Optimal multistage air gap membrane distillation (AGMD) for enhanced lithium extraction from medium- and low-quality brines.

Enhanced reduction of nitrate and synchronized transfer of ammonia by an integrated electrodialysis process

Scale-up and performance evaluation of an electrodialysis process in a municipal wastewater treatment plant

ABSTRACT The U.S. Department of Energy (DOE) national laboratories represent a unique class of government‐owned, contractor‐operated research institutions dedicated to conducting research and development (R&D) related activities that address national priorities, supporting and advancing the DOE mission. They play a vital role in sustaining U.S. innovation capacity, stewarding the nation's technical base, and nurturing science and technologies. In this perspective, we highlight the processing science and scaleup capabilities of the Materials Engineering Research Facility (MERF) at DOE's Argonne National Laboratory to demonstrate how DOE National Laboratories bridge fundamental science and applied technology development to accelerate deployment. Case studies are presented on selective membranes for critical mineral recovery, sensors for per‐ and polyfluoroalkyl substances (PFAS) detection, surface functionalization via atomic layer deposition (ALD) and sequential infiltration synthesis (SIS), and lithium recovery from battery recycling waste streams using a novel electrodialysis process. These examples underscore MERF's role in translating innovative technologies into practical solutions for renewable water and critical resource recovery, which also leverage Argonne's analytical and computational capabilities. This perspective also outlines mechanisms for collaborating with the DOE national laboratories to strengthen partnerships across government, the national laboratories, academia, and industry.

Electrodialysis (ED) is a promising seawater desalination technology using electricity. However, the existing research studies on ED mainly focus on design of electrode materials and device structure. The ED is a multiscale and multi-physical process with multiple influencing parameters. Under these circumstances, the complicated ED process needs to be unified for understanding its physical essence and further optimization. In the current work, a similarity principle-based multiscale model is constructed to analyze ion migration mechanism inside ED device. The multiscale model is developed by correlating cation and anion concentration difference in a mesoscopic nanopore with macroscopic space charge density. On the basis of non-dimensionalization of Poisson-Nernst-Planck equations, the mesoscopic model of ED is unified with three dimensionless variables instead of eight-dimensional input parameters, which can be categorized as representative of ion absorption capability, ion transport characteristic, and nanopore characteristic. Then, the macroscopic model of ED is further unified using 6 dimensionless variables instead of 12-dimensional input parameters, and their physical meaning include ion absorption capability, ion transport characteristic, ion migration driving force, and desalination tank characteristic. The similarity principle of multiscale ED process is verified through nine dimensional different cases with identical dimensionless variables. The dimensionless cation-anion difference in nanopores of mesoscopic model varies within 0.25%, and the dimensionless outlet Na⁺ concentration of macroscopic model changes within 0.05%. Besides, a multi-physical sensitivity analysis is also carried out using the Taguchi method to clarify dominant parameters for ED. The Taguchi sensitivity analysis quantifies parameter contribution to seawater desalination rate in ED as seawater temperature 39.74%, initial ion concentration 15.94%, applied electric potential 15.91%, desalination tank length 11.45%, ion exchange membrane porosity 8.76%, and seawater flow velocity 8.19%. The current work lays a theoretical foundation for developing experimental correlations of ED, and it also contributes to rapid sampling generation in artificial intelligence prediction.

Electrodialysis is an efficient separation and recovery method for ionic species such as sulfate ions. The batch operation of the electrodialysis process unit involves several decisions that affect its separation and economic performance. An optimal control system is developed that monitors the separation efficiency under real-time conditions and identifies the most suitable operating profile for the applied current voltage and the recirculation flow rate. A dynamic model is employed for the electrodialysis process, which is subsequently utilized within a dynamic optimization framework that aims to meet the separation and recovery specifications in the most economical way while satisfying the operating constraints. A discretized model using orthogonal collocation on finite elements enables the calculation of the optimal profile for the current voltage using nonlinear programming techniques. The control system has been successfully applied in the compensation of process disturbances mainly attributed to the variation of the membrane activity and other factors. Under severe membrane-activity loss (50-65%), the adaptive control profile achieved an increase of 34.9% in the degree of separation while limiting the batch-time penalty to 15.5% at the expense of higher energy consumption. An optimization problem is further formulated that determines the optimal design and operational characteristics of an industrial-scale size unit. In addition to the control variable profiles, the membrane surface that minimizes a comprehensive objective function is calculated. The objective function incorporates several targets for the electrodialysis process, such as batch duration, energy requirements, achieved degree of separation, membrane size, and control action behavior. The obtained optimal solutions are analyzed by Pareto front methods to reveal the critical trade-offs among the various competing objective function terms. The proposed approach enables the efficient separation of ions by electrodialysis in a diversely operating environment.

