Electrodialysis Technique Research Articles

Towards Sustainable Lithium-Ion Battery Recycling: Advancements in Circular Hydrometallurgy

The growing demand for lithium-ion batteries (LIBs) has led to significant environmental and resource challenges, such as the toxicity of LIBs’ waste, which pose severe environmental and health risks, and the criticality of some of their components. Efficient recycling processes are essential to mitigate these issues, promoting the recovery of valuable materials and reducing environmental pollution. This review explores the application of electrodialysis in the process of recycling LIBs to contribute to the principles of circular hydrometallurgy. The article is structured to provide a comprehensive understanding of the topic, starting with an overview of the environmental and resource challenges associated with manufacturing LIBs. Then the current recycling processes are presented, focusing on hydrometallurgical methods. The concept of circular hydrometallurgy is introduced, emphasizing sustainable resource recovery. The electrodialysis technique is described in this context, highlighting its integration into the process of recycling LIBs to separate and recover valuable metals. Finally, the article addresses the challenges and limitations of the electrodialysis technique, such as energy consumption and system optimization, and identifies areas for future research and development. Through this analysis, the review aimed to contribute to advancing the development of more sustainable and efficient LIB recycling technologies, ensuring a safer and more environmentally friendly approach to the management of batteries’ lifecycle.

Large‐Area Graphene‐Based Ion‐Selective Membranes with Micro/Meso‐Pores for Osmotic Energy Harvesting

AbstractRenewable osmotic energy between seawater and river water shows great potential in meeting global energy demand. Reverse electrodialysis (RED) technique using ion‐selective membrane is particularly outstanding for its easy operation. Preparing low‐cost and large‐area ion‐selective membranes with excellent ion transport characteristics is particularly important to promote commercial applications. Herein, large‐area ion‐selective membrane is prepared by scraping slurry of flocculated GO (graphene oxide)/PAAS (sodium polyacrylate) solution and then coated with PVA (polyvinyl alcohol)/SA (sodium alginate) gel layer. The PVA/SA molecules can penetrate into the membrane through the unique micro/meso‐pores, which together increase the ion selectivity, membrane permeability, and stability. This ion‐selective membrane can achieve a power density of 8.65 W m−2 under a 50‐fold salinity gradient (NaCl) simulating the sea/river junction environment (with the testing area of 0.0314 mm2). This work significantly promotes the application of GO in large‐area preparation of low‐cost ion‐selective membrane.

Advancements in Bipolar Membrane Electrodialysis Techniques for Carbon Capture.

Bipolar membrane electrodialysis (BMED) is a promising technology for the capture of carbon dioxide (CO2) from seawater, offering a sustainable solution to combat climate change. BMED efficiently extracts CO2 while generating valuable byproducts like hydrogen and minerals, contributing to the carbon cycle. The technology relies on ion-exchange membranes and electric fields for efficient ion separation and concentration. Recent advancements focus on enhancing water dissociation in bipolar membranes (BPMs) to improve efficiency and durability. BMED has applications in desalination, electrodialysis, water splitting, acid/base production, and CO2 capture and utilization. Despite the high efficiency, scalability, and environmental friendliness, challenges such as energy consumption and membrane costs exist. Recent innovations include novel BPM designs, catalyst integration, and exploring direct air/ocean capture. Research and development efforts are crucial to unlocking BMED's full potential in reducing carbon emissions and addressing environmental issues. This review provides a comprehensive overview of recent advancements in BMED, emphasizing its role in carbon capture and sustainable environmental solutions.

