 86.4(±2.2)%. Compared with Nd(III), the liquid membrane was less effective in the transport of U(VI), the highest transport rate of U(VI) was 57.2 (±2.6)%.

Non-dispersive selective extraction of germanium from fly ash leachates using membrane-based processes

ABSTRACTNon-dispersive selective extraction of Ge(IV) tartrates was carried out from simulated fly ash solutions containing heavy metals through supported liquid membranes (SLM). The optimum transport was obtained using a PTFE membrane containing Alamine 336 5%v/v in the condition of tartaric acid 2.76 mmol/L and HCl 1 mol/L in feed and strip phases, respectively. Under this condition, a hollow fiber (HF) SLM experiment was conducted. The results showed that this system could transport germanium from the feed to the strip phase so much faster than the flat sheet (FS) SLM system. The rate of transport through HFSLMs is comparable to dispersive extractions.Abbreviation: A: Effective area of the membrane (cm2); BDL: Below detection limit; Cf,: Feed concentration (mg/L); Ct,: Initial concentration (mg/L); D: Distribution coefficient; ELM: Emulasion liquid membranes; FSSLM: Flat sheet supported liquid membrane; HF: Hollow fiber; LLX: Liquid-liquid extraction; P: Permeation coefficient (m/h); PTFE: Poly tetra fluoro ethylene; PVDF: Polyvinylidene difluoride; T: Tartrate species (C4H4O6); T: Temperature (K); %T:Germanium transport effeciency; V: Volume of feed solution (cm3); t: time (h); η: Viscosity (P.s (c.P)); κ: Boltzmann constant; r: Ionic radius of species; τ: Tortuosity of the membrane; ρ: Porosity; α: Separation factor.

Pertraction of americium(III) through supported liquid membranes containing benzene-centered tripodal diglycolamides (Bz-T-DGA) as an extractant/carrier

Two novel benzene-centered tripodal diglycolamide (Bz-T-DGA) ligands with affinity for actinide ions were employed for the solvent extraction as well as flat sheet supported liquid membrane (SLM) transport of trivalent americium (Am3+), considered as one of the most important minor actinide ions in the high level waste (HLW). Bz-T-DGA ligands with isopentyl substituents and varying spacer lengths in the DGA arms, viz. methylene (TPAMTEB) and ethylene (TPAETEB) groups were employed for actinide extraction for possible application in nuclear waste remediation. With both the ligands, the extraction of Am3+ increased with the concentration of nitric acid (1–6MHNO3), the distribution ratio (D) values being 16.6 and 3.71 at 3M HNO3 and 35.1 and 44.4 at 6M HNO3 for 6.6×10−4M TPAMTEB and TPAETEB, respectively taken in a 5% isodecanol and 95% n-dodecane diluent mixture. A stripping study showed a relatively slow stripping of Am3+ from the loaded membrane with TPAETEB even in the presence of a complexing agent. Am3+ transport rates were rather slow in polypropylene (PP) flat sheets as compared to previous, analogous studies suggesting slow migration of the complexed ions. Am3+ transport was 4.8 times slower in TPAETEB than in TPAMTEB with diffusion coefficients of 4.5×10−8 and 2.16×10−7cm2/s, respectively.

Effect of hydrophobic and hydrophilic nanoparticles loaded in D2EHPA/M2EHPA - PTFE supported liquid membrane for simultaneous cationic dyes pertraction

Cationic dyes mixture pertraction experiments of Rhodamine B (RhB) and Methylene Blue (MB) using a flat sheet supported liquid membrane (SLM) were performed. Mono-(2-etylhexyl) ester of phosphoric acid (M2EHPA) and bis-(2-etylhexyl) ester of phosphoric acid (D2EHPA) mixture was used as carrier and Sesame oil to dilute the carrier due to its very high viscosity. Acetic acid (AA) was also used as stripper phase. Influences of hydrophobic and hydrophilic nanoparticles were loaded in a carrier at different loadings (from 0 to 6 mg mL−1) on dyes pertraction at constant operating conditions were investigated. It was found that hydrophilic nanoparticles, including ZnO and TiO2 decrease dyes pertraction, while hydrophobic nanoparticles, including ZIF-8 and Fe3O4 favorably increase this parameter. ZIF-8 was found as the most effective nanoparticles on increasing dyes pertraction and the optimum loading was 2 mg mL−1. Also, the important process parameters that influence on the dyes mixture pertraction efficiency such as feed concentration, carrier concentration, feed pH and strip concentration were studied. In order to investigate the effects of operating parameters, all experiments were performed at a constant 2 mg mL−1 ZIF-8 loading. Optimum pertraction efficiency of RhB and MB were 90.6 and 79.4%, respectively. They were obtained after 10 h pertraction at optimum experimental conditions with feed concentration of 100 mg L−1, carrier concentration of 35% (vol), strip concentration of 0.5 mol L−1, and feed pH of 6. Effect of time on pertraction efficiencies at the optimum conditions were also studied.

