1
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Espinoza C, Díaz JC, Kitto D, Kim HK, Kamcev J. Bound Water Enhances the Ion Selectivity of Highly Charged Polymer Membranes. ACS APPLIED MATERIALS & INTERFACES 2024; 16:45433-45446. [PMID: 39136307 DOI: 10.1021/acsami.4c07516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Electrochemical technologies for water treatment, resource recovery, energy generation, and energy storage rely on charged polymer membranes to selectively transport ions. With the rise of applications involving hypersaline brines, such as management of desalination brine or the recovery of ions from brines, there is an urgent need for membranes that can sustain high conductivity and selectivity under such challenging conditions. Current membranes are constrained by an inherent trade-off between conductivity and selectivity, alongside concerns regarding their high costs. Moreover, a gap in the fundamental understanding of ion transport within charged membranes at high salinities prevents the development of membranes that could meet these stringent requirements efficiently. Here, we present the synthesis of scalable, highly charged membranes that demonstrate high conductivity and selectivity while contacting 1 and 5 molal NaCl solutions. A detailed analysis of the membrane transport properties reveals that the high proportion of bound water in the membranes, enabled by the high charge content and hydrophilic structure of the polymers, enhances both the ion partitioning and diffusion selectivities of the membranes. These structure/property relationships derived from this study offer valuable guidance for designing next-generation membranes that simultaneously achieve exceptional conductivity and selectivity in high-salinity conditions.
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Affiliation(s)
- Carolina Espinoza
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex B28, 2800 Plymouth Rd., Ann Arbor 48109, Michigan, United States
| | - José C Díaz
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex B28, 2800 Plymouth Rd., Ann Arbor 48109, Michigan, United States
| | - David Kitto
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex B28, 2800 Plymouth Rd., Ann Arbor 48109, Michigan, United States
| | - Hyunjik K Kim
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex B28, 2800 Plymouth Rd., Ann Arbor 48109, Michigan, United States
| | - Jovan Kamcev
- Department of Chemical Engineering, University of Michigan, North Campus Research Complex B28, 2800 Plymouth Rd., Ann Arbor 48109, Michigan, United States
- Macromolecular Science and Engineering, University of Michigan, North Campus Research Complex B28, 2800 Plymouth Rd., Ann Arbor 48109, Michigan, United States
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2
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Kogler A, Sharma N, Tiburcio D, Gong M, Miller DM, Williams KS, Chen X, Tarpeh WA. Long-Term Robustness and Failure Mechanisms of Electrochemical Stripping for Wastewater Ammonia Recovery. ACS ENVIRONMENTAL AU 2024; 4:89-105. [PMID: 38525023 PMCID: PMC10958661 DOI: 10.1021/acsenvironau.3c00058] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/14/2023] [Accepted: 12/22/2023] [Indexed: 03/26/2024]
Abstract
Nitrogen in wastewater has negative environmental, human health, and economic impacts but can be recovered to reduce the costs and environmental impacts of wastewater treatment and chemical production. To recover ammonia/ammonium (total ammonia nitrogen, TAN) from urine, we operated electrochemical stripping (ECS) for over a month, achieving 83.4 ± 1.5% TAN removal and 73.0 ± 2.9% TAN recovery. With two reactors, we recovered sixteen 500-mL batches (8 L total) of ammonium sulfate (20.9 g/L TAN) approaching commercial fertilizer concentrations (28.4 g/L TAN) and often having >95% purity. While evaluating the operation and maintenance needs, we identified pH, full-cell voltage, product volume, and water flux into the product as informative process monitoring parameters that can be inexpensively and rapidly measured. Characterization of fouled cation exchange and omniphobic membranes informs cleaning and reactor modifications to reduce fouling with organics and calcium/magnesium salts. To evaluate the impact of urine collection and storage on ECS, we conducted experiments with urine at different levels of dilution with flush water, extents of divalent cation precipitation, and degrees of hydrolysis. ECS effectively treated urine under all conditions, but minimizing flush water and ensuring storage until complete hydrolysis would enable energy-efficient TAN recovery. Our experimental results and cost analysis motivate a multifaceted approach to improving ECS's technical and economic viability by extending component lifetimes, decreasing component costs, and reducing energy consumption through material, reactor, and process engineering. In summary, we demonstrated urine treatment as a foothold for electrochemical nutrient recovery from wastewater while supporting the applicability of ECS to seven other wastewaters with widely varying characteristics. Our findings will facilitate the scale-up and deployment of electrochemical nutrient recovery technologies, enabling a circular nitrogen economy that fosters sanitation provision, efficient chemical production, and water resource protection.
