Ion Exchange Technology Research Articles

Ion exchange columns. A promising technology for nitrogen and phosphorus recovery in the main line of a wastewater treatment plant

Anaerobic membrane bioreactor (AnMBR) technology has great advantages for treating urban wastewaters, but, when irrigation cannot be applied and the effluent is discharged in a sensitive zone, a post-treatment of this effluent is needed for nitrogen and phosphorus removal. Under this scenario, ion exchange processes represent one of the most promising technologies for treating this effluent. Ion exchange technology allows to meet discharge limits and to recover these nutrients in a highly concentrated stream. In this work, the technical feasibility of using a commercial resin for phosphorus recovery and a natural zeolite (clinoptilolite) for nitrogen recovery was evaluated. Purolite FerrIX A33E resin removed phosphate from the AnMBR permeate within 500 Bed Volumes (BVs) with a maximum adsorption capacity (qmax) of 2,1 mg P-PO4/g resin. Regeneration of the resin (2% NaOH 2% NaCl) recovered over 95% of the phosphorous retained, achieving a concentration of 316,7 mg P-PO4/L in the regeneration solution. In the absence of a long-term study, the resin showed a stable adsorption capacity during 16 cycles of saturation-regeneration. Clinoptilolite removed nitrogen within 139 BVs obtaining a qmax of 3,68 mg N-NH4/g zeolite. 97 % of the retained N-NH4 was recovered in the regeneration stage (0,8% NaOH) with an average concentration of 577 mg N-NH4/L. Continuous exposure of the zeolite to alkaline solutions led to reduction of 50% of the adsorption capacity after 17 cycles.

Polymer-Based Extracting Materials in the Green Recycling of Rare Earth Elements: A Review.

Rare earth elements (REEs) are becoming increasingly important in the development of modern and green energy technologies with the demand for REEs predicted to grow in the foreseeable future. The importance of REEs lies in their unique physiochemical properties, which cannot be reproduced using other elements. REEs are sourced through mining, with global exploration of additional commercially viable mining sites still ongoing. However, there is a growing need for recycling of REEs due to the current supply of REEs not matching the growing demand, the environmental impact of REE mining and processing (the so-called "balance problem"), and the generation of large volumes of harmful electronic waste (e-waste). Industrial REE processing is mainly carried out by hydrometallurgy processes, particularly solvent extraction (SX) and ion exchange (IX) technologies. However, these methods have a significant environmental impact due to their intensive use of harmful and nonsustainable reagents. This Review highlights the development of approaches involving polymer-based extracting materials for REE manufacturing as more sustainable alternatives to current industrial REE processing methods. These materials include supported liquid membranes (SLMs), solvent impregnated resins (SIRs), macro and micro capsules, polymer inclusion membranes (PIMs), and micro polymer inclusion beads (μPIBs). Polymer-based extracting materials have the advantage of more economical regent usage while applying the same extractants used in commercial SX, enabling applications analogous to the current industrial process. These materials can be fabricated by a variety of methods in a diverse range of physical formats, with the advantages and disadvantages of each material type described and discussed in this Review along with their applications to REE processing, including e-waste recycling and mineral processing.

Pengurangan Kandungan Total Dissolved Solid (TDS), Konduktivitas dan Natural Organic Matter (NOM) pada Air Baku Bendungan Jatiluhur Menggunakan Kombinasi Membran dan Ion Exchange

The escalating demand for high-quality water in industrial applications has prompted the adoption of demineralization processes as an effective solution to eliminate disruptive minerals and ions. Water, vital for process and cooling needs, must meet strict standards to avoid issues like corrosion and heavy metal pollution. Contaminants pose risks, necessitating careful attention. This study assesses demineral water requirements based on Total Dissolved Solids (TDS), conductivity, and Natural Organic Matter (NOM). Examining membrane and ion exchange technologies, including Reverse Osmosis (RO), Ultrafiltration (UF), and ion exchange resins independently and in combination, the study also explores the impact of flow rate on TDS, conductivity, and NOM. Additionally, it investigates the effect of flow rate on sampling locations at the Jatiluhur Dam. Research results highlight the effectiveness of a combined RO and resin approach, achieving an 89% reduction in TDS, 88% in conductivity, and complete NOM removal.