Galactonate bio-preparation from cheese whey waste and its application as a novel bio-retarder

Cheese whey, as the major byproduct in cheese making, contains significant amounts of lactose, which can be efficiently hydrolyzed to glucose and galactose. Therefore, it is a potential resource for producing gluconic acid (GA) and galactonic acid (GalA) by Gluconobacter oxydans (G. oxydans). The glucose can be preferentially and rapidly bio-oxidized into GA by G. oxydans, however, the preserved GA and galactose would be simultaneously metabolized, meaning that the GA and GalA cannot be co-produced. Therefore, based on the kinetics of biphasic trend for glucose and galactose metabolism, a novel approach involving the integration of bio-oxidation and electrodialysis techniques was developed to sequentially convert glucose and galactose into GA and GalA, correspondingly. As a result, 79.2 g/L GA and 75.1 g/L GalA could be co-produced step by step from the enzymatic hydrolysate that contain approximately 80 g/L glucose and 80 g/L galactose. Furthermore, in this study, the evaluation experiment of GalA as cement additive suggested that it could be used as a novel bio-retarder with an excellent retarding effect, providing a new idea for cheese whey waste utilization.

Comparable investigation for incorporation of zirconium MOF@PVDF membrane as cation selective membranes for lithium-ion separation

To improve the efficiency of lithium-ion separation and removal from contaminated water, the performance of zirconium MOFs as filler for PVDF composite membranes in lithium-ion separation was investigated in this work utilizing the electrodialysis technique. Two different cations selective PVDF-based membranes, UiO-66/PVDF and UiO-66/ZIF-8/PVDF were casted using the phase inversion technique. Various spectroscopic techniques were utilized to validate the physicochemical properties of fabricated PVDF composite membranes, which include FTIR, XRD, SEM, and XPS. It was evident that the fabricated UiO-66/ZIF-8/PVDF membrane exhibits superior lithium-ion removal (94 %) from contaminated water, compared to the UiO-66/PVDF membrane which exhibits 75 % removal at a high Li ion concentration (400 ppm). It was evident that the UiO-66/ZIF-8/PVDF membrane exhibits adsorptive qualities towards Li-ion removal, making it more appropriate for water treatment. In contrast, UiO-66/PVDF showed higher cation migration capabilities, which is encouraging for lithium recovery. These different separation mechanisms of the fabricated PVDF-based composite membranes toward Li ions are owed to the properties and the functionality of MOFs utilized as membrane fillers beside the intercalated pore structure of the fabricated composite membrane that produces ion channels with ion adsorptive characteristics. The promising features of the fabricated composite membranes render them suitable for lithium separation from contaminated water.

Three birds with one stone: Full-component recovery of strongly acidic arsenic complex wastewater via combining electro-redox and electrodialysis

Full-component green recovery of As-contained acid wastewater shows great prospect demanding on both urgent resource need and environment protection. In this work, we firstly constructed a three-chamber electrochemical system for full-component recovery of As-Cu acidic wastewater, combining electrochemical redox and electrodialysis techniques to recover metals and acids simultaneously. In which CeO2@CC and Cu plate electrode materials were selected and the middle chamber was separated by cation-exchange membrane (CEM) and anion-exchange membrane (AEM). In the anode chamber, 93.84% As(III) was oxidized and adsorbed by the CeO2@CC anode within 2 h. Meanwhile, 100% copper was reduced and deposited on the cathode. The pH of the intermediate chamber solution was reduced to 1.2. Besides, economic benefits and carbon emission accounting indicated that the system has better economic and environmental benefits for the full-component recovery of As-Cu strongly acidic wastewater. This work brings a new insight in future wastewater resource recovery and purification.

Embedding MXene nanosheets into cation exchange membranes to enhance power generation by reverse electrodialysis

Electrical energy can be extracted from the mixing of two water streams with different salinity through the reverse electrodialysis (RED) technique. Ion exchange membranes (IEMs) are vital components for capturing the energy in the RED systems. Therefore, the design and fabrication of IEMs are essential to the enhancement of power production by the RED system. In this work, the novel cation exchange membranes (CEM) were prepared by sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) as a polymer and MXene nanosheets as filler for the first time. The effect of polymer concentration and MXene loading on the electrochemical properties, membrane structure, and gross power output in the RED system was investigated in detail. An increase in MXene additive (0 to 2 %) significantly increased the permselectivity from 77.40 % to 91.25 %, and reduced the area resistance from 4.7 to 1.3 Ω.cm2 of fabricated CEMs (sPPO: 22 wt%). The results also showed that CEM was prepared by a solution containing 22 wt% of sPPO (1 wt% of MXene additive), and 19 wt% of sPPO (2 wt% of MXene additive) exhibited relatively desirable electrochemical properties for power generation. These membranes presented the highest gross power density (1.45 and 1.37 W.m−2, respectively) in RED experiments, which were significantly higher than the commercially available CMX membrane (1.01 W.m−2).

