Selective separation of metal ions with analogous physicochemical properties remains a fundamental challenge in complex aqueous systems. In particular, chromium (Cr(VI)) and vanadium (V(V)) frequently coexist in industrial streams and exhibit analogous chemical behaviors, making their selective separation difficult. Herein, a Hofmeister-guided anion regulation strategy is proposed to control the selective transport of Cr(VI) and V(V) in a carrier-conducted membrane electrodialysis system. Instead of modifying carrier chemistry, the coexisting anion environment is systematically tuned to regulate ion transport dynamics. The results demonstrate that coexisting anions exert distinct regulatory effects following a Hofmeister-type sequence (SCN- approximate to NO3- > Cl- approximate to SO42-). Chaotropic anions (SCN- and NO3-) strongly suppress the transport of both metal ions, whereas moderately hydrated anions (Cl- and SO42-) selectively inhibit V(V) migration while maintaining efficient Cr(VI) transport. Density functional theory calculations combined with binary-anion experiments revealed that this selectivity originates from competitive binding at carrier sites. By optimizing the Cl- concentration (0.4 mol & centerdot;L-1) and operating temperature (328 K), a high separation factor of 91.9 was achieved, with Cr(VI) recovery reaching 82.1% while V(V) transport was strongly suppressed to 4.8%. This study demonstrates that anion-environment regulation provides an effective approach for selective metal separation in electrodialysis systems, offering mechanistic insights into ion-specific transport control in complex aqueous environments.

Global industries such as steel pickling, fertilizer manufacturing, petroleum refining, and battery recycling generate millions of tons of acidic wastewater annually, especially from sulfuric acid, leading to serious economic and environmental burdens. However, Conventional electrodialysis (ED) is limited to concentrate H2SO4 beyond 15 wt%, limiting their industrial applicability, mainly due to electro-osmotic water transport and proton back-diffusion. In this work, a ladder electrodialysis (LED) configuration is proposed for the first systematic regulation of proton and water migration by introducing intermediate chambers that enable stepwise ion transport, thereby suppressing water crossover and reverse diffusion. The effects of membrane stack design, ladder chamber number, and current density on transport behaviors were comprehensively investigated. Furthermore, a commercial proton-blocking anion exchange membrane (ACM, Astom Co.) was integrated into the LED stack to enhance selectivity and reduce proton leakage. Under an initial acid concentration of 5 wt% and 40 mA/cm(2), LED alone achieved 14.46 wt% H2SO4, outperforming conventional ED with AMX (12.27 wt%) and ACM (13.92 wt%). When combined with proton-blocking membranes, the LED system enabled one-step concentration up to 19 wt% with a low specific energy consumption of 1.189 kWh.kg(-1)H(2)SO(4), which represents a similar to 55 % increase in final acid concentration compared to conventional ED with AMX (12.27 wt%). This study demonstrates a scalable, energy-efficient alternative to thermal evaporation, and highlights LED as a promising strategy for closed-loop acid recovery and industrial waste acid valorization.

The feasibility of an analogous reverse electrodialysis (RED) process for power generation and acid recovery from acidic waste streams in the steel industry is investigated in this study. A comprehensive model was established to simulate the transport phenomena and power generation, which was validated through experimental data. The simulated operation time was 3 h, during which an acid recovery rate of 41.7% was achieved, and the maximum output power density reached 30.37 μW·cm−2. The results demonstrated a strong dependence of output power density on the acid concentration, with a linear relationship within the tested range of 1.0–3.0 mol·L−1 HCl. An optimal flow rate range was identified that maximized power output, with the best value of 90 mL∙min−1. The differences in energy harvesting between the traditional acid diffusion dialysis process and our analogous RED process were demonstrated via simulation. The importance of system electroneutrality in driving ion migration and forming ionic currents was crucial for effective power generation. The analogous RED process is a promising solution for efficient acid recovery and power generation from industrial acid waste, offering a sustainable treatment approach.