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Affiliation(s)
- Anna Kogler
- Department
of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Neha Sharma
- Stanford
Synchrotron Radiation Lightsource, SLAC
National Accelerator Laboratory, Menlo Park, California 94205, United States
- Department
of Chemical Engineering, Stanford University, 443 Via Ortega, Room 387, Stanford, California 94305, United States
| | - Diana Tiburcio
- Department
of Mechanical Engineering, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Meili Gong
- Department
of Chemical Engineering, Stanford University, 443 Via Ortega, Room 387, Stanford, California 94305, United States
| | - Dean M. Miller
- Department
of Chemical Engineering, Stanford University, 443 Via Ortega, Room 387, Stanford, California 94305, United States
| | - Kindle S. Williams
- Department
of Chemical Engineering, Stanford University, 443 Via Ortega, Room 387, Stanford, California 94305, United States
| | - Xi Chen
- Department
of Chemical Engineering, Stanford University, 443 Via Ortega, Room 387, Stanford, California 94305, United States
| | - William A. Tarpeh
- Department
of Chemical Engineering, Stanford University, 443 Via Ortega, Room 387, Stanford, California 94305, United States
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3
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Wu L, Jiang H, Luo T, Wang X. On the Ionic Conductivity of Cation Exchange Membranes in Mixed Sulfates Using the Two-Phase Model. MEMBRANES 2023; 13:811. [PMID: 37887983 PMCID: PMC10608779 DOI: 10.3390/membranes13100811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023]
Abstract
The concentration dependence of the conductivity of ion exchange membranes (IEMs), as well as other transport properties, has been well explained by the contemporary two-phase model (Zabolotsky et al., 1993) considering a gel phase and an inter-gel phase filled with electroneutral solution. Here, this two-phase model has been adopted and first applied in electrolytes containing mixed counter-ions to investigate the correlation between the membrane ionic conductivity and its microstructure. For three representative commercial cation exchange membranes (CEMs), the total membrane conductivity (κT) when in equilibrium with mixed MgSO4 + Na2SO4 and H2SO4 + Na2SO4 electrolytes could be well predicted with the experimental composition of counter-ions in the gel and inter-gel phase, as well as the counter-ion mobility in the gel phase when the membrane is in a single electrolyte. It is found that the volume fraction of the inter-gel phase (f2) has little impact on the predicted results. The accuracy of the model can be largely improved by calculating the inter-gel phase conductivity (κin) with the ionic mobility being the same as that in the external solution (obtained via simulation in the OLI Studio), rather than simply as equivalent to the conductivity of the external solution (κs). Moreover, a nonlinear correlation between the CEMs' conductivities and the counter-ion composition in the gel phase is observed in the mixed MgSO4 + Na2SO4 solution, as well as for the Nafion117 membrane in the presence of sulfuric acid. For CEMs in mixed MgSO4 + Na2SO4 electrolytes, the calculated conductivity values considering the interaction parameter σ, similar to the Kohlrausch's law, are closer to the experimental ones. Overall, this work provides new insights into membrane conductivity with mixed counter-ions and testifies to the applicability of the contemporary two-phase model.
