Polymer Inclusion Membranes Research Articles

An efficient cobalt separation using PVDF-co-HFP based ultrafiltration polymer inclusion membrane by room temperature ionic liquids

Cobalt has been used enormously in industrial and technological applications, especially lithium-ion batteries. Continuing production of cell phones and laptops containing lithium-ion batteries has increased demand for cobalt, which has resulted in a global accumulation of industrial waste in the world. As a result, the separation and purification of cobalt from industrial waste become quietly important. In this study, the high-efficiency recovery of cobalt ions was achieved by PVDF-co-HPF (polyvinylidene fluoride hexafluoropropylene) based ultrafiltration polymer inclusion membranes (UPIM), which were produced by mixing room temperature ionic liquids, plasticizers, and the polymer under optimal conditions. The highest mass transfer coefficient (Jo) of cobalt transport was determined as 3.36x10-6 mol/s m−2 for the optimized UPIM containing 11.35 % (w/w) ONPOE (2-nitrophenyl octyl ether) and 12.27 % (w/w) RTIL4 (1,3-decyl-1H-imidazol-3-ium bromide). Morphological and structural analysis of all UPIMs were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). A good relationship was determined between the cobalt peaks in the ATR-FTIR pattern and the color intensity of UPIMs with corresponding room temperature ionic liquids. It indicates that the optimized UPIM has a good potential not only for cobalt recovery but also for qualitative and quantitative direct colorimetric cobalt determination.

Transport of Zn (Ⅱ) through matrix enhanced polymer inclusion membrane containing OHA and D2EHPA

Recovery of heavy metal ions from waste water has benefits both in terms of resources reuse and environmental protection. Polymer inclusion membrane (PIM) has received increasing attention as a gentle and simple method compared to other separation techniques for the removal and recovery of heavy metal ions. The extractant and matrix are the most important components of the PIM. In this paper, a novel matrix enhanced polymer inclusion membrane (ME-PIM) system containing both octyl hydroxamic acid (OHA) and di (2-ethylhexyl) phosphoric acid (D2EHPA) as the carriers as well as poly(vinyl) chloride (PVC) and poly (vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) as the matrix was reported. The SEM results indicate that the PVC has excellent compatibility with OHA and D2EHPA, resulting in dense ME-PIM compared to PVDF-CTFE. The effects of OHA and D2EHPA with different carrier ratios on the transport and the stability of the membrane were examined using Zn (Ⅱ) as a representative of heavy metal ions. The optimal results of this work showed that the initial mass transfer flux value of Zn (Ⅱ) was as high as 4.73 μmol/(m2·s), corresponding to a permeability of 2.21 × 10−2 m/h, using the ME-PIM composed of 61 wt.% PVC and 22 wt.% OHA + 17 wt.% D2EHPA. All these results suggest that the ME-PIM has a much higher initial mass transfer flux than those of PIMs in literatures. The addition of OHA to PIM introduced extractive functional groups into the polymer chain, forming an efficient and progressive mass transfer path with the extractant D2EHPA. Utilizing two extractants with synergistic effects, this novel ME-PIM system provides a potential advantage in promoting the mass transfer of metal ions in a PIM.

Extraction of Lithium from Brine with a High Mg/Li Ratio Using Polymer Inclusion Membrane Containing Tri-n-butyl Phosphate and Ionic Liquid

Extraction of Lithium from Brine with a High Mg/Li Ratio Using Polymer Inclusion Membrane Containing Tri-n-butyl Phosphate and Ionic Liquid

Efficient and Original Technique for the Optimization and Intensification of Membrane Processes Relating to the Treatment and Recovery of Discharges Loaded with the Emerging Pollutant Paracetamol