The performance of concentration gradient batteries (CGBs) based on reverse electrodialysis technology is inevitably influenced by seasonal temperature fluctuations; however, these effects have not been thoroughly investigated. This study explored the temperature dependence of water and salt transport in CGBs using five different membranes over a temperature range of 5-45 degrees C to elucidate these impacts. The results indicated that the temperature dependence of current efficiency and voltage efficiency in CGBs was respectively controlled by permeation processes (including both water and salt) and membrane resistance. The temperature dependence of mass transfer in these membranes was associated with the characteristics of the species crossing the membrane (such as size) and, more significantly, with membrane properties, including water volume fraction and fixed charge density. Therefore, we proposed that controlling these membrane characteristics can modulate the influence of temperature on mass transfer and CGB performance. This research enhanced our understanding of how temperature affects mass transfer mechanisms in different membranes and provided valuable insights for improving energy conversion in CGBs and other membrane processes.

The increasing production of lithium ion batteries (LIBs) necessitates the development of green and sustainable technologies for their recycling. Unfortunately, most of the recycling technologies used are always associated with high energy and chemical reagents consumption, posing a great risk to the environment. Herein, we propose a photovoltaic driven carrier-facilitated electrodialytic membrane process for low carbon recovery of spent ternary LIBs. Elaborately fabricated multifunctional membranes enable this process to efficiently separate multiple metals in one-step with high solution purity of 99.6 % for lithium, ∼100 % for nickel, and 94.1 % for cobalt. Molecular dynamics simulations illustrate that the binding energy between metal-carrier is disrupted above the current density threshold, thereby facilitating rapid ion transport along a continuous pathway within the membrane. The resulting cobalt flux is 58 times that of the commercial flagship Neosepta@AMX membrane. Environmental assessment further indicates that this strategy achieves a significant reduction in GHG emissions by 74.4 % compared with Hydro, 68.5 % compared with Pyro, and 76.1 % compared with Direct. This work not only creates a greener path for spent LIBs recovery but also introduces an innovative electrodialytic membrane system design that has potential applications in other areas.

Concentration gradient batteries (CGBs) use electrodialysis and reverse electrodialysis to charge and discharge, respectively. An important factor hindering CGB efficiency is osmosis through ion exchange membranes (IEMs); however, adding an osmotic ballast to the dilute compartment reduces osmosis and improves CGB efficiency. Despite the importance of osmosis in CGB performance, there has been no evaluation of the effects of CGB parameters on performance with and without an osmotic ballast. Accordingly, our goal was to evaluate the effects of selected CGB parameters on various CGB performance metrics to inform future optimization of CGB designs. Results showed ballast addition improved current and round-trip energy efficiency and stabilized CGB performance across multi-cycle operation. However, ballast addition caused lower average (net) power densities due to its impact on IEM stack resistance and solution viscosity. Increasing the flowrate and decreasing the spacer thickness led to decreases in average net power densities. Importantly, the effect of IEM properties on CGB performance varied with ballast addition: low water permeability IEMs had greater and lower round-trip energy efficiencies without and with ballast, respectively, compared to low resistance IEMs. This work informs CGB parameter selection, demonstrates tradeoffs associated with osmotic ballast addition, and shows multi-cycle CGB operation is feasible.

To fulfill the industrial requirements of salt fractionation and recovery from saline wastewater, a two-chamber selective electrodialysis (SED) stack incorporating commercial monovalent selective anion exchange membranes was employed and investigated in this study. Three different initial concentration ratios of NaCl/Na2SO4, namely 1:1 (10 g/L:10 g/L), 3:1 (30 g/L:10 g/L), and 5:1 (50 g/L:10 g/L) were examined to simulate various scenarios of saline wastewater. The influence of applied current density on membrane selectivity and overall system efficiency was further evaluated. The results indicated that an increase in the NaCl fraction within the feed solution directly correlates with enhanced concentration and purity of Na2SO4 in the product, achieving purities exceeding 92 %. A lower current density contributed to improved concentration and purity of Na2SO4, whereas higher current densities were conducive to augmenting the concentration and purity of NaCl. Additionally, a linear correlation was observed between the volumetric water transport and NaCl migration. Through numerical simulations, the concentrations of Na2SO4 and NaCl in the effluent were predicted, facilitating a comparative analysis with the salt fractionation efficiency of commercial nanofiltration membranes. Subsequent assessments of energy consumption and current efficiency revealed that the SED system ensured high product concentration and purity at reasonably low energy consumption (0.22-0.28 kWh per kg NaCl) alongside a high current efficiency (83-89 %). These findings offer critical insights into the optimization of salt fractionation process and highlight its economic and technical feasibility for the sustainable management of industrial saline wastewater.