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Affiliation(s)
| | | | - Tao Luo
- Ministry of Education’s Research Center for Comprehensive Utilization and Clean Process Engineering of Phosphorous Resources, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
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4
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Perveen S, Hussain SG, Ahmed MJ, Khawar R, Siraj TB, Saleem M. A Viable and sustainable flat- membrane plate-and-frame module for spent acid regeneration and metal ion recovery. Heliyon 2023; 9:e18344. [PMID: 37520977 PMCID: PMC10382638 DOI: 10.1016/j.heliyon.2023.e18344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/05/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023] Open
Abstract
This study provides techno-economical insights for acid regeneration and metal recovery from spent acidic wastewater by a diffusion dialysis plate-and-frame module using Quaternized Polyepichlorohydrin - Polyacrylonitrile (QPECH-PAN) membranes. Quaternized Polyepichlorohydrin (QPECH) membranes were synthesized using 1,4-diazobicyclo[2.2.2]octane (DABCO) and blended with polyacrylonitrile (PAN). Said membranes were analyzed in terms of their mechanical, physicochemical, and electrochemical characteristics, providing significant results comparable to the commercial membranes (IEC: 1.76 mmol/g, SD: 60.91%, Permselectivity: 79.5 ± 0.31%, and transport no. t(-): 0.5). Mechanical characterization reveals that the QPECH-PAN membranes possess comparable mechanical strengths (tensile strength: 329.56 MPa). Further, sheet resistivity (6.11 Ω cm2) and conductivity (0.16 S/cm2) reveal the relative conductive nature of these membranes. Percent acid recovery and metal ion recovery ratios were found to be 72% and 48% respectively, and separation factors were 126.8 and 84.57 respectively. The QPECH-PAN membrane's techno-economic feasibility was also analyzed within the context of a textile industry processing up to 5500 kg/d of acidic wastewater. It indicates a potential cost saving of US $0.53 million on H2SO4 and NaOH, as well as an OPEX saving of 40.91% against a semi-continuous acid neutralizer.
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Affiliation(s)
- Shazia Perveen
- Department of Chemistry, NED University of Engineering & Technology, University Road, Karachi 75270, Sindh, Pakistan
| | - Syed Ghazanfar Hussain
- Department of Chemistry, NED University of Engineering & Technology, University Road, Karachi 75270, Sindh, Pakistan
| | - Muzamil Jalil Ahmed
- Department of Chemistry, NED University of Engineering & Technology, University Road, Karachi 75270, Sindh, Pakistan
| | - Ruba Khawar
- Department of Chemistry, NED University of Engineering & Technology, University Road, Karachi 75270, Sindh, Pakistan
| | - Taha Bin Siraj
- Department of Chemistry, NED University of Engineering & Technology, University Road, Karachi 75270, Sindh, Pakistan
| | - Maryam Saleem
- Department of Chemistry, NED University of Engineering & Technology, University Road, Karachi 75270, Sindh, Pakistan
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Pismenskaya N, Rybalkina O, Solonchenko K, Butylskii D, Nikonenko V. Phosphates Transfer in Pristine and Modified CJMA-2 Membrane during Electrodialysis Processing of Na xH (3-x)PO 4 Solutions with pH from 4.5 to 9.9. MEMBRANES 2023; 13:647. [PMID: 37505013 PMCID: PMC10386648 DOI: 10.3390/membranes13070647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/27/2023] [Accepted: 07/03/2023] [Indexed: 07/29/2023]
Abstract
Phosphate recovery from different second streams using electrodialysis (ED) is a promising step to a nutrients circular economy. However, the relatively low ED performance hinders the widespread adoption of this environmentally sound method. The formation of "bonded species" between phosphates and the weakly basic fixed groups (primary and secondary amines) of the anion exchange membrane can be the cause of decrease in current efficiency and increase in energy consumption. ED processing of NaxH(3-x)PO4 alkaline solutions and the use of intense current modes promote the formation of a bipolar junction from negatively charged bound species and positively charged fixed groups. This phenomenon causes a change in the shape of current-voltage curves, increase in resistance, and an enhancement in proton generation during long-term operation of anion-exchange membrane with weakly basic fixed groups. Shielding of primary and secondary amines with a modifier containing quaternary ammonium bases significantly improves ED performance in the recovery of phosphates from NaxH(3-x)PO4 solution with pH 4.5. Indeed, in the limiting and underlimiting current modes, 40% of phosphates are recovered 1.3 times faster, and energy consumption is reduced by 1.9 times in the case of the modified membrane compared to the pristine one. Studies were performed using a new commercial anion exchange membrane CJMA-2.