Direct copper recovery from pregnant leaching solutions (PLS), using a custom electrolytic cell, based on reactive electrodialysis (RED)

ABSTRACT This study shows the feasibility of recovering copper directly from Pregnant Leaching Solutions (PLS), using the reactive electrodialysis technique, without the need of solvent extraction. The copper PLS contained the following ion concentrations: Cu2+ 2.0–2.5 g/L; pH 1.5–1.8; 90–95 g/L; Cl− 8–10 g/L and total iron of 8–10 g/L. The copper electrowinning process is limited by the mass transport capacity of the system and by impurities that decrease the yield. To increase the selectivity and the copperproduction rate, a reactive electrodialysis (RED) cell was developed. The cell contained four compartments, two anion-exchangemembranes and a bipolar electrode to increase the production rate. This cell recovered copper and sulfuric acid at the anolytes. Thebest result was a current efficiency of 99% and specific energy consumption of 2.11 Wh/kg Cu using a current density of 80 A/m2 at 55°C and flow of 100 mL/s.

Effect of Different Parameters on Lithium Ion Transfer through PVDF-UIO-66 Cation Selective Hybrid Membrane via Electrodialysis Technique

This study aims to increase the efficiency of Li ion recovery via electrodialysis technique by manipulating several parameters. The membrane used for this study consists of a polymer matrix that acts as a backbone, and a metal organic framework (MOF) that acts as the cation selective agent. Polyvinylidene fluoride (PVDF) was chosen for this study due to its mechanical properties and chemical stability. UIO-66 was chosen as the cation selective MOF and prepared via hydrothermal method and characterized using XRD. The membrane matrix was synthesized using phase inversion casting technique. After casting, the membrane was characterized using XRD and FTIR to ensure that the MOF was successfully embedded. The investigated operation parameters are voltage applied, initial Li ion concentration, and time of operation. The tests were conducted at a selected value of each other controlled variable while manipulating only one variable at a time. The studied concentrations were 100, 200, 300, and 400 ppm, while the applied voltage varied from to 10 to 40 V with a 10 V step. The time parameter studeid was 1, 2, 3, and 4 hrs. This study aims to show the parameters’ effects on the recovery of the lithium ion. The highest recovery was recorded for each parameter.

Bio-Inspired Salinity-Gradient Power Generation With UiO-66-NH2 Metal-Organic Framework Based Composite Membrane.

Salinity-gradient directed osmotic energy between seawater and river water has been widely considered as a promising clean and renewable energy source, as there are numerous river estuaries on our planet. In the past few decades, reverse electrodialysis (RED) technique based on cation-selective membranes has been used as the key strategy to convert osmotic energy into electricity. From this aspect, developing high-efficiency anion-selective membranes will also have great potential for capturing osmotic energy, however, remains systematically unexplored. In nature, electric eels can produce electricity from ionic gradients by using their “sub-nanoscale” protein ion channels to transport ions selectively. Inspired by this, here we developed a UiO-66-NH2 metal-organic framework (MOF) based anion-selective composite membrane with sub-nanochannels, and achieved high-performance salinity-gradient power generation by mixing artificial seawater (0.5 M NaCl) and river water (0.01 M NaCl). The UiO-66-NH2 metal-organic framework based composite membranes can be easily and economically fabricated with dense structure and long-term working stability in saline, and its performance of power generation can also be adjusted by pH to enhance the surface charge density of the MOF sub-nanochannels. This study will inspire the exploitation of MOFs for investigating the sub-nanochannel directed high-performance salinity-gradient energy harvesting systems based on anion-selective ion transport.