Life cycle assessment and techno-economic analysis of nanotechnology-based wastewater treatment: Status, challenges and future prospectives

BackgroundWater pollution is a pressing concern stemming from both natural and anthropogenic activities. The challenges associated with water treatment technologies are adsorption (fouling and corrosion of the adsorbent), flocculation (increased sludge generation and high operation cost), ion exchange (high cost and improper ion removal), chemical precipitation (sludge generation), and membrane technologies (membrane fouling and storage). These technologies have been overstretched and struggle to meet increasingly stringent water quality standards. More recent progress has been made in using nanotechnology for wastewater treatment. Nano-technology offers several advantages over traditional technologies. Many nano-based technologies support reuse, require less space, produce fewer toxic intermediates, and are adaptable to support the emerging concept of decentralized water treatment. An essential aspect of this review is a detailed techno-economic analysis, assessing the long-term viability of nanotechnology-based wastewater treatment methods from an economic standpoint. MethodsThis review outlines the current state of nanotechnology in wastewater treatment, addressing environmental and economic aspects, challenges, and future potential. Significant findingsUnderstanding the sustainability and feasibility of these innovative technologies is crucial for their successful integration into wastewater treatment practices, ensuring a more effective and environmentally friendly approach to water remediation.

Determination of technogenic risks when using various water purification technologies

In modern conditions, ensuring the reliability and safety of water supply systems is a primary task for the industrial economy and the safety of life of the population of Ukraine. Constant bombing and damage to critical infrastructure facilities, including water management facilities, endangers the stability and quality of the country's water resources. In this context, conducting research on the identification of man-made risks in water treatment systems using various technologies, as well as developing strategies to increase the reliability and safety of operation of water supply systems are becoming relevant for the industrial sector of Ukraine. In order to increase the reliability of water treatment units and their operational safety, man-made risks were investigated when using ion exchange, electrodialysis, and water distillation technologies at thermal power plants. It is shown that during normal operation of the ion-exchange water purification system with an average productivity of 400 m3/h, in the case of frequent changes in the concentration of salts at the inlet, the risk of receiving underpurified water is 0.0783. This value must be taken into account for the assessment of economic and social-ecological risks, since it exceeds the generally accepted value of 0.01. When using electrodialysis water purification and frequent changes in the concentration of salts at the inlet, the risk of receiving underpurified water is 0.0271. This value is also greater than 0.01 risk accepted as acceptable. The water distillation technology has enough margin to compensate for any deviations in the purification process and gives a very low risk. However, the distillation process is more effective in removing only soluble impurities, while in the case of suspended substances, in particular of organic origin, there is a risk of exceeding the limit of 0.01.

Separation process for the production of high-purity antimony and bismuth oxides from copper electrorefining circuit wastes: The relevance of the redox control

The copper pyrometallurgical industry faces challenges in maintaining copper purity due to increasing impurities in primary resources. Notably, Sb, Bi, and As can form insoluble compounds, compromising copper purity in electrorefining units. To address this, ion-exchange (IX) technology is employed to continually treat copper electrolyte of the electrorefining stage, removing Sb and Bi and ensuring a high copper purity (99.99 %). Upon IX resin saturation, regeneration with 6 M HCl produces a concentrated eluate containing Sb, Bi (7–14 g/L each), and As (1–4 g/L). Currently, lime treatment removes these impurities without valorization, which produces large volumes of waste containing As, Sb and Bi. Recognizing Sb and Bi as critical raw materials, this study aims to develop a valorization route, with the objective of recovering both elements free of As using selective precipitation. Pre-treating the eluate to reduce As and Sb to the (+III) state prevented mixed mineral phases, enabling the recovery of high purity Sb4O5Cl2(s) and BiOCl(s) containing low contents of impurities as As. Further improvement could be achieved with the conversion of the oxychlorides to the oxide forms (M2O3(s)) in alkaline media for potential commercial use. This research contributes to sustainable metal recovery and addresses toxicity concerns associated with As, paving the way for enhanced environmental and economic outcomes in the copper industry.

Highly Sensitive On-Chip Grating-Based Optical Sensor on Glass Substrate: Cost-Effective Design

This paper presents a novel on-chip optical sensing system using ion exchange technology and phase-shifted Bragg grating design. The sensor geometry has been optimized using a finite difference time domain (FDTD) solver to achieve maximum sensitivity and figure of merit (FOM). The proposed design offers high sensitivity to changes in refractive index and low fabrication costs. The ion exchange process used to create the sensor allows for precise refractive index control, optimizing the sensor’s sensitivity and FOM. A graded-index waveguide and a phase-shifted Bragg grating structure also contribute to the sensor’s high sensitivity. The proposed sensor design was tested for water-based sensing applications, achieving a FOM of 227.63 and a 343.1 nm/RIU sensitivity. These values are significantly higher than those reported for other Bragg grating sensors, highlighting the potential of the proposed design for high-performance sensing applications. The sensor’s high sensitivity and low fabrication costs make it a promising technology for future sensing and monitoring applications.