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Affiliation(s)
- Natalia Pismenskaya
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Olesya Rybalkina
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Ksenia Solonchenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Dmitrii Butylskii
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Victor Nikonenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
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6
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Pismenskaya N, Rybalkina O, Solonchenko K, Pasechnaya E, Sarapulova V, Wang Y, Jiang C, Xu T, Nikonenko V. How Chemical Nature of Fixed Groups of Anion-Exchange Membranes Affects the Performance of Electrodialysis of Phosphate-Containing Solutions? Polymers (Basel) 2023; 15:polym15102288. [PMID: 37242863 DOI: 10.3390/polym15102288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/03/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Innovative ion exchange membranes have become commercially available in recent years. However, information about their structural and transport characteristics is often extremely insufficient. To address this issue, homogeneous anion exchange membranes with the trade names ASE, CJMA-3 and CJMA-6 have been investigated in NaxH(3-x)PO4 solutions with pH 4.4 ± 0.1, 6.6 and 10.0 ± 0.2, as well as NaCl solutions with pH 5.5 ± 0.1. Using IR spectroscopy and processing the concentration dependences of the electrical conductivity of these membranes in NaCl solutions, it was shown that ASE has a highly cross-linked aromatic matrix and mainly contains quaternary ammonium groups. Other membranes have a less cross-linked aliphatic matrix based on polyvinylidene fluoride (CJMA-3) or polyolefin (CJMA-6) and contain quaternary amines (CJMA-3) or a mixture of strongly basic (quaternary) and weakly basic (secondary) amines (CJMA-6). As expected, in dilute solutions of NaCl, the conductivity of membranes increases with an increase in their ion-exchange capacity: CJMA-6 < CJMA-3 << ASE. Weakly basic amines appear to form bound species with proton-containing phosphoric acid anions. This phenomenon causes a decrease in the electrical conductivity of CJMA-6 membranes compared to other studied membranes in phosphate-containing solutions. In addition, the formation of the neutral and negatively charged bound species suppresses the generation of protons by the "acid dissociation" mechanism. Moreover, when the membrane is operated in overlimiting current modes and/or in alkaline solutions, a bipolar junction is formed at the CJMA- 6/depleted solution interface. The CJMA-6 current-voltage curve becomes similar to the well-known curves for bipolar membranes, and water splitting intensifies in underlimiting and overlimiting modes. As a result, energy consumption for electrodialysis recovery of phosphates from aqueous solutions almost doubles when using the CJMA-6 membrane compared to the CJMA-3 membrane.