Electrodialysis is an energy efficient method for water desalination and resource recovery; however, the lack of ion selectivity in conventional ion-exchange membranes limits its performance, particularly in separating monovalent and divalent cations. In this study, we present the design and fabrication of mechanically reinforced graphene oxide (GO)-covalent organic framework (COF) composite membranes with variable selectivity for monovalent over divalent cations, enhancing the performance of electrodialysis processes. The composite membranes, created by stacking GO and sulfonate-functionalized COF nanosheets, exhibit a nacre-inspired "brick-and-mortar" structure that imparts mechanical robustness and high ion selectivity. By adjusting the GO-to- COF ratio, we achieved varying Na+/Ca2+ and Li+/Ca2+ selectivity ratios, reaching up to 15.34 and 6.99, respectively, without compromising the charge efficiency (greater than 75%). The membranes have also shown good stability in synthetic hypersaline brine. These results demonstrate the potential of GO/COF membranes for high-performance, energy-efficient ion separation in electrodialysis, offering a promising solution for desalination, wastewater treatment, and resource recovery.

Lithium hydroxide, which is utilized in lithium-ion battery applications, is produced as an intermediary from lithium sulfate (Li2SO4) in the conventional lithium extraction process. This work represents a more convenient way for the production of LiOH from lithium sulfate using the bipolar membrane electrodialysis (BMED) process at various applied potentials. Here, we have prepared the bipolar membrane (BPM) using the solution casting technique, having an interfacial layer (IL) of sulfonated molybdenum sulfide (S-MoS2) to boost the water splitting rate. Sulfonated poly(ether sulfone) and quaternized poly(phenylene oxide) were used as the cation exchange layer (CEL) and the anion exchange layer (AEL) in the bipolar membrane (BPM), respectively. Various characterization techniques, such as NMR, FE-SEM, UTM, and XRD, were carried out for the membranes and the S-MoS2 catalyst. The current-voltage curves (CVCs) for the prepared BPMs were recorded in 0.1 M LiCl to evaluate the various operational parameters for the BMED process. The feed solution of 0.4 M Li2SO4 produced 0.62 M of LiOH. To produce high-purity LiOH, dilute H2SO4 was circulated in the acid compartment (Acid mode), which reduced the migration of sulfate ions from the acid to the base compartment. This reduced the average sulfate flux from 0.034 × 10-4 mol m-2 s-1 to 0.021 × 10-4 mol m-2 s-1 for the dissociation of 0.2 M Li2SO4 at 6 V/pair. All Acid-mode experiments showed more than 90% lithium recovery and higher product purity with an energy consumption of 1.77 kWh kg-1. After further reducing the sulfate content, battery-grade LiOH could be obtained. This work illustrates that the BMED process can effectively produce LiOH from Li2SO4 and replace the conventional solvent extraction and chemical precipitation process by excluding the large amounts of bases, related precipitation, and solid-liquid separation steps.

This article considers the possibility of processing sodium sulfate (Na2SO4) solutions generated in various industrial processes into valuable products - sulfuric acid (H2SO4) and sodium hydroxide (NaOH) using the electrodialysis method. The problem of processing sodium sulphate solutions is relevant due to their significant volume and high content of inorganic impurities, while traditional methods of purification are energy-intensive and economically inexpedient. The authors have analysed the existing methods of obtaining and processing sodium sulphate solutions by electrodialysis using MC-40, MA-41 and MB-2I membranes and Ralex BM membranes. In purpose of electrodialysis the schemes of 3-chamber and 6-section electrodialyzers using cation- and anion-exchange membranes of MC-40, MA-41 (RF) and EDC1R, EAC1R (PRC) grades were applied. The scheme of bench installation of a multichamber electrodialyzer using EDAM and EDCM membrane brands was considered. The conditions of experiments on 3 installations according to the method of probabilistic-deterministic planning of experiments by Malyshev V.P. The dependences for the first installation were obtained: the degree of conversion on the concentration of Na2SO4, the duration of the process on the cathodic density and the content of MgSO4 impurity. Dependences of energy consumption on concentration of initial solution and current density at 3 installations allow to judge about expediency of electrodialysis process.