Field installation of ion exchange technology for purification of retention reservoirs from nitrogen-based nutrient contamination

N- and P-nutrient contamination is recognised as one of the key factors that reduces the quality of water. In this context, a new water purification installation was set up in the Turawa reservoir (district Opole, Poland). The process involves ion exchange columns operated in twin configuration: once one column filtrates water, the second one regenerates. The installation design is modular, and the devices are placed in a container station. This enables efficient water purification in various locations and further offers scalability. The research focused on the design and optimization of the installation, as well as environmental assessment of how the installation influenced the quality of water. This technology afforded a decrease in the concentrations of NO3− ions, suggesting an apparent selectivity. The removal of NO3− reached 97 % and was maintained for over 100 m3 of purified water. In turn, the removal of PO43− was not effective; however, the collected data allowed the installation design to be adjusted such that the cascade arrangement of ion exchange columns can be considered. The technology was assessed over all four seasons in the two-year test period (2020−2021). This revealed that environmental factors, such as season, air temperature, wind, and relative humidity, influence the operation of the installation. The installation functions optimally in spring with an average air temperature of 11–20 °C, high relative humidity of 90–100 %, and an average wind speed of 2 m/ s. The implementation of the technique could easily broaden the perspectives of Earth's water preservation and sustainability.

Modelling and optimization of Li+ extraction from brine with high Mg/Li ratio by electrochemically switched ion exchange considering thermodynamics and dynamics simultaneously

Electrochemically switched ion exchange (ESIX) technology has been proven to be an efficient and environmental-friendly method for extracting Li+ from brine lakes. To deeply understand and mathematically express the underlying physical process of Li+ extraction in ESIX, a model is developed to describe Li+ extraction from brine lakes with a high Mg/Li mass ratio (500:1) by ESIX with an electrode coated with λ-MnO2 film. The kinetics and thermodynamics of the Li+ extraction process is considered simultaneously by coupling the Frumkin-Bulter-Volmer theory modified by electroactive site concentration with a modified Gouy-Chapman-Stern model. The local sensitivity analysis indicates that the performance of ESIX in Li+ adsorption is greatly influenced by cell voltage, film mass, and Stern capacitance of carbon black film, whereas these parameters have little effect on Mg2+ adsorption. The individual parameter analysis elucidates that the mass and Stern capacitance of carbon black film can regulate the potential drop distributions in different regions of ESIX system, resulting in a maximum Li+ extraction efficiency of 90.22 % due to the increased driving force in the faradic reaction and reduced charge transfer resistance. The optimization of combined parameters indicates that the optimum operation can be achieved at the conditions with a cell voltage ranging between 1.0 and 1.2 V, a Stern layer capacitance with electric double layer volume for carbon black film of 5.4 × 107 F/L, and an initial Li+ content of the treatment solution: carbon black film: λ-MnO2 film mass ratio of 0.1 kg: 9 kg: 8 kg.

Study of technological parameters of ion exchange resins and technology of recultivation of off-balance uranium-containing dumps

Study of technological parameters of ion exchange resins and technology of recultivation of off-balance uranium-containing dumps

An energy efficient hybrid membrane technique for the removal of toxic metals from aquatic environment

Electrodeionization (EDI), integrates electrodialysis (ED) and ion exchange (IE) technology. The purpose of this study is to utilize an EDI unit for eliminating copper from wastewater. This process was demonstrated using a three-compartment system, comprising a central compartment filled with a cation exchange resin (CER), separated from the anodic and cathodic chambers by two cationic exchange membranes (CEM), with the anode and cathode placed in the anodic and cathodic chambers, respectively. Purolite C 160 was used to showcase how operational variables, such as initial concentration, contact duration, resin dosage, and temperature, were optimized for the most effective copper removal during batch mode operation. The optimized conditions were an initial concentration of 100 ppm, a Purolite C dose of 0.5 g/L, a contact time of 1 h, and a pH of 8. At an initial copper concentration of 100 ppm and a supply voltage in the range of 10 to 25 V, the highest copper removal achieved was close to 99.98 per cent. For this study, copper was eliminated in the described experiments up to 99.98%, with energy consumption in the EDI unit varying between 3.87 and 25.29 kWh per kg of removed copper.