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Affiliation(s)
- Natalia Pismenskaya
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Olesya Rybalkina
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Ksenia Solonchenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Evgeniia Pasechnaya
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Veronika Sarapulova
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
| | - Yaoming Wang
- Anhui Provincial Engineering Laboratory of Functional Membrane Science and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Chenxiao Jiang
- Anhui Provincial Engineering Laboratory of Functional Membrane Science and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Tongwen Xu
- Anhui Provincial Engineering Laboratory of Functional Membrane Science and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Victor Nikonenko
- Russian Federation, Kuban State University, 149, Stavropolskaya Str., 350040 Krasnodar, Russia
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7
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Díaz JC, Kitto D, Kamcev J. Accurately measuring the ionic conductivity of membranes via the direct contact method. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.121304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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8
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Interfacial interactions between polymers and selective adsorbents influence ion transport properties of boron scavenging ion-exchange membranes. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.121301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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9
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Eti M, Cihanoğlu A, Güler E, Gomez-Coma L, Altıok E, Arda M, Ortiz I, Kabay N. Further Development of Polyepichlorohydrin Based Anion Exchange Membranes for Reverse Electrodialysis by Tuning Cast Solution Properties. MEMBRANES 2022; 12:membranes12121192. [PMID: 36557099 PMCID: PMC9786065 DOI: 10.3390/membranes12121192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/19/2022] [Accepted: 11/22/2022] [Indexed: 06/01/2023]
Abstract
Recently, there have been several studies done regarding anion exchange membranes (AEMs) based on polyepichlorohydrin (PECH), an attractive polymer enabling safe membrane fabrication due to its inherent chloromethyl groups. However, there are still undiscovered properties of these membranes emerging from different compositions of cast solutions. Thus, it is vital to explore new membrane properties for sustainable energy generation by reverse electrodialysis (RED). In this study, the cast solution composition was easily tuned by varying the ratio of active polymer (i.e., blend ratio) and quaternary agent (i.e., excess diamine ratio) in the range of 1.07-2.00, and 1.00-4.00, respectively. The membrane synthesized with excess diamine ratio of 4.00 and blend ratio of 1.07 provided the best results in terms of ion exchange capacity, 3.47 mmol/g, with satisfactory conductive properties (area resistance: 2.4 Ω·cm2, electrical conductivity: 6.44 mS/cm) and high hydrophilicity. RED tests were performed by AEMs coupled with the commercially available Neosepta CMX cation exchange membrane (CEMs).
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Affiliation(s)
- Mine Eti
- Department of Chemical Engineering, Faculty of Engineering, Ege University, 35100 İzmir, Turkey
| | - Aydın Cihanoğlu
- Department of Chemical Engineering, Faculty of Engineering, Ege University, 35100 İzmir, Turkey
| | - Enver Güler
- Department of Chemical Engineering, Atılım University, 06830 Ankara, Turkey
| | - Lucia Gomez-Coma
- Department of Chemical and Biomolecular Engineering, Universidad de Cantabria, Av. Los Castros 46, 39005 Santander, Spain
| | - Esra Altıok
- Department of Chemical Engineering, Faculty of Engineering, Ege University, 35100 İzmir, Turkey
| | - Müşerref Arda
- Department of Chemistry, Faculty of Science, Ege University, 35100 İzmir, Turkey
| | - Inmaculada Ortiz
- Department of Chemical and Biomolecular Engineering, Universidad de Cantabria, Av. Los Castros 46, 39005 Santander, Spain
| | - Nalan Kabay
- Department of Chemical Engineering, Faculty of Engineering, Ege University, 35100 İzmir, Turkey
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10
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Koók L, Rosa LF, Harnisch F, Žitka J, Otmar M, Nemestóthy N, Bakonyi P, Kretzschmar J. Functional stability of novel homogeneous and heterogeneous cation exchange membranes for abiotic and microbial electrochemical technologies. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.120705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Kim N, Jeong S, Go W, Kim Y. A Na + ion-selective desalination system utilizing a NASICON ceramic membrane. WATER RESEARCH 2022; 215:118250. [PMID: 35278915 DOI: 10.1016/j.watres.2022.118250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/27/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Seawater is a virtually unlimited source of minerals and water. Hence, electrodialysis (ED) is an attractive route for selective seawater desalination due to the selectivity of its ion exchange membrane (IEM) toward the target ion. However, a solution-like IEM, which is permeable to water and ions other than the target ion, results in the leakage of water as well as extraction of unwanted ions. This degrades the productivity and purity of the system. In this study, A novel desalination system was developed by replacing the cation exchange membrane (CEM) with a Na super ionic conductor (NASICON) in ED. NASICON exceptionally permits Na+ ion migration, and this enhanced the productivity of desalted water by removing 98% of Na+ while retaining water and other cationic minerals. Therefore, the final volume of desalted water in N-ED was 1.36 times larger compared to that of ED. In addition, the specific energy consumption for salt (NaCl) extraction was reduced by ∼13%. Furthermore, the NASICON in N-ED was replaced into a two-sided NASICON-structured rechargeable seawater battery, thereby further conserving ∼20% energy by simultaneously coupling selective desalination with energy storage. Our findings have positive implications and further optimizations of the NASICON will enable practical and energy-effective applications for seawater utilization.