Carbon dioxide capture coupled with magnesium utilization from seawater by bipolar membrane electrodialysis

Carbon dioxide (CO2) capture coupled with further mineralization in high value-added form is a great challenge for carbon capture utilization and storage (CCUS) processes. In this work, a bipolar membrane electrodialysis (BMED) technique integrated with crystallization chamber was proposed to utilize CO2-derived carbonates and the residual magnesium resource from seawater to produce functional nesquehonite. To ensure the stable CO2 storage and magnesium extraction by BMED process, the metastable zone during nesquehonite crystallizing was first measured to modulate crystallization rate, obtain high-quality crystal products and inhibit membrane fouling states. Subsequently, the effects of current density, temperature, and CO2 flow rate during the whole BMED-crystallization process were further investigated. The increase in current density and temperature was conducive for the extraction of magnesium while the enlarged gas flow rate induced higher absorption of CO2. Under the current density at 22 A/m2, CO2 flow rate at 50 mL/min and temperature at 30 °C, the optimal carbon absorption ratio and the magnesium extraction ratio reached 50.85% and 56.71%, respectively. Under this condition, the explosion nucleation of the nesquehonite was effectively avoided to inhibit membrane fouling and the generation of magnesium hydroxide was depressed to obtain the target product nesquehonite. This study on simultaneous carbon capture and magnesium utilization provides theoretical guidance for the industrial green storage of CO2 and development of valuable magnesium products.

Application of electrodialysis technique in removal of some heavy metal ions from discharge wastewater in paper industry

Application of electrodialysis technique in removal of some heavy metal ions from discharge wastewater in paper industry

Numerical Investigation for The Valorization of Waste from HMD Cell Using Electrodialysis

The Hydromagnetic desalination (HMD) system is a continuous process with several advantages, including a high water recovery ratio, and can be favored economically by producing several industrial byproducts instead of discharging the highly concentrated brine to the environment. In the current work, the ions concentration in the Electrodialysis (ED) technique is simulated using COMSOL Multiphysics V.5.2 software. The ED cell simulated in this paper contains two selective membranes (anion and cation) with a width of 0.25 mm each. The salt is to be taken away in the middle domain. The cell operation has been simulated to separate the sodium and chlorine ions from the HMD brine waste solution at 40 or 55ºC temperatures at different voltages and concentrations. In this two-dimensional model, the Nernst-Plank equation has been used to describe ion flux and charge transport in the electrolyte solution. Secondary current distribution theory and the electroneutrality condition have been used in the mathematical model. Finally, Donnan equations have been used to provide the exact fulfillment of boundary conditions for constant voltage mode. The simulation shows that the highest efficiency is obtained at high temperatures and voltage with the lowest feed concentration. Finally, the results have been validated using experimental data from the literature, and a satisfying agreement has been found.

Demonstration of bipolar membrane electrodialysis technique for itaconic acid recovery from real fermentation effluent of Aspergillus terreus

The scientific interest towards itaconic acid (IA) recovery (produced industrially from biomass by fermentation) significantly increased from around the last decade. IA is a value-added chemical with key-role in the production of versatile polymers and is potentially able to replace certain petrochemical-based materials. Typically, multi-step crystallization is used as a downstream process for IA recovery but there are several promising alternatives. One of them is the application of electrodialysis in the concept of integrated fermentation-membrane system. However, there are still limited publications in this topic especially dealing with the processing of real IA fermentation broth. Hence, in this study, the feasibility of IA separation was assessed from fermentation broths (containing 22−25 g/L of IA) produced by Aspergillus terreus using commercialized electrodialysis unit applying mono- and bipolar membranes. The experimental results showed that the IA recovery ratio/current efficiency were 74%/77% and 63%/41% under initial pH of 3.0 and 7.4, respectively. It was also found that higher initial pH resulted in faster IA separation thanks to the presence of additional mobile ions but at the same time, it decreased the current efficiency. Moreover, partial retain of colorants could be attained during the separation. However, the by-products decreased the separation efficiency compared to our previous measurements conducted with model IA solutions.