Liquid-liquid extraction and facilitated transport of f-elements using an N-pivot tripodal ligand

Diglycolamide (DGA)-functionalized tripodal ligands offer the required nine-coordinated complex for effective binding to a trivalent lanthanide/actinide ion. A N-pivot tripodal ligand (TREN-DGA) containing three DGA pendant arms was evaluated for the extraction and supported liquid membrane transport studies using PTFE flat sheets. Solvent extraction studies indicated preferential extraction of 1:1 (M:L) species, while the metal ion extraction increased with increasing HNO3 concentration conforming to a solvated species extraction. Flat sheet-supported liquid membrane studies, carried out using 4.0 × 10−3 M TREN-DGA in 95% n-dodecane + 5% iso-decanol indicated faster mass transport for Eu3+ ion as compared to Am3+ ion. The determined transport parameters indicated slow diffusion of the M-TREN-DGA (M = Am or Eu) complex being the rate-determining step. The transport of lanthanides and actinides followed the trend: Eu3+ > Am3+∼ Pu4+ >> UO22+ and Am can be selectively separated from a mixture of U and Pu by oxidizing the latter to its +6 oxidation state. The liquid membrane stability was not encouraging and was deteriorating the transport efficiency with time, which was attributed to carrier loss into the aqueous phases.

Novel amine modification of ZIF-8 for improving simultaneous removal of cationic dyes from aqueous solutions using supported liquid membrane

Effect of amine modification of ZIF-8 on pertraction of mixed Rhodamine B (RhB) and Methylene blue (MB) cationic dye in aqueous solution was studied using flat sheet supported liquid membrane (SLM). Mixtures of mono-(2-etylhexyl) ester of phosphoric acid (M2EHPA), bis-(2-etylhexyl) ester of phosphoric acid (D2EHPA) and nanoparticles were used as carrier and Sesame oil as diluent. Microporous hydrophobic PTFE membrane was used as support for liquid membrane, and strip phase was acetic acid. It was found that loading of amine modified ZIF-8 nanoparticles in carrier, increases the dyes pertraction efficiency more than the pristine ZIF-8 nanoparticles and the optimum loading was obtained as 2000mgL−1.Response surface methodology (RSM) based on Box-Benken design (BBD) with optimum amine modified ZIF-8 nanoparticles loading was used to design the experiments and analyze the effects of three major operating parameters including feed concentration, carrier concentration and initial feed phase pH. The optimum pertraction efficiency for MB and RhB were found as 88.3 and 99.1% respectively and obtained after 10h in feed concentration of 100mgL−1, carrier concentration of 35 vol.% and initial feed phase pH of 6.

Transport of Zn(II), Fe(II), Fe(III) across polymer inclusion membranes (PIM) and flat sheet supported liquid membranes (SLM) containing phosphonium ionic liquids as metal ion carriers

ABSTRACTIn this work transport of Zn(II), Fe(II) and Fe(III) ions from chloride aqueous solutions across polymer inclusion membranes (PIMs) and supported liquid membranes (SLMs) containing one of three phosphonium ionic liquids: trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104) and tributyl(tetradecyl)phosphonium chloride (Cyphos IL 167) as an ion carrier was reported. The results show that Zn(II) and Fe(III) are effectively transported through PIMs and SLMs, while Fe(II) transport is not effective. The highest values of initial flux and permeability coefficient of Zn(II) were noticed for SLM containing Cyphos IL 167. Cyphos IL 101-containing SLM is more stable than PIM.