Molecular insight into crown ether graphene membranes for the separation of Co2+/Mg2+ in electrodialysis processes

Development of piperidinium-grafted anion exchange membranes for desalination applications via electrodialysis process

Significantly improved antibiotics removal and material utilization in novel electrodialysis integrated with nanostructured carbon microspheres.

Effect of organic fouling on nutrient recovery from municipal wastewater in magnesium anode-based electrodialysis processes

Carbon capture, utilization and storage (CCUS) technologies are pivotal in mitigating the rise in atmospheric CO2 and promoting sustainable development. We have been focusing on electrochemical CCU processes, which offer the advantage of operation at ambient temperature and pressure. We developed a novel system combining direct air capture and direct electrochemical (bi)carbonate reduction, mediated by a KHCO3–K2CO3 mixed solution (C-solution), and demonstrated a cooperative CCU operation.1 The current efficiency for CO production, η CO, in this system is still low, so that an important challenge is to improve η CO and reduce energy consumption per produced CO. Previous research demonstrates that η CO reaches 90 % when a CO2 electrolyzer is operated with a C-solution containing high-activity CO2 (i.e., CO2-saturated KHCO3 aqueous solution).2 This suggests that η CO should increase if an air-derived C-solution could be activated in some process, which motivates us to study electrodialysis processes. In this talk, we report our recent efforts to improve the energy consumption and the processing rate of dissolved inorganic carbon (DIC, consisting of CO3 2−, HCO3 −, dissolved CO2) in electrodialysis processes by investigating the effects of mass transports in liquid-phase compartments on electrodialysis performances.An electrodialysis process was studied in the configuration as schematically shown in Fig. 1. A CO2-absorbing solution in equilibrium with atmospheric 0.4 mbar CO2(g), which was simulated by the C-solution containing 0.136 mol dm−3 K+ and 0.100 mol dm−3 DIC, was supplied at 1 cm3 min−1 to the middle compartment sandwiched between two cation exchange membranes (CEM, Nafion N115, Chemours). The effect of an electrolyte additive was investigated by adding K2SO4 to the above simulated C-solution. A C-solution containing the lower concentrations of K+ and DIC than that introduced to the middle compartment (0.100 mol dm−3 K+ and 0.067 mol dm−3 DIC) was supplied to the cathode compartment at a standard flow rate of 1 cm3 min−1. The anode compartment was supplied with humidified Ar gas at 30 cm3 min−1. The cathode and anode were a 250-nm Pt thin film deposited on a carbon paper (TGP-H-060, Toray) and IrO2 nanoparticles coated on CEM, respectively. The geometric area of each electrode was set to 6.25 cm2. Constant currents were applied between the two electrodes with a potentiostat/galvanostat (SP-240, BioLogic) to induce not only electrode reactions but also inter-compartment cation transfers. The degree of progress in DIC activation, P, and the current efficiency for the reaction, η DIC, were evaluated from the concentrations of K+ in C-solutions before and after passing through the electrodialysis cell, which were measured with an ion chromatograph (ICS-5000+, Thermo Fischer Scientific) and a potassium ion electrode (HM-40P, DKK-TOA).Regarding the electrodialysis process shown in Fig. 1, we investigated the effects of electrolyte additives in the simulated CO2-absorbing solution and the solution flow rate in the cathode compartment on the energy-related performances of the electrodialysis cell (Fig. 2). Figure 2a indicates that addition of an electrolyte additive (0.050 mol dm−3 K2SO4 for example) decreases voltages during the electrodialysis operation at different constant currents. This is due to decrease in the ionic resistance of the middle compartment brought by the electrolyte additive. Figure 2b describes that increase in the flow rate of the C-solution in the cathode compartment increases η DIC during the electrodialysis operation. This would be caused by preventing the accumulation of the K+ ion coming from the middle compartment in the space between the cathode sheet and the neighboring CEM. In addition to the above efforts, the energy consumption in an electrodialysis process for DIC activation to CO2 can be further improved by making the most of the byproducts formed in electrode reactions. The processing rate of DIC can be increased not only by increasing the applied current but also by rearranging the components of an electrodialysis cell. We have also been investigating these effects on the performances of electrodialysis-utilizing electrochemical processes, which will be discussed comprehensively on the basis of our experimental and simulating works in the conference. References Y. Sakamoto, Y. Nishimura, Y. Mizutani, S. Mizuno, R. Hishinuma, K. Okamura, Y. Takeda, and M. Iwasaki, Carbon Capture Sci. Technol., 12, 100225 (2024).E. R. Cave, J. H. Montoya, K. P. Kuhl, D. N. Abram, T. Hatsukade, C. Shi, C. Hahn, J. K. Nørskov, and T. F. Jaramillo, Phys. Chem. Chem. Phys., 19, 15856 (2017). Figure 1