Recovery of metal ion resources from waste lithium batteries by in situ electro-leaching coupled with electrochemically switched ion exchange

A new green pathway of in situ electro-leaching coupled with electrochemically switched ion exchange (EL-ESIX) technology was developed for the separation and recovery of valuable metal ions from waste lithium batteries. By using the in situ electro-leaching, the leaching rates of Li+ and Co2+ from the prepared LiCoO2 film electrodes reached 100 % and 93.30 %, respectively, under the combined effect of the acidic microenvironment formed by the anodic electrolytic water and electrostatic repulsion. Subsequently, the Li+ in the electrolyte was further extracted by an electrochemically switched ion exchange (ESIX) process using LiMn2O4 as the film electrode, and Li+ was further enriched in the eluate by a cyclic adsorption and desorption process. The results indicate that the in situ electro-leaching has significant advantages over powder leaching, and for the recycling of waste lithium batteries, the final lithium recovery rate reached 94.51 % by using this in situ EL-ESIX technology.

Research in Industrial Use of Ion Exchange and Simulation

We investigated the industrial use of ion exchange technology as well as the modeling of fixed bed, multicomponent ion exchange processes. In this paper we report on both fields of this research. We have developed a complex technology for the selective separation of the long-live radionuclides and the partial recycling of boric acid from radioactive evaporator bottom residue. A wastewater treatment system has been developed by using a cesium-selective inorganic ion exchanger. The selective separation of 137Cs, 134Cs from high salt concentration and strongly alkaline evaporator bottom residue in Paks NPP has a volume reduction factor of about 3500–6500 at the value of the decontamination factor DF > 100, for the samples of four evaporator bottom residue tanks of the NPP. Some important classes of ion exchangers do possess uniform internal pore structures and bring all parts of the solíd structure into much closer contact with the liquid. Such materials are porous organic resins. For these types of exchangers, we have modified Mansour's multicomponent adsorption model and developed a computer program to describe multicomponent breakthrough, cocurrent, and counter-current elution curves for ion exchangers. In addition, we have developed a subroutine for the calculation of multicomponent ion exchange kinetics according to Nernst-Planck equation and successfully tested it. This subroutine will be added to the multicomponent ion exchange breakthrough and elution simulation program to have a real multicomponent ion exchange simulation program. In this paper we report about these research results too.

Chromium (VI) adsorption from steel industry wastewater using biomass and agro-based adsorbents: A Review

In recent years, increased steel production has resulted in an increased release of Cr (VI) effluent from electroplating processes. The current conventional technologies for Cr (VI) removal, for instance, chemical precipitation, ion exchange, membranes, and electrochemical technologies, have proven to be expensive and not eco-friendly. Adsorption using biomass or agro-based adsorbents has been demonstrated to be an eco-friendly method. In this study, the potential of several biomass and agro-based adsorbents for Cr (VI) removal from steel industry wastewater has been reviewed. The application of adsorption parameters, isotherms, and kinetic models has also been reviewed. The study review reveals that the maximum adsorption of Cr (VI) ions from wastewater was dependent on the pH, temperature, contact time, type of adsorbent material, and initial metal concentration. The literature review demonstrated that maximum Cr (VI) adsorption efficiency ranged from 90–100%, with optimum pH, contact time, and temperature ranging from 2–5, 30-180 min, and 25–30 °C, respectively. The equilibrium adsorption data was best described by the Langmuir and Freundlich isotherms and the pseudo-second-order kinetic model. The thermodynamic studies revealed that the adsorption process was spontaneous and endothermic. It has been found that biomass and agro-based adsorbents are potentially eco-friendly alternatives for Cr (VI) removal from industrial wastewater. However, several gaps have been identified to improve the Cr (VI) removal efficiency, spent adsorbent reuse and safe disposal, optimisation, and commercial application of agro-based adsorbents.

Current technologies for heavy metal removal from food and environmental resources.

Exposure to heavy metals in water and food poses a significant threat to human well-being, necessitating the efficient removal of these contaminants. The process of urban development exacerbates heavy metal pollution, thereby increasing risks to both human health and ecosystems. Heavy metals have the capacity to enter the food chain, undergo bioaccumulation and magnify, ultimately resulting in adverse effects on human health. Therefore, implementing effective pollution control measures and adopting sustainable practices are crucial for mitigating exposure and associated health risks. Various innovative approaches, including adsorption, ion exchange, and electrochemical technology, are currently being actively investigated to cope with the issue of heavy metal contamination. These innovative methods offer benefits such as efficient recycling, cost-effectiveness and environmental friendliness. In this review, we summarize recent advances for removing heavy metals from water, soil and food, providing valuable guidance for environmental engineers and researchers seeking to address contamination challenges.

Membrane Functionalization Approaches toward Per- and Polyfluoroalkyl Substances and Selected Metal Ion Separations.