Pertraction of l-lysine by supported liquid membrane using D2EHPA/M2EHPA

In this paper, an experimental study regarding pertraction of l-lysine monohydrate (l-lys) was investigated in an aqueous medium through a flat sheet supported liquid membrane (SLM) using a mixture of mono-(2-etylhexyl) ester of phosphoric acid (M2EHPA) and bis-(2-etylhexyl) ester of phosphoric acid (D2EHPA) as carriers and kerosene as diluent. Microporous hydrophobic PTFE membrane was used as support for the liquid membrane, and the strip phase was hydrochloric acid. The parameters affecting pertraction of l-lys, such as feed concentration, carrier concentration, initial feed pH, and stripper concentration were analyzed. It was found that these parameters strongly influence pertraction efficiency. Optimal experimental conditions for l-lys pertraction (pertraction efficiency of 33.4%) were obtained after a 4h separation with l-lys feed concentration of 150ppm, carrier concentration in the membrane phase of 35vol.%, initial feed phase pH of 3, and hydrochloric acid concentration in the strip phase of 1M. Stability of the SLM system was also studied. According to the stability experiments, it was observed that reduction of pertraction efficiency after 8h is less than 6.8%.

PHENOLIC WASTEWATER TREATMENT BY SUPPORTED LIQUID MEMBRANE USING DIFFERENT COOKING OILS AS LIQUID MEMBRANE

Transport of phenol through a flat sheet supported liquid membrane (SLM) containing cooking oil as liquid membrane (LM) was investigated. Factors affecting permeation of phenol such as membrane phase, support material, feed phase pH, stripping phase concentration, stirring speed, and initial concentration of phenol were studied. It was found that these parameters strongly influence phenol removal efficiency; PTFE membrane as support material, grape seed oil as liquid membrane, feed pH of 2.0, initial phenol concentration of 100 mg/L, stirring speed of 350 rpm, and 0.2 M sodium hydroxide as effective stripping agent were found as the best conditions for greater phenol transport. Under these conditions, permeability was found to be 7.46 × 10−6 m/s. After 10.5 h, phenol was completely removed from the feed phase to strip phase. According to stability experiments, it was observed that the SLM is stable after 22 h. Thus, the use of cheap, nontoxic, and naturally oil as a novel and green membrane for recovery of phenol from wastewater was demonstrated.

Extraction of Lignosulfonate using TOA-Kerosene-PVDF in Supported Liquid Membrane Process

Lignosulfonate is a major byproduct from the sulphite pulping process which is the most abundant biopolymer and largely unused. Although lignosulfonate is nontoxic, it impacts brownish black colour to water and makes the water unsuitable for reuse. However, lignosulfonate have a wide range application, such as production of vanillin, animal feed pellets binder and pesticides. Therefore, an efficient separation technique of lignosulfonate from the wastewater is necessary in order to meet the wastewater treatment requirement and as a source of valuable material for industrial applications. In this study, lignosulfonate was extracted from aqueous solution through flat sheet supported liquid membrane (SLM) using trioctylamine (TOA) as carrier. SLM has great potential for the separation lignosulfonate as it offers advantages such as simultaneous extraction and stripping steps, low consumption of carrier and high selectivity. The important parameters governing the extraction process are the types of support material, types of solvents, types of stripping agent, feed phase flow rate and pH were investigated. The favorable condition for extraction was obtained by using TOA-Kerosene-PVDF membrane system, 0.5M NaOH as stripping agent, 100 mL/min of flow rate and feed at pH 2 with 37.5% of lignosulfonate removal. The result demonstrated that the membrane support remains stable for more than 9 hours, hence demonstrating promising separation technique for lignosulfonate.

Supported liquid membrane-based simultaneous separation of cadmium and lead from wastewater