Paracetamol (acetaminophen) is one of the most commonly used pain relievers and fever reducers due to the high stability, solubility, and hydrophilicity; it is mainly detected in pharmaceutical releases. Its presence in aquatic systems is a serious ecological concern. The pharmaceutical industries are using several technologies for separation, extraction, and control such as membrane processes because of their numerous advantages. In the present work, a polymer inclusion membrane containing Tween 20 (TW20) as an extractive agent was fabricated for the treatment and recovery of effluents loaded with emerging pollutants (paracetamol). After characterization of the morphology and porosity, the membrane was adopted to carry out the extraction and recovery processes of paracetamol, assisted by activated carbon. Kinetic and thermodynamic models were applied to determine the values of permeability (P), initial flux (J0), association constant (Kass), and diffusion apparent coefficient (D*) parameters. Subsequently, activation parameters energy (Ea), association and dissociation enthalpies (ΔH#ass and ΔH#dis, respectively), and entropy (ΔS#) were measured. For this original technique, the effects of activated carbon on the evolution of processes carried out across the membrane have been investigated and indicate a significant optimization and intensification of the membrane performance and total paracetamol extraction rate. In addition, this technique is clean and does not affect the structure or the stability of the membrane.

Polymer Inclusion Membranes with P507-TBP Carriers for Lithium Extraction from Brines.

The separation of lithium and magnesium from salt-lake brines with high Mg2+/Li+ ratios is a main challenge for lithium extraction. In this work, novel polymer inclusion membranes (PIMs) were developed by incorporating 2-ethylhexyl phosphonic acid mono 2-ethylhexyl (P507) and tributyl phosphate (TBP) as the carriers into cellulose triacetate (CTA) polymers. The Li+ could be stripped from the P507-TBP extracting carriers using pure water eluents without adding concentrated hydrochloric acid, which can help decrease carriers’ leakage risk from membrane matrixes and keep the stability of PIMs. The morphology, composition, and wettability of P507-TBP-based PIMs were characterized systematically, and the carrier content in the PIM was also optimized. In the transport experiment with the feed of 0.1 mol/L LiCl and 4.0 mol/L MgCl2, the CTA/P507-TBP60% membrane exhibits a Li+ permeability of 4.76 × 10−3 mol·m−2·h−1 and a Li/Mg separation ratio of 10.2. After recycling seven times, the selectivity of the PIM is well-retained (>10), and the permeability of Li+ decreases slightly (less than 15%). With a decent selectivity and excellent stability, PIMs containing P507-TBP carriers show great potential for sustainable and efficient lithium recovery from brines with high Mg/Li ratios.

Optimisation of ciprofloxacin removal by using polymer inclusion membrane and its multivariate analysis with half‐fractional factorial design

AbstractBACKGROUNDIn this study, the use of polymer inclusion membranes (PIMs) to attenuate the recalcitrant contaminant of ciprofloxacin (CIP) in an aquatic system is presented. Poly(vinyl)chloride (PVC) was used as the base polymer, bis−2‐(Ethylhexyl) phosphate (B2EHP) as the carrier, and dioctyl phthalate (DOP) as the plasticizer. Optimisation of the experiment was conducted using multivariate analysis of half‐fractional factorial design, focusing on parameters like pH of the source solution, the source solution's concentration, carrier composition, the concentration of the receiving solution, and extraction time.RESULTSIt was found that PIMs with the composition of PVC 45%: B2EHP 25%: DOP 30% were the best suited for this purpose. The optimal removal efficiency of CIP was ˃99% at pH 6, 90% at pH 12, and 85% removal at neutral pH (7). After various optimisation steps, the method was applied to actual environmental wastewater and river samples with an average percentage removal efficiency of ˃97%.CONCLUSIONThis study has successfully demonstrated the feasibility of using PIMs for the removal of CIP antibiotics. Hence, it may be considered a practical treatment approach for other pharmaceutical residues in the aquatic system. © 2022 Society of Chemical Industry (SCI).