Electrodialysis based waste utilization methodology for the desalination industry

High salinilty wastewater and carbon dioxide are major hurdles in implementing a sustainable desalination technology. This study proposes an electrodialysis (ED) technique for onsite utilization of desalination reject brine into value-added products, such as carbonate salts and inorganic acid. The parameters that defined the overall system performance included the current efficiency, the mass of captured CO2, metal removal percentage, total energy consumption, and specific energy consumption. Sodium chloride (NaCl) is used as representative of saline wastewater. The effects of NaCl concentration, CO2 flow rate, and voltage on the process performance are evaluated. A six-chamber ED cell with a batch circulation process for the CO2 chamber with a cathodic chamber is adopted to investigate the process. The ED cell contained cation-exchange membranes, anion-exchange membranes, and electrodes. Membranes are arranged in a specific pattern to collect hydrochloric acid and carbonate salts in separate chambers. NaCl solution and a gas mixture containing 10% CO2 and 90% N2 are used as feed to the ED cell. The cathodic and CO2 chambers are linked to each other through the batch circulation mode. The anode and cathode are made of titanium, and the anode is coated with mixed oxides of iridium and platinum. The current efficiency, mass of captured CO2, metal (sodium) removal percentage, specific energy consumption, and total energy consumption ranged from 81.4%–99.8%, 3.88 g–8.2 g, 12.8%–38.7%, 352.9 g/kWh–435.2 g/kWh, and 0.023kWh–0.070kWh, respectively.

Removal of chloride ions from a copper leaching solution, using electrodialysis, to improve the uranium extraction through ion-exchange

This study shows the technical feasibility to recover uranium from copper Pregnant Leaching Solutions (PLS) using ion-exchange, after a removal of chloride ions using the electrodialysis (ED) technique. The original copper PLS solutions came from the National Copper Corporation (CODELCO), from their hydrometallurgical operations, which contained high concentrations of chloride ions. These solutions contained average concentrations of 22 g/L chloride ions, pH 1.5 – 1.8 and 20 mg/L uranium. The high chloride contents made the uranium recovery technically unfeasible, because of the high volumes of chemical reagents needed to operate. To eliminate the chloride ions selectively, a modified electrodialysis (ED) process was developed. The ED process was made of a three–compartment cell. This system removed selectively the chloride ions, and replaced them with sulphuric ions, without modifying the composition of the copper PLS solution, to allow a continuous operation of the copper production plant. The ED process decreased the chloride content from 22 g/L to 6 g/L. Finally, static and dynamic load tests were performed for both the original PLS and the treated PLS, using 3 different anion-exchange resins: Dowex-1, Lewatit A365 and Lewatit MP62-WS. The loading capacity of the ion-exchange resins was increased 4 times approximately.

Diffusion analysis and modeling of kinetic behavior for treatment of brine water using electrodialysis process

In this study, the removal of monovalent and divalent cations, Na+, K+, Mg2+, and Ca2+, in a diluted solution from Chott-El Jerid Lake, Tunisia, was investigated with the electrodialysis technique. The process was tested using two cation-exchange membranes: sulfonated polyether sulfone cross-linked with 10% hexamethylenediamine (HEXCl) and sulfonated polyether sulfone grafted with octylamine (S-PESOS). The commercially available membrane Nafion® was used for comparison. The results showed that Nafion® and S-PESOS membranes had similar removal behaviors, and the investigated cations were ranked in the following descending order in terms of their demineralization rates: Na+ > Ca2+ > Mg2+ > K+. Divalent cations were more effectively removed by HEXCl than by monovalent cations. The plots based on the Weber–Morris model showed a strong linearity. This reveals that intra-particle diffusion was not the removal rate-determining step, and the removal process was controlled by two or more concurrent mechanisms. The Boyd plots did not pass through their origin, and the sole controlling step was determined by film-diffusion resistance, especially after a long period of electrodialysis. Additionally, a semi-empirical model was established to simulate the temporal variation of the treatment process, and the physical significance and values of model parameters were compared for the three membranes. The findings of this study indicate that HEXCl and S-PESOS membranes can be efficiently utilized for water softening, especially when effluents are highly loaded with calcium and magnesium ions.