In confronting the widespread challenge of chromium (Cr(VI)) pollution in industrial effluents, this study pioneers the integration of flow electrode capacitive deionization (FCDI) with carrier-facilitated ion exchange membrane (IEM) for selective heavy metal removal, which offers a marked enhancement in selectivity and energy efficiency over conventional treatments. Our comprehensive study demonstrates that the synergistic system significantly optimizes Cr(VI) elimination from low-concentration effluents, achieving an unprecedented selectivity coefficient of 20.6 under optimal operational parameters. The system performance is critically influenced by the system's operational parameters, including current density and ion concentration, with lower current densities favoring reduced energy consumption and higher selectivity without compromising removal efficiency. The pronounced permeability coefficient suggested that the Cr(VI) transport in the membrane occurs via continuous pathways, rather than fixed-site jumping mechanism. Furthermore, this innovative configuration exhibits remarkable adaptability to fluctuating Cr(VI) and Cl-concentrations,- concentrations, ensuring consistent highperformance removal. Comparative analysis with traditional electrodialysis (ED) systems illustrates the potential of our proposed method in delivering significant energy savings and operational benefits. This investigation not only broadens the horizon of membrane separation technology but also underscores the potential of FCDIbased processes in fostering the development of more sustainable water treatment and hazardous material remediation strategies.

The Concentration Gradient Battery (CGB) has numerous advantages, such as zero pollution emissions and the use of non-toxic electrolytes, making it a promising candidate for integrating renewable energy into the power grid. The use of high-performance membranes is a necessary condition for the application of CGB, but the specific membrane characteristics that contribute to desired CGB performance have not been clearly defined. In this study, five commercial membranes were employed to investigate the relationship among membrane permeation of water and salt, stack resistance, and battery performance. The results highlighted the pivotal roles of membrane permeability and resistivity in determining the CGB performance. Among the membrane tested, Selemion, notable for its low permeability and resistivity, was found to effectively break the trade-off between current and voltage efficiency. This superior performance is attributed to its distinctive membrane properties of low water volume fraction and high fixed charge density. This study further suggested that strategies aimed at controlling membrane swelling and increasing fixed charge density hold great promise in enhancing the membrane performance in CGB application. This research provides insights into membrane selection and customization for CGB and serves as a reference for other membrane processes focused on energy conversion.

The removal of antibiotics from the environment have become a critical issue due to their toxicity and persistence. Among various approaches, microalgae-based technology has emerged as a promising, cost-effective, and eco-friendly option. Unfortunately, a systematic and quantitative analysis of the antibiotic removal efficiency by microalgae is still lacking. Therefore, this study conducted a meta-analysis including 27 peer-reviewed publications to address this gap. The study analyzed the overall antibiotic removal efficiency and influencing factors (antibiotic type, microalgae genus, temperature, hydraulic retention time (HRT), and light intensity), and identified appropriate microalgae for specific antibiotic removal, using the effect size of response ratio. Results showed that microalgae had a significant positive effect on the removal of antibiotics, and antibiotic type, microalgae genus, HRT, and light intensity significantly impacted the overall antibiotic removal efficiency. Haematococcus exhibited better removal efficacy than the commonly used Chlorella and Scenedesmus. For specific antibiotic removal, Chlamydomonas and Chlorella were recommended for macrolide antibiotic, Chlorella for beta-lactam antibiotic, and Haematococcus for sulfa antibiotic. This study offers valuable insights for future research and can help locate the most appropriate microalgae for removing specific antibiotics.