Separation of Co from Ni and Li from chloride media using polymer inclusion membrane system with thiosalicylate based ionic liquid

Separation of Co from Ni and Li from chloride media using polymer inclusion membrane system with thiosalicylate based ionic liquid

Use of Polymer Inclusion Membrane for the Separation of Phenols Compounds Mixture from Dilute Aqueous Solutions

Abstract: Separation of phenolic compounds mixture namely: phenol, resorcinol, Bisphenol A from dilute aqueous solutions by polymer inclusion membrane using Cellulose triacetate (CTA) as support was investigated as a means of recovering Bisphenol A from mixture of phenolic compounds. The effects of parameters influencing the separation performance were studied in terms of permeation flux and selectivity. For competitive transport of phenols across PIM with RC8 + NPOE, the selectivity order was Bisphenol > Phenol > Resorcinol. The high permselectivity of the membrane to Bisphenol A was primarily due to its high affinity towards calixresorcinarene macrocycle. This is of particular interest from an industrial point of view because the enriched phenol permeate can be easily recovered upon phase separation. The prepared PIM were characterized by using Raman spectroscopy, XPS and scanning electron microscopy (SEM) techniques.
 Keywords: PIM, CTA, Membrane separation, Phenols mixture, Bisphenol A, Wastewater treatment.

Optimisation of semi-upscaled polymer inclusion membrane (PIMs) based device for passive remediation of metal ions in acid mine drainage (AMD)

Acid mine drainage (AMD) has been a source of environmental contamination in many parts of the world. This is because many countries depend on mining as a source of revenue. However, waste tailing dumps often leach out toxic waste with high levels of metal ions and flow downstream to dams and rivers. The current remediation methods (passive and active) are expensive or ineffective for long-term use. In some cases, these methods generate solid slag waste as a major by-product. However, as part of the green and circular economy, waste materials are viewed as potential resources for raw materials. This work then reports on the design, laboratory optimisation and early-stage application of semi-pilot passive remediation device for the possible recovery of metal ions (cadmium, cobalt, copper, iron, and nickel) in AMD generated in the tailings pond. The sampling remediation device consisted of a polymer inclusion membrane composed of polyvinyl chloride and di-(2-ethylhexyl) phosphoric acid as a semi-penetrable barrier. The device had an upscaled chamber made of nylon with 1000 mL of the receiving solution. This developed passive remediation device was used in both synthetic and real AMD samples where a linear uptake of metals was demonstrated from day 6 to over a month with little influence of matrices. During deployment, the pH was increasing in the receiving solution and decreasing in the source solution of the linear region thus indicating the analytes facilitated transport. On day 35 of environmental application accumulated concentrations of target metal ions were Ni (63.42 mg L−1), Cd (47.48 mg L−1), Co (57.34 mg L−1), and Cu (49.86 mg L−1). Further, the characterisation results showed no signs of membrane degradation in this period. This highlights that the PIMs are a promising future for passive remediation and/or recovery of metal ions in mine wastewater before contamination of rivers and dams downstream.

A novel approach in the removal of ciprofloxacin antibiotic in an aquatic system using polymer inclusion membrane

Ciprofloxacin (CIP) in the aquatic environment has been widely studied due to its ability to be persistent in the environment. Residues of this contaminant are ubiquitous in different environmental media due to the inability of conventional wastewater treatment plants (WWTPs) to remove them completely. Various advanced wastewater treatments have been used to attenuate this contaminant; however, it remained refractory in the environment. In this study, we investigated the removal of ciprofloxacin using poly(vinyl)chloride (PVC) and cellulose triacetate (CTA) based polymer inclusion membranes (PIMs). Different parameters were investigated, such as the effect of the types of carriers (Bis-2-(ethylhexyl) phosphate (B2EHP) and tricapryl-methylammonium chloride (Aliquat 336), pH, initial concentration of feed solution, and concentration of the stripping solution. The produced PIM was chemically and mechanically stable. At optimum conditions, the removal efficiency of 99.2%, transport efficiency of 70%, and a permeability coefficient of 20.1 μ m/s were recorded using PVC/B2EHP membrane, whilst a removal efficiency of 95% was recorded using CTA/B2EHP membrane. However, using Aliquat 336 as the carrier, the highest removal efficiency of 60% was recorded. Finally, the PIM was used to remediate CIP in real environmental samples (river water and wastewater). From an initial concentration of 200 ng/L, it was reduced to 1.8 ng/L in river water and 2.2 ng/L in wastewater which is 99.1% and 98.9 % removal, respectively. Thus, PIM could be considered a suitable alternative for the removal of CIP in the aquatic environment. • Removal of CIP using polymer inclusion membranes (PIMs) was demonstrated. • Effects of different carriers, pH, feed and stripping solutions were investigated. • The removal efficiencies of the prepared PIMs are within 60%–99%. • The PIMs were used to remediate CIP in real samples, 98%–99% removals were achieved. • It may be used for the removal other recalcitrant antibiotics such as levofloxacin.