This work is aimed at the investigation of simultaneous extraction and recovery of heavy metals (cadmium and lead) from aqueous solutions through a coconut oil-based Flat Sheet Supported Liquid Membrane (FS-SLM). Environmentally benign nature of coconut oil is the prime advantage in this technique. N-Methyl-N,N-dioctyloctan-1-ammonium chloride (Aliquat 336) is an ideal carrier agent for the transportation of the said heavy metals. Ethylenediaminetetraacetic acid (EDTA) was selected as stripping agent keeping in view its metal chelating capacity. Initially, the performance of Supported Liquid Membrane (SLM) was investigated only for the transportation of cadmium, or precisely Cd(II). A porous polymeric solid membrane viz., polyvinylidene fluoride (PVDF) was used as a support in order to hold and contain the membrane liquid in the SLM structure. The size of the pores in the support is 0.2μm. The effects of various operating conditions viz. concentration of the carrier in membrane phase, concentration of stripping agent, pH of feed phase etc. were studied. The optimum process conditions for the transportation of Cd(II) were: 0.5% (v/v) Aliquat 336 in coconut oil as membrane phase, 0.015M EDTA as stripping agent, and pH of 6.5 in the feed phase. The initial feed concentration was 5ppm and the total transportation time was 10h. Transportation of another heavy metal viz., lead (Pb) was also carried out with the above optimum process conditions. Finally, simultaneous transportations of both metals (lead and cadmium) were studied with various molar ratios (Cd:Pb) in the feed. The optimum extraction and recovery of cadmium were found as 79% and 67%, respectively, and that of lead were found as 84% and 78%, respectively, in simultaneous transportation. Lead was observed to be preferentially transported through SLM due to its favorable electronic configuration.

Recovery of acetaminophen from aqueous solutions using a supported liquid membrane based on a quaternary ammonium salt as ionophore

AbstractA flat sheet-supported liquid membrane (FSSLM) system, consisting of an ionic liquid, tricapryl-methylammonium chloride (Aliquat 336®) in octan-2-ol, is proposed as a means of recovering acetaminophen (Ac) from aqueous solutions; Ac is an active ingredient widely used in many pharmaceutical preparations. Several parameters which could affect the transport efficiency were examined, i.e., the strippant nature and concentration in the receiving solution, the diluent nature, carrier concentration, initial acetaminophen concentration in the feed solution, and the polymeric support type. A facilitated transport was obtained by impregnating the polymeric support with 10 vol. % of Aliquat 336® in octan-2-ol, 1 M NaOH as a receiving solution, and a feed solution of Ac dissolved in ultrapure water. The study was completed by using the FSSLM thus developed for extracting Ac from some drugs in frequent use in Tunisia (Analgan®, Doliprane®, and Fervex®).

Transportation of bioactive (+) catechin from its aqueous solution using flat sheet supported liquid membrane

Transport of (+) catechin through a flat sheet Supported Liquid Membrane (SLM) has been investigated and reported in this paper. Liquid membrane (LM) was composed of carrier, tributyl phosphate (TBP) dissolved in aliphatic n-decane. Aqueous feed solution containing catechin was maintained at acidic (pH=4) condition using 0.1N HCl whereas ethanol was used as stripping agent. The SLM operation yielded 53% extraction and 49% recovery of the catechin at the optimum operating conditions viz. 100mgL−1 initial feed concentration, 1.2M TBP in the membrane phase, 0.4M ethanol as stripping agent, 200rpm stirring speed and 25°C temperature. The SLM method was found reasonably stable using polyvinylidene difluoride (PVDF) as a support material that allows repeatability of use of same support-LM combination. Further, the above transport method was tested for the recovery of catechin compounds present in hot water extract of green tea leaves which contains mainly (+) catechin (65.6%) and (-) epigallocatechin (EGC) (33.8%). Thirty six percent of catechin compounds initially present in the tea leaves extract (269.3mgL−1) was recovered at the optimum conditions which were slightly different from the optimum conditions achieved for synthesized catechin solution. Initial flux of transport for catechin compounds from tea leaves extract was found to be 19.17×10−9gcm−2s−1.

Supported liquid membrane transport studies on Am(III), Pu(IV), U(VI) and Sr(II) using irradiated TODGA

Transport behaviour of actinides viz. Am3+, Pu4+ and UO22+ was investigated from nitric acid feed conditions using PTFE (polytetrafluoroethylene) flat sheet supported liquid membranes (SLM) containing an irradiated solvent system comprising of N,N,N′,N′-tetra-n-octyldiglycolamide (TODGA) as the carrier extractant and N,N-di-n-hexyloctanamide (DHOA) as the phase modifier. The present studies were carried out in order to understand the effect of irradiation on the long term reusability of the SLM and the decontamination behaviour in the absorbed dose range of 0–100MRad. The studies using irradiated carrier included those with irradiated TODGA without any phase modifier and with 0.1M as well as 0.5M DHOA as the phase modifier. Transport behaviour of all the metal ions were found to be seriously affected with increasing radiation dose which was reflected in the decreasing percentage transport (%T) as well as permeability co-efficient (P) values. Though Sr(II) transport was quite significant with all the three unirradiated solvent systems, it was surprisingly low (<5%) when solvents exposed to 100MRad dose were used in the SLM. Separation factors (S.F.) of the actinides over Sr(II) were calculated and were found to increase at higher radiation doses suggesting possibility of getting better decontamination on prolonged use of the supported liquid membrane system.