Fate of typical organic halogen compounds during electrodialysis process and improvement of their recoveries

According to an earlier study, electrodialysis (ED) can efficiently separate most organic halogenated micropollutants from inorganic halogens (i.e., halides and oxyhalides) in water, with only a few micropollutants being poorly-recovered. To optimize the ED process and to gain in-depth knowledge of the mechanisms responsible for their low recoveries, this study designed some experiments to examine the fates and transports of three hard-to-separate organic halogen compounds. Results show that the dominant mechanism responsible for the loss of trichlorophenol (TCP) is migration and retention in the ion exchange membrane (IEM), the dominant mechanism for the loss of trichloroacetic acid (TCAA) is ion exchange with the IEM, and the dominant mechanism for the loss of trichloroacetonitrile (TCAN) is volatilization and chemical decomposition during the ED process. Optimizing specific operating conditions (e.g., sealing, voltage, and membrane type, etc.) can improve recovery of these micropollutants to 70.4–95.8% while maintaining 90.4–99.5% removal of chloride. Even though TCAN underwent hydrolysis, we recovered 82.0% chlorine from TCAN and its hydrolytic products. These results may help not only better understand the fates and transports of organic micropollutants during the ED process, but also help facilitate application of electrodialysis technique for measuring total organic halogen.

Heterogeneous PVC cation-exchange membrane synthesis by electrospinning for reverse electrodialysis

AbstractBlue energy (or salinity gradient energy) is a renewable, carbon-neutral, and continuous electrical energy source that can be obtained via the reverse electrodialysis (RED) technique. The viability of this technology strictly depends on the performance and cost of the ion-exchange membranes (IEMs) that compose the RED units; designing the optimal membrane represents a critical challenge due to the complex relation between the performance, properties, and structure of the membrane. In this work, we present our findings on an electrospun cation-exchange membrane based on polyvinyl chloride (PVC), a strongly acidic cation exchange resin, with sodium dodecyl sulfate (SDS) as an additive. We contrast it with a similar membrane produced with the more conventional casting solution technique. The electrospinning technique provides thinner and more homogeneous membranes than those synthesized via casting. The membranes were characterized using morphological, spectroscopic, and analytical methods. Scanning electron microscopy images depicted an intertwined nanofiber mesh within the membrane. We also synthesized the same electrospun cation exchange membrane without SDS; this membrane presented 63% less swelling, and a significant increase in the fixed charge density (CDfix) (119.6 meq/g) when compared to its casting solution counterpart (34 meq/g). This suggests an enhanced permselectivity, and thus better performance for blue energy generation in RED units.

Biomimetic Nacre-Like Silk-Crosslinked Membranes for Osmotic Energy Harvesting

As an approach to harvesting sustainable energy from ambient conditions, the osmotic energy between river water and seawater contributes to solving global issues such as the energy shortage and environmental pollution. Current attempts based on a reverse electrodialysis technique are limited mainly due to the economically unviable power density and inadequate mass transportation of membrane materials. Here, we demonstrate a benign strategy for designing a multilayer graphene oxide-silk nanofiber-graphene oxide biomimetic nacre-like sandwich as an osmotic power generator. Enhanced interfacial bonding endows the composite membranes with long-term stability in saline, and meanwhile, the two-dimensional nanofluidic channel configuration also reduces the ion transport resistance and provides large storage spaces for ions. Thus, the output power density of the proposed membrane-based generator achieves a value of up to 5.07 W m-2 by mixing seawater and river water. Furthermore, we experimentally and theoretically demonstrate that the thermal-field drives the increased output power density due to the advances in ionic movement range and activity of electrode reaction, showing the promise of strengthened thermo-osmotic energy conversion.