Two aromatic polyamides─poly(3,3'-dihydroxybenzidine terephthalamide) (DHTA) and poly(3,3'-dihydroxybenzidine isophthalamide) (DHIA)─are compared for their ability to remove salts from water. DHTA is linear and rigid whereas DHIA is nonlinear and semirigid. DHTA and DHIA were selected as they allow us to investigate the effect of polymer backbone geometry on salt exclusion in a non-crosslinked thin film membrane, independently of the backbone chemistry. Because of their differences in solution viscosity, spin coating parameters for DHTA and DHIA solutions were optimized separately to produce thin film composites (TFCs) with reproducible membrane properties. The resulting DHTA TFCs displayed salt rejections of 87.8% (NaCl), 97.0% (MgSO4), and 80.3% (CaCl2). In comparison, DHIA TFCs demonstrated poor salt rejections of 21.0% (NaCl), 29.3% (MgSO4), and 15.4% (CaCl2). Cross-sectional SEM images of DHTA and DHIA films reveal that DHTA has a stratified (layered) morphology whereas DHIA exhibits a dense, featureless morphology. Both DHTA and DHIA TFCs exhibit similar surface morphology, contact angle, surface charge, and water uptake. PEG rejection experiments indicate that the average pore size of DHTA TFCs is ∼2 nm while DHIA TFCs have an average pore size of ∼3 nm. Our findings illustrate that using a rigid, linear aromatic polyamide gives an active layer with a stratified morphology, uniplanar orientation, smaller pores, and higher salt rejection, whereas the nonlinear aromatic polyamide analogue results in an isotropic active layer with larger pores and lower salt rejection.

A concentration gradient battery (CGB) is an energy storage system comprised of a series of concentrated and dilute salt solution compartments, separated by ion exchange membranes (IEMs). The battery is charged by electrodialysis (ED), which increases the concentration gradient between these solutions, and discharged by reverse electrodialysis (RED), which allows these solutions to mix. In both ED and RED, water moves by osmosis from dilute to concentrated compartments, reducing the CGB faradaic and energy efficiency. A promising approach to mitigate osmosis is to use an osmotic ballast in the dilute solution to balance the osmotic pressure and reduce faradaic energy losses. The objective of this study was to investigate the impact of ballast properties (i.e., size, structure, end-group) on the faradaic and round-trip efficiency of the CGB. To accomplish this objective, we tested seven sugar and five glycol compounds as osmotic ballasts in a closed-loop cell. Results show that ballasts with high molecular weight generally resulted in higher faradaic efficiency and lower water transport compared with low molecular weight ballasts. Data also indicates that ballast with a cyclic structure (instead of linear), non-planar structure (instead of planar), and lower number of methyl end-groups led to lower water transport. Of all ballasts tested, sucrose performed best in terms of reducing non-ideal water transport (by 109%) and enhancing both faradaic and round-trip efficiencies (from 47.4% to 77.7% and 25.5% to 38.1%, respectively) compared with the non-ballasted CGB. Our results contribute to fundamental understanding of the impact of solute properties on water and small organic molecule transport in ion exchange membranes and indicate that ballasted CGBs can be further improved through development of optimized ballasts and selection of optimum membrane-ballast pairs. The improved understanding of ballast impact on CGB performance could be used for evaluation of potential ballast benefits in other membrane-based systems that may be impacted by osmosis such as the acid-base flow battery, waste heat recovery using RED, ED purification processes, osmotically assisted processes, and redox flow batteries.