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Affiliation(s)
- Namhyeok Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea
| | - Seongwoo Jeong
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea
| | - Wooseok Go
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea
| | - Youngsik Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea; R&D Center, 4TOONE Corporation, UNIST-gil 50, Ulsan 44919, Republic of Korea.
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12
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Study of the Electrical Conductivity of Ion-Exchange Resins and Membranes in Equilibrium Solutions of Inorganic Electrolytes. MEMBRANES 2022; 12:membranes12020243. [PMID: 35207164 PMCID: PMC8880273 DOI: 10.3390/membranes12020243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/03/2022] [Accepted: 02/05/2022] [Indexed: 02/04/2023]
Abstract
The study of the electrical conductivity of ion-exchange membranes in equilibrium electrolyte solutions is of great importance for the theory of membrane processes, in particular for practical electrodialysis. The purpose of the work is to determine the electrical conductivity of industrial ion-exchange membranes MK-40 and MA-40, as well as their basis—granules of a bulk layer of industrial ion exchangers KU-2-8 and EDE-10p, by differential and modified contact methods in electrolyte solutions and the development of a new methodology that will give the values that are closest to the true ones; determination of the dependence of electrical membrane conductivity depending on the type of counterion and concentration equilibrium solution and granules of a bulk layer of ion exchangers on the volume fraction of a dry ion exchanger with different degrees of compaction. It is shown that the dependence of the electrical conductivity of diaphragms on the electrolyte concentration, according to theoretical ideas, disappears under compression. It has been experimentally established that the difference method gives lower values of electrical conductivity in the region of low concentrations. The data obtained by the contact method are in good agreement with the results obtained for compressed diaphragms. The membrane conductivity decreases with increasing ion size.
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13
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Luin U, Valant M. Electrolysis energy efficiency of highly concentrated FeCl2 solutions for power-to-solid energy storage technology. J Solid State Electrochem 2022. [DOI: 10.1007/s10008-022-05132-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractAn electrochemical cycle for the grid energy storage in the redox potential of Fe involves the electrolysis of a highly concentrated aqueous FeCl2 solution yielding solid iron deposits. For the high overall energy efficiency of the cycle, it is crucial to maximize the energy efficiency of the electrolysis process. Here we present a study of the influence of electrolysis parameters on the energy efficiency of such electrolysis, performed in an industrial-type electrolyzer. We studied the conductivity of the FeCl2 solution as a function of concentration and temperature and correlated it with the electrolysis energy efficiency. The deviation from the correlation indicated an important contribution from the conductivity of the ion-exchange membrane. Another important studied parameter was the applied current density. We quantitatively showed how the contribution of the resistance polarization increases with the current density, causing a decrease in overall energy efficiency. The highest energy efficiency of 89 ± 3% was achieved using 2.5 mol L−1 FeCl2 solution at 70 °C and a current density of 0.1 kA m−2. In terms of the energy input per Fe mass, this means 1.88 Wh g−1. The limiting energy input per mass of the Fe deposit was found to be 1.76 Wh g−1.