Stability study of polymer inclusion membranes (PIMs) based on acidic (D2EHPA), basic (Aliquat 336) and neutral (TOPO) carriers: effect of membrane composition and aqueous solution

Stability study of polymer inclusion membranes (PIMs) based on acidic (D2EHPA), basic (Aliquat 336) and neutral (TOPO) carriers: effect of membrane composition and aqueous solution

Recovery of scandium from acidic waste solutions by means of polymer inclusion membranes

Scandium is a raw material with properties that promise considerable potential for application in alloys to enable aviation fuel savings and as dopants for use in sustainable energy production using solid oxide fuel cells. Despite these attractive properties, scandium is rarely used due to its scarcity and unreliable supply. Therefore, new strategies for scandium recovery are of economic priority. In this study, polymer inclusion membranes (PIMs) consisting of PVDF-HFP, 2-NPOE and DEHPA, were optimised for selective scandium separation from real TiO2 production waste. With the optimised system, >60% of the scandium was recovered with high selectivity, resulting in scandium mole fraction at more than two orders of magnitude higher in the receiving phase than in the original waste. This suggests PIMs may be an effective way to recover scandium from bulk waste, thus easing the scarcity and insecurity that currently limit its bulk application.

Vanadium recovery by electrodialysis using polymer inclusion membranes

Industrial applications and environmental awareness recently prompted vanadium recovery spell from secondary resources. In this work, a polymer inclusion membrane containing trioctylmethylammonium chloride as carrier was successfully employed in electrodialysis for vanadium recovery from acidic sulfate solutions. The permeability coefficient of V(V) increased from 0.29 µm·s-1 (without electric field) to 4.10 µm·s-1 (with the 20 mA·cm-2 current density). The transport performance of VO2SO4-, which was the predominant species containing V(V) in the acidic region (pH <3), was influenced by the aqueous pH value and sulfate concentration. Under an electric field, a low concentrated H2SO4 solution (0.2 M) effectively stripped V(V) from the membranes, avoiding the requirement of a highly concentrated H2SO4 without electric field. Under the optimum conditions, the permeability coefficient and flux reached 6.80 µm·s-1 and 13.34 µmol·m-2·s-1, respectively. High selectivity was observed for the separation of V(V) and Mo(VI) from mixed solutions of Co (II), Ni (II), Mn (II), and Al (III). Additionally, the separation between Mo(VI) and V(V) was further improved by adjusting the acidity of the stripping solution. The V(V) selectivity for the resulting membrane was higher than that of commercial anion exchange membranes.

Competitive Transport of Metal Ions through a PVDF-CTA Based Polymer Inclusion Membrane Containing D2EHPA As Carrier

Competitive Transport of Metal Ions through a PVDF-CTA Based Polymer Inclusion Membrane Containing D2EHPA As Carrier

PVC/EVA-based polymer inclusion membranes with improved stability and Cr(VI) extraction capacity: Water plasticization effect