Carrier Facilitated Transport of Europium(III) Across Supported Liquid Membranes Containing N,N,N′,N′-tetra-2-ethylhexyl-3-oxapentane-diamide (T2EHDGA) as the Extractant

Studies on the solvent extraction and pertraction behavior of europium(III) was carried out from acidic feed solutions using N,N,N′,N′-tetra-2-ethylhexyl-3-oxapentane-diamide (T2EHDGA) in n-dodecane as the solvent. The nature of the extracted species from the solvent extraction studies conformed to Eu(NO3)3 · 3T2EHDGA which is in variance with the analogous Eu(III) – TODGA (linear homolog of T2EHDGA) extraction system. The transport behavior of Eu(III) was investigated from a feed containing 3.0 M HNO3 into a receiver phase containing 0.01 M HNO3 across a PTFE flat sheet supported liquid membrane (SLM) containing 0.2 M T2EHDGA in n-dodecane as the carrier solvent and 30% iso-decanol as the phase modifier. Effects of feed acidity, carrier extractant concentration, membrane pore size, and Eu concentration in the feed on the transport rates of Eu(III) were also investigated. Membrane diffusion coefficient (D o) for the pertracted species was calculated using the Wilke-Chang equation as 4.25 × 10−6 cm2 · s−1. The influence of Eu concentration on the flux was also investigated. The role of temperature on the transport rates was investigated and the thermodynamic parameters were calculated.

The Extraction of Cr(VI) by a Flat Sheet Supported Liquid Membrane Using Alamine 336 as a Carrier

Chromium compounds have received considerable attention because they have been used extensively in such industrial applications as electro-plating, steelmaking, tanning of leather goods, and as corrosion inhibitors. The use of flat sheet supported liquid membranes (FSSLMs) to remove metals from wastewaters has been actively undertaken by both the scientific and industrial communities. The present work deals with carrier-facilitated membrane transport of Cr(VI) from acidic media across a FSSLM using the organic extractant reagent Alamine 336. The efficiency of the membrane transport was optimized as a function of pH, diluent type, strip phase (NaOH) concentration, feed and strip phase mixing speed, extractant type and concentration, and support type. Various initial feed phase Cr(VI) concentrations were studied under the optimum conditions. At a 2,000 ppm optimum feed phase concentration, the FSSLM showed no significant loss in permeability and retained the same transport ability over 49 h. Under that condition, the extraction of Cr(VI) was found to be > 99% and the mass flux and permeation coefficient were calculated using related equations as 7.35 × 10−6 kg m−2 s and 7.88 × 10−6 m s−1, respectively.

Separation of Carrier Free 90Y from 90Sr by Hollow Fiber Supported Liquid Membrane Containing Bis(2-ethylhexyl) Phosphonic Acid

The present article gives a comparative account of the efficiency of carrier-free 90Y separation from 90Sr by solvent extraction, flat sheet-supported liquid membrane (FSSLM) and hollow fiber-supported liquid membrane (HFSLM) methods using bis(2-ethylhexyl) phosphonic acid (PC88A) as the carrier extractant. The major focus of this work has been to develop the HFSLM method for the separation of Y(III) on a relatively large scale. The feed and receiver phase conditions were optimized by carrying out batch solvent-extraction studies. The extraction of Sr(II) by PC88A was negligible in the acidity range of 0.01–3 M HNO3, whereas the extraction of Y(III) was significantly large at lower acidity (≤0.1 M HNO3) with a separation factor (SF = DY/DSr) of 8.5 × 104. HFSLM studies suggested selective and efficient transport of Y(III) into 3 M HNO3 from a feed solution containing a mixture of Y(III) and Sr(II) at 0.1 M HNO3. On the other hand, transport of Sr(II) was negligible in the receiver phase. The purity of the separated 90Y was ascertained by paper chromatography and by half-life measurement. The radiation stability of the carrier was excellent as studied up to 1000 KGy dose.