Graphical abstract
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14
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Luin U, Arčon I, Valant M. Structure and Population of Complex Ionic Species in FeCl 2 Aqueous Solution by X-ray Absorption Spectroscopy. Molecules 2022; 27:642. [PMID: 35163907 PMCID: PMC8839570 DOI: 10.3390/molecules27030642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 11/16/2022] Open
Abstract
Technologies for mass production require cheap and abundant materials such as ferrous chloride (FeCl2). The literature survey shows the lack of experimental studies to validate theoretical conclusions related to the population of ionic Fe-species in the aqueous FeCl2 solution. Here, we present an in situ X-ray absorption study of the structure of the ionic species in the FeCl2 aqueous solution at different concentrations (1-4 molL-1) and temperatures (25-80 °C). We found that at low temperature and low FeCl2 concentration, the octahedral first coordination sphere around Fe is occupied by one Cl ion at a distance of 2.33 (±0.02) Å and five water molecules at a distance of 2.095 (±0.005) Å. The structure of the ionic complex gradually changes with an increase in temperature and/or concentration. The apical water molecule is substituted by a chlorine ion to yield a neutral Fe[Cl2(H2O)4]0. The observed substitutional mechanism is facilitated by the presence of the intramolecular hydrogen bonds as well as entropic reasons. The transition from the single charged Fe[Cl(H2O)5]+ to the neutral Fe[Cl2(H2O)4]0 causes a significant drop in the solution conductivity, which well correlates with the existing conductivity models.
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Affiliation(s)
- Uroš Luin
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, SI-5001 Nova Gorica, Slovenia; (U.L.); (I.A.)
| | - Iztok Arčon
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, SI-5001 Nova Gorica, Slovenia; (U.L.); (I.A.)
- Department of Low and Medium Energy Physics, J. Stefan Institute, Jamova 39, SI-1001 Ljubljana, Slovenia
| | - Matjaz Valant
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, SI-5001 Nova Gorica, Slovenia; (U.L.); (I.A.)
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15
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Filippov AN, Kononenko NA, Loza NV, Petrova DA. Modeling Asymmetry of a Current-Voltage Curve of a Novel MF-4SC/PTMSP Bilayer Membrane. MEMBRANES 2021; 12:membranes12010022. [PMID: 35054549 PMCID: PMC8779019 DOI: 10.3390/membranes12010022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/11/2021] [Accepted: 12/21/2021] [Indexed: 11/16/2022]
Abstract
A novel bilayer cation-exchange membrane—consisting of a thick layer of a pristine perfluorinated membrane MF-4SC (Russian equivalent of Nafion®-117) and a thinner layer (1 μm) of the membrane, on a base of glassy polymer of internal microporosity poly(1-trimethylsilyl-1-propyne) (PTMSP)—was prepared and characterized. Using the physicochemical characteristics of one-layer membranes MF-4SC and PTMSP in 0.05 M HCl and NaCl solutions, the asymmetric current–voltage curves (CVC) of the bilayer composite were described with good accuracy up to the overlimiting regime, based on the “fine-porous membrane” model. The MF-4SC/PTMSP bilayer composite has a significant asymmetry of CVC that is promising for using it in electromembrane devices, such as membrane detectors, sensors, and diodes.
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Affiliation(s)
- Anatoly N. Filippov
- Department of Higher Mathematics, National University of Oil and Gas Gubkin University, 119991 Moscow, Russia; (N.A.K.); (D.A.P.)
- Correspondence:
| | - Natalia A. Kononenko
- Department of Higher Mathematics, National University of Oil and Gas Gubkin University, 119991 Moscow, Russia; (N.A.K.); (D.A.P.)
- Department of Physical Chemistry, Kuban State University, 350040 Krasnodar, Russia;
| | - Natalia V. Loza
- Department of Physical Chemistry, Kuban State University, 350040 Krasnodar, Russia;
| | - Daria A. Petrova
- Department of Higher Mathematics, National University of Oil and Gas Gubkin University, 119991 Moscow, Russia; (N.A.K.); (D.A.P.)
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
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16
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Kamcev J. Reformulating the
permselectivity‐conductivity
tradeoff relation in
ion‐exchange
membranes. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20210304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Jovan Kamcev
- Department of Chemical Engineering, Macromolecular Science and Engineering University of Michigan, North Campus Research Complex Ann Arbor Michigan USA
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