Polymer inclusion membranes (PIMs) are far investigated for their ability to extract heavy metals and small organic compounds from aqueous media. Polyvinyl chloride (PVC) is one of the most widely used base polymers for the PIM elaboration. However, its use requires the incorporation of a relatively expensive liquid plasticizer. In the present work, poly(ethylene-co-vinyl acetate) (EVA) serves as a polymer plasticizer for the elaboration of PIMs based on PVC as a base polymer and Aliquat 336 as a carrier. The composition of PIMs was optimized in terms of the PVC/EVA ratio and the vinyl acetate (VA) groups content (x) of EVA (i.e. EVAx). Physical-chemical properties of the resulting membranes are analyzed and correlated with their structure. The results of SEM analysis revealed miscible PVC/EVA70 blends (i.e. with 70 wt% of VA groups) and partially miscible PVC/EVA40 blends. The plasticizing effect of the EVA copolymer was confirmed by the tensile test results. The results of transport measurements showed that PIMs containing EVA40 and PVC are more efficient for the Cr(VI) extraction than those with only PVC. Thus, EVA40 can effectively replace the conventional liquid plasticizers while improving the Cr(VI) permeability. Besides, it is stated that EVA40-based PIMs are more stable as compared with conventional PIMs due to the water plasticizing effect. After the membrane optimization, the highest Cr(VI) transport flux (54.7 µmol·m-2·s-1) was measured. Moreover, the addition of 10 wt% of tetradecanol causes the increase of the water plasticizing effect and allows obtaining a PIM with high stability (up to 24 cycles) required for the membrane long-term operation.

Separation of Mercury(II) from Industrial Wastewater through Polymer Inclusion Membranes with Calix[4]pyrrole Derivative.

Polymer membranes with immobilized ligands are encouraging alternatives for the removal of toxic metal ions from aquatic waste streams, including industrial wastewater, in view of their high selectivity, stability, removal efficacy and low energy demands. In this study, polymer inclusion membranes (PIMs) based on cellulose triacetate, with a calix[4]pyrrole derivative as an ion carrier, were tested for their capability to dispose mercury (Hg(II)) ions from industrial wastewater. The impacts were assessed relative to carrier content, the quantity of plasticizer in the membrane, the hydrocholoric acid concentration in the source phase, and the character of the receiving phase on the performance of Hg(II) elimination. Optimally designed PIMs could be an interesting option for the industrial wastewater treatment due to the high removal efficiency of Hg(II) and great repeatability.

Membrane extraction of V(V) by an oleic acid plasticized poly(vinyl chloride)/Aliquat® 336 polymer inclusion membrane

AbstractPolymer inclusion membranes (PIMs) have received much attention as a greener method than other liquid membranes for the separation of a great number of chemical species. The expected horizon of industrial applications besides the advantages of greener characteristics of PIMs than other liquid membranes and solvent extraction methods, have resulted in development of the new PIMs for specific tasks. In the presented study, a PIM composed of polyvinyl chloride, Aliquat® 336, and oleic acid (50/40/10 wt%, respectively) is fabricated and its characteristics are studied. Membrane segments (3.5 cm diameter, 0.110 ± 0.013 g) can extract 73% of V(V) (initial concentration 50 mg L−1) from 50 ml Na2SO4 solution (0.1 M) adjusted to pH 2.5 after 8 h shaking. The extraction is proceeded by an anion exchange mechanism in which chloride anion of the extractant is replaced by VO2SO4−. It is approved that ~97% of the extracted amount of V(V) is back‐extracted from the loaded PIMs by contacting them, for 24 h, with 50 ml 7 mol L−1 H2SO4/0.25 v/v% of H2O2. The PIM extracts selectively V(V) from the simulated solutions like that obtained by digestion of spent alumina hydrodesulfurization catalysts.