ABSTRACT Electrodialysis plays an important role in lithium extraction from brine. A two‐dimensional mathematical model for steady electrolyte transport during electrodialysis desalination is constructed in this study to uncover the mechanism of lithium‐ion transfer and forecast the behavior of electrodialysis. The effects of ionic charge number, ion diffusion coefficient, applied voltage, and channel flow rate on mass transfer are examined by analyzing the distributions of the lithium‐ion concentration, electric potential, and flux in an electrodialysis device. Results demonstrate that an increase in the ionic charge number resulted in an increase in both the electromigration flux and the total flux. Ionic charge is the primary factor influencing ion flux. The larger the diffusion coefficient, the greater the total transfer flux and electromigration flux of Li + . High applied voltages and channel flow rates are beneficial for increasing the overall Li + transfer flux. Furthermore, model validity is confirmed by comparing simulation results with experimental electrodialysis data. This study aims to develop a complete model for lithium recovery through electrodialysis by rationalizing and integrating previously neglected assumptions. It elucidates the sensitivity of the electrodialysis process to various parameters and provides guidelines for optimizing design, material selection, and operating conditions. Furthermore, the model can be employed to narrow the parameter range for experimental investigations of selectivity, thereby offering theoretical guidance and data references to facilitate the process optimization of electrodialysis‐based lithium‐ion recovery.

Exploring the potential of single-batch and multi-batch electrodialysis treatment of domestic wastewater for resource recovery.

This study investigates processes related to processing sodium chloride solutions at a concentration of 3.5–120 g/dm3 by electrodialysis to solve the task of utilizing chlorine-containing concentrates of membrane water desalination to obtain active chlorine. When electrolyzing the solutions, open and sealed two-chamber electrolyzers with an anion exchange membrane MA-41 were used. Solutions with NaCl were placed in the anode chamber, and the cathode chamber was filled with NaOH solutions (200–1000 mg-equiv./dm3). The electrolysis processes were carried out at an anode current density of 1.67–12.5 A/dm2. With an increase in the anode current density and chloride concentration in the solution, the intensity of chloride oxidation increases. During the anodic oxidation of chlorides, hypochlorites and chlorides are formed along with the formation of chlorine in the presence of hydroxides. This confirms the ratio of the amounts of active chlorine and oxidized chlorides. Prolonging the electrolysis time in an open electrolyzer does not contribute to an increase in the concentrations of oxidized chlorine in the anolyte because of its significant degassing. At low initial chloride concentrations (60 mg-equiv./dm3) and at low anodic current density (J = 0.83 A/dm2, 1.67 A/dm2), the yield of sodium hypochlorite reached 100.0–87.0%, respectively. At a current density of 4.17 A/dm2 and the same NaCl concentration, the yield of sodium hypochlorite decreased to 51.2%. The concentration of active chlorine in the solutions did not exceed 80–90 mg-equiv./dm3. When using a sealed two-chamber electrolyzer, the bulk of the active chlorine was concentrated in the anolyte. To capture active chlorine vapors, gases from the anode zone were passed through a NaOH solution in the absorber. The concentrations of active chlorine in the anolytes reached 1240–1920 mg-equiv./dm3. The degree of degassing of active chlorine did not exceed 11–17%