Effective and sustainable recycling of valuable metals from spent lithium ion batteries (LIBs) after acid leaching are still facing challenges in hydrometallurgical process. In this study, separation of Co(II) and Li(I) from spent LIBs leaching solution was achieved by using newly developed polymer inclusion membrane electrodialysis (PIMED). Significantly high Co(II) transport flux (145.8 mu mol m(-2)s(-1)) along with high selectivity was achieved, which was much larger than those of the commercial membranes CJMA-3 and AGU, and those reported PIMs and liquid membranes. Solution purity higher than 99.9 % and 99.1 % for Li(I) and Co(II) was obtained in feed and stripping solutions, respectively. Possible transport mechanism for Co(II) was established as a fixed-site jumping mechanism allowing ions to be transported directly in a continuous pathway manner even with low current density. PIMED system exhibited excellent long-time stability in 10 repeated transport cycles. Moreover, PIMED was an energy-saving method with the lowest green-house gas (GHG) emission of 3.1 kg CO(2)e kg(-1)Li(I) in comparison with other electrochemical methods. The realization of scale-up experiments also supplies precondition for the large-scale industrial applications. This technology is a promising candidate for practicable recycling of valuable metals from LIBs with high separation performance and environmental benefits.

In order to improve the retention of amino acids in desalinating a saline stream using electrodialysis, a novel porphyrin-containing thin-film composite (TFC) cation exchange membrane was prepared by interfacial polymerization (IP) using tetraphenylporphinesulfonate (TPPS), m-phenylene diamine (MPD), and trimesoyl chloride. The separation of a single amino acid [Arginine (Arg), Lysine (Lys), Histidine (His), and Proline (Pro)] and the mixture of four from a NaCl solution was investigated. Results showed that sodium ions transported much faster than the amino acid ions due to its small molar mass and high mobility. Arg migrated much faster than Lys may attribute to its guanidine that increased the polarity of the ion, thus resulting in a higher loss degree of Arg (60%) than that of Lys (32%) in the single amino acid test. In the mixed amino acid test, a competition behavior between Arg and Lys limited their transport over membrane. The loss degree of Arg and Lys was reduced to 32.7% and 9.31% with porphyrin TFC membrane, which could be attributed to combination of the TFC dense layer and the strong electrical interaction between the charge-elevated membrane surface and the amino acids. The porphyrin TFC achieved a loss degree of total amino acids of 13.8%, which was much lower than that of pristine TFC membrane (20.2%) and based membrane (27.25%), respectively. These findings indicated that using porphyrin TFC membrane can efficiently separate salts and amino acids, and may also be beneficial for other membrane separation techniques.

Soy sauce is a common condiment that has a unique flavor, one that is derived from its rich amino acids and salts. It is known that excessive intake of high-sodium food will affect human health, causing a series of diseases such as hypertension and kidney disease. Therefore, removing sodium from the soy sauce and retaining the amino acids is desirable. In this study, electrodialysis (ED) was employed for the desalination of soy sauce using commercial ion exchange membranes (IEMs). The influence of the current density and initial pH on the desalination degree of the soy sauce was explored. Results showed that the optimal desalination condition for ED was reached at a current density of 5 mA/cm2 and pH of 5, with the desalination degree of 64% and the amino acid loss rate of 29.8%. Moreover, it was found that the loss rate of amino acids was related to the initial concentration and molecular structure. In addition, the amino acid adsorption by IEMs was explored. Results implied that the molecular weight and structure affect amino acid adsorption. This study illustrated that the ED process can successfully reduce the salt content of the soy sauce and retain most of the amino acids without compromising the original flavor.

Mitigating faradaic reactions is critical for improving charge efficiency, reducing energy consumption, and protecting electrodes from degradation during desalination in capacitive deionization (CDI). In this study, we examined the influence of recirculating flow electrodes (FEs) within their respective anode and cathode chambers [within-chamber (WC)] or across them [cross-chamber (CC)] on pH, faradaic reactions, and energy demand under constant current operation. By changing from WC to CC (without FEs), the difference in pH between the anode and cathode chambers decreased from 10 to 4.5 units. Adding FEs to CC recirculation further reduced the pH gradient between anode and cathode chambers and resulted in the most stable pH (10.4 +/- 0.08) of all treatments. We attributed the improvements in CC recirculation to faradaic consumption of anode-generated H+ at the cathode and neutralization of H+ and OH- via water formation. The capacitive behavior of FEs reduced several faradaic reactions by decreasing the whole-cell voltage. The energy consumption by the electrodes was reduced by 25% for the anode and 35% for the cathode when FEs were operated in CC instead of WC recirculation. These findings indicate that continuously recirculating FEs across the anode and cathode chambers can minimize detrimental faradaic reactions and pH changes in FE-CDI.