Modelling and optimization of a new complexing retardant-enhanced polymer inclusion membrane system for highly selective separation of Zn2+ and Cu2+

Polymer inclusion membranes (PIMs) have much application potential for metal ion separation. However, its separation selectivity highly depends on the extractant, and new efficient extractants are difficult to develop. This work proposes another approach, i.e., adding a complexing retardant to enhance the selectivity. The impurity ion (e.g., Cu2+) was retarded in the feed solution by the complexing retardant (e.g., citric acid), while the target ion (e.g., Zn2+) was transported across PIM. To reveal the enhancement mechanism, a mass transfer mathematical model was established. Contrast experiments proved that the complexing retardant can significantly enhance the overall separation coefficient βoverall,exp. The βoverall,exp of a conventional PIM system was 61.80, while βoverall,exp increased to 853.45 after the retardant was added. The effects of retardant concentration, initial pH of feed solution, membrane thickness, extractant dosage, and plasticizer dosage on the retardant-enhanced PIM system were investigated. Model calculation results agreed well with the experimental data. The maximal βoverall,exp 17525.68 was obtained at the optimal separation conditions of [CA] f,0 = 0.02 M, pHf,0 = 4.5, [H2SO4]s,0 = 0.5 M, and the optimal composition of the PIM casting solution, i.e., PVC: P507: DBP: THF = 0.125 g: 0.188 mL: 0.032 mL: 10 mL. Further studies indicated that the retardant mechanism was reflected in the difference increase of interfacial partition coefficients PZn2+,f and PCu2+,f. Finally, the optimization strategies of the separation effects for the retardant-enhanced PIM system are discussed in depth based on the simulated calculation.

Removal of methylene blue dye from aqueous solutions using polymer inclusion membrane technology

The polymer inclusion membranes (PIMs) containing Cellulose triacetate as polymer base, 2-NPOE as a plasticizer, and Calix[4]resorcinarene (RC8) as a carrier were prepared and characterized. Microstructure and surface of PIMs were characterized by scanning electron microscope, FTIR, UV/vis spectroscopy, and Thermogravimetric Analysis, respectively. In order to obtain information on the composition and interactions that may manifest between the constituents of the membrane. The PIMs were applied in the elimination of Methylene Blue (MB) dye from model solution as synthetic aqueous wastewater. Furthermore, the effects of different parameters such as internal and external PIMs environment on the transport performance of MB were also investigated. The results confirming that the content of the carrier and plasticizer in the membrane had a significant impact on the property of PIMs. The transport of dye was in line with the first-order kinetics equation. The highest flux value "8.88 × 10–7 mol.m−2 s−1" was obtained with a calix [4] resorcinarene as a transporter in polymer inclusion membrane at pH 11 in the feed and 0.3 M HCl in the stripping phase when MB initial concentration was 100 mg/L. The membrane has better stability under optimum conditions and maximum transport was observed after 30 h of permeation time.

Fabrication of a novel polymer inclusion membrane from recycled polyvinyl chloride for the real-time extraction of arsenic (V) from water samples in a continuous process

In this work, the integration of recycled polyvinyl chloride (PVC) material as a base polymer and benzalkonium chloride (BAC) as an extractant to develop low-cost Polymer Inclusion Membranes (PIM) for the extraction of Arsenic (V) from water. Notably, the production of 1 m2 of PIM may cost approximately 0.0016$. It was found that 10% of recycled PVC can be easily substituted with the base polymer without much efficiency variation. The extraction efficiency of As(V) for PVC/BAC/Dioctyl phthalate (DOP) and PVC+recycled PVC (RPVC)/BAC/DOP membranes were around only 57.8 ± 1% and 56.2 ± 1%, respectively. To overcome such a less efficient barrier, we have designed a device that increased the final extraction capability of 100 mgL-1 concentration of As(V) to ~91 ± 1% over 100 h working at the consistent operating conditions be used for wastewater treatment-based industries. Thus, the developed PIM membrane permits the transport of As(V) at higher concentrations for different natural waters spiked with 100 ppm As(V). Herein, we did not observe any matrix effect on As(V) transport efficiency with different waters except seawater, which contains a high level of ions. Furthermore, the effect of biofilm growth on the surface of PIMs has been inspected for a period of beyond 10 days. Therefore, the novel low-cost PIM device can be used in metal and alloy-based industries to extract As(V) from contaminated wastewater efficiently.