Nitrates and nitrites are natural components of the environment and contribute to the nitrogen cycle on Earth. Although nitrogen is essential for life, nitrogen compounds are among the main pollutants in the ecosystem. High concentrations of nitrogen compounds in the groundwater are primarily caused by human activity mostly in the use of chemical fertilizers in agriculture. Common health risks associated with higher concentrations of nitrates give rise to methemoglobin, which negatively affects mainly infants, and the potential formation of carcinogenic nitrosamines. This paper summarizes the results of laboratory tests of electrodialysis to remove nitrates from the model water. For the model solutions we used NaNO3 and NaNO3 with NaCl with a concentration of nitrates of approximately 1000 mg/l. The aim of the test was to achieve a concentration of nitrates corresponding to the limit for drinking water, which is 50 mg/l. The tests were carried out in the batch mode, and semi-continuous mode. All the tests have demonstrated the effectiveness of nitrate removal around 90%.

The collapse of the Fundão dam in Mariana, Minas Gerais, Brazil, affected the Gualaxo do Norte, Do Carmo, and Doce rivers, as well as part of the Brazilian coastline. Studies indicate the presence of metallic ions along the route and the need to treat water for human consumption. These studies also show the impact on the surrounding fauna and flora. Electrodialysis and anion-exchange membranes (AEM) are emerging as an alternative methods for removing metallic ions. This study aimed to use an electrodialysis cell with heterogeneous ion-exchange membranes incorporating resins and a graphene oxide (GO) solution at proportions of 5.0% and 2.5% (m/m), respectively. Tests were carried out to remove Mn2+ ions in a synthetic effluent using an electrodialysis cell. More than 90% of the diluted solution was removed using polysulfone membranes with GO, both before and after cleaning. The removal percentages of Mn2+ ions exceeded 94% for the ion-exchange membranes and 95% for the membranes with GO, even after regeneration. The membranes were regenerated with 0.1 M NaCl and HCl solutions and then reapplied to the electrodialysis process. Removal rates exceeded 90% for membranes regenerated with the addition of GO. Samples were collected and characterized for suspended solids, with concentrations of 0.23 and 0.13 g/L in the Gualaxo do Norte and Doce rivers, respectively. Metallic ion concentrations were 0.67 and 0.42 g/L for Cr6+, 239.18 and 83.96 mg/L for Fe2+, and 12.39 and 2.39 mg/L for Mn2+ in the Gualaxo do Norte and Doce rivers, respectively. Using samples collected from the rivers in an electrodialysis cell with polyethersulfone membranes and 2.5% graphene oxide added showed removal rates of 72.8%, 91.3%, and 85.7% for chromium, iron, and manganese, respectively. Adding GO proved promising for producing heterogeneous ion-exchange membranes, showing potential for metal-ion removal applications in different contaminated effluents.

Precise separation of ions of the same polarity and similar valence and size remains a critical need in resource recovery from waste streams. Here, we report the rational design and scalable fabrication of a thin film nanocomposite (TFN) cation exchange membrane to achieve precise selectivity for lithium over competing cations. The precise selectivity is realized by an ultrathin polyamide (PA) layer incorporated with amine functionalized β-monoclinic lithium titanium oxide (N-LTO) nanoparticles using a scalable interfacial polymerization process that allows high N-LTO loading while minimizing interfacial defects. The TFN membrane demonstrates superior Li+ permeability, with Li+/Ca2+ and Li+/Na+ selectivity reaching 173.90 and 13.58, respectively. The Li+/Na+ selectivity is attributed to the Li+-exclusive transport pathway in the layered structure of the N-LTO, whilesize exclusion bythe highly cross-linked N-LTO-PA also contrubutes tothe Li+/Ca2+ selectivity. Molecular dynamics simulation shows that the electrical field drives Li+ dehydration and accelerates the migration of the dehydrated Li+ while Na+ is blocked due to its larger size than the Li+ cavity. The high Li+ selectivity and permeability enable energy-efficient, precise, and chemical-free lithium extraction using the electrodialysis process. TheTFN membranearchitecture also allows simple and scalable fabrication of a multi-functionalpolymer-inorganic nanocomposite membrane.