Global estimates of electricity generation from coastal salinity gradient energy resources rely on the underlying assumption that these gradients are spatially and temporally stable. Refining these estimates requires a better understanding of coastal variations in water properties and their impact on power production. This study investigated power output in reverse electrodialysis (RED) cells by coupling seawater samples collected from three different sites along coastal North Carolina at five different sampling dates between 2016 and 2017 with wastewater effluent from a wastewater treatment facility as the dilute solution. We found that power density did not vary substantially across the sampling dates except for one notable drop in power for a sample collected during an approaching hurricane. For all sites, power output peaked during the summer season. Using our experimental results, we developed a semi-empirical predictive model of RED power output as a function of temperature and conductivity. The model was able to predict power density within approximately 20% of the experimental power densities for the seawater samples used in this study and others in the literature. Combining our modeling approach with temporal conductivity and temperature data may help identify promising sites for coastal salinity gradient energy installations.

筛选能够降解废弃生活油脂的微生物,实现丹江口库区生活污水中废弃油脂的生物降解,减少生活油脂对库区水体的污染。以大豆油为目标污染物,先进行菌种富集和驯化,然后进行中性红平板筛选及生理生化鉴定。筛选获得了一株高效降解丹江口库区生活废弃油脂土著微生物,且具有较好的环境适应性和应用潜力。经鉴定,该微生物与Proteus mirabilis最为接近,命名为Proteus mirabilis NY-201801。5%（体积分数）油脂初始浓度,接种量10%,p H值7. 0,在35℃、150 r/min下培养36 h,Proteus mirabilis NY-201801对油脂的降解率可以达到92%。同时,在库区最高水温的条件下,对5%油脂的降解率也可以达到50%。为实现库区废弃生活油脂的生物降解奠定了坚实的基础。

Capacitive neutralization dialysis energy (CNDE) is proposed as a novel energy-harvesting technique that is able to utilize waste acid and alkaline solutions to produce electrical energy. CNDE is a modification based on neutralization dialysis. It was found that a higher NaCl concentration led to a higher open-circuit potential when the concentrations of acid and alkaline solutions were fixed. Upon closing of the circuit, the membrane potential was used as a driving force to move counter ions into the electrical double layers at the electrode-liquid interface, thereby creating an ionic current. Correspondingly, in the external circuit, electrons flow through an external resistor from one electrode to the other, thereby generating electrical energy directly. The influence of external resistances was studied to achieve greater energy extraction, with the maximum output of 110 mW/m2 obtained by employing an external resistance of 5 Ω together with the AC-coated electrode.

Capacitive flow electrode systems that generate electricity from salinity gradients are limited by low power densities, inefficient electrical current collection, and complex system operation. We show here the proof-of-concept that a single reverse electrodialysis cell using continuously recirculated activated carbon flow electrodes can generate uninterrupted electricity from an artificial sea/river water gradient. Power densities reached 61 +/- 5.7 mW m(-2) (normalized to total membrane surface area) and current densities 2.4 +/- 0.13 A m(-2) when a 10% by weight carbon loading was used with graphite plate current collectors. Using high-surface area graphite brush current collectors, maximum power densities increased more than 320% to 260 +/- 8.7 mW m(-2) and maximum current densities more than 400% to 14 +/- 0.59 A m(-2). The performance improvements were attributed to a more than 80% decrease in electrode resistances when brushes were used instead of plates. A control static capacitive electrode system obtained slightly higher average power densities (290 +/- 8.7 mW m(-2)), but could not produce it continuously, highlighting the operational advantage of the recirculated flow electrode design. (C) 2017 Elsevier B.V. All rights reserved.