Adsorption and ion exchange technologies are two of the most widely used approaches to separate pollutants from water; however, their intrinsic diffusion limitations continue to be a challenge. Pore functionalized membranes are a promising technology that can help overcome these challenges, but the extents of their competitive benefits and broad applicability have not been systematically evaluated. Herein, three types of adsorptive/ion exchange (IX) polymers containing strong/weak acid, strong base, and iron-chitosan complex groups were synthesized in the pores and partially on the surface of microfiltration (MF) membranes and tested for the removal of organic and inorganic cations and anions from water, including arsenic, per- and polyfluoroalkyl substances (PFAS), and calcium (hardness). When directly compared with beads (0.5-6 mm) and crushed resins (0.05 mm), adsorptive/IX pore-functionalized membranes demonstrated an increased relative sorption capacity, up to 2 orders of magnitude faster kinetics and the ability to regenerate up to 70-100% of their capacity while concentrating the initial solution concentration up to 12 times. The simple and versatile synthesis approach used to functionalize membranes, notably independent of the polymer type of the MF membrane, utilized pores throughout the entire cross section of the membrane to immobilize the polymers that contain the functional groups. Utilizing the pore volume of commercial membranes (6-112 mL/m2), the scientific weight capacity of the polymer (3.1-11.5 mequiv/g), and the synthesis conditions (e.g., monomer concentration), the theoretical adsorption/IX capacities per area of the membranes were calculated to be as high as 550 mequiv/m2, substantially higher than the 175 mequiv/m2 value needed to compete with commercially available IX resins. This work therefore shows that pore functionalized membranes are a promising path to tackle water contamination challenges, lowering separation diffusion limitations.

A comparative exergy-based assessment of direct air capture technologies

The 6th Assessment of the IPCC underlined the need for urgent measures for carbon dioxide removal from the atmosphere, so as to meet the 1.5 °C goal by the end of this century. One option to achieve this is direct air capture (DAC) technologies. This work assesses the thermodynamic performances of different categories of DAC technologies, i.e., adsorption-based, absorption-based, ion exchange, and electrochemical. An exergy analysis is performed on the DAC processes in each category to identify hotspots for efficiency loss within the system. The results show that the consumption of materials is responsible for 5–40% of the exergy consumption of the most-developed DAC processes. Despite their greater use of materials compared to absorption-based processes, adsorption-based processes, together with ion exchange technologies, have the highest exergy efficiencies of the DAC technologies investigated. Moreover, the results highlight the importance of limiting material consumption and electrifying large-scale DAC plants, which cannot run exclusively on waste heat from industrial processes.

Buried Optical Waveguide in Photo-Thermo-Refractive Glass by Ion Exchange Technology

To realize application of functional material Photo-Thermo-Refractive (PTR) glass for integrated photonic device production, PTR glass material is fabricated and employed as matrix material for planar optical waveguide manufacturing. Buried optical waveguide, with a core dimension of 8.7 μm × 9.0 μm (width by height), and its front edge located at approximately 12.5 μm underneath the glass substrate surface, is obtained by using thermal ion exchange (TIE) and subsequent field-assisted ion migration (FAIM). Transmission loss of these waveguides can be reduced to a value as low as 0.08 dB/cm at the operating wavelength of 1550 nm, and the coupling loss to standard single-mode-fiber is measured to be 0.47 dB/facet, demonstrating the feasibility of low-loss integrated photonic devices fabrication on PTR glass materials by ion exchange technology.

Impact of nano-Al2O3 coating on the dielectric properties and High-Frequency surface electrical strength of the polyimide films

Polyimide (PI) films used for inter-turn insulation of power electronic transformer (PET) are prone to premature insulation failure. Using ion-exchange technology to modify the surface of PI films effectively improves its high-frequency (HF) insulation strength. In this paper, the HF discharge characteristics of PI films were studied coated a nano-Al2O3 layer. The experimental results illustrate that the introduction of nano-Al2O3 coating can effectively improve the HF surface insulation strength of modified PIs, in which the maximum discharge lifetime is increased to 5.6 times of the pristine PI, and the creeping flashover voltage raised from the initial 6.34 kV to 11.98 kV, an increase of 88.96%. The enhanced mechanism of HF insulation performance of modified PIs is as follows: On the one hand, formed the functional nano-Al2O3 coating improves the thermal management ability and the inorganic–organic phase structure of the modified PIs, which is effective in reducing the temperature rise of materials. On the other hand, the introduction of the nano-Al2O3 coating increases the density of the shallow trap, increasing the surface conductivity of modified PIs, and hindering the development of HF surface discharge. This paper offers a prospective strategy for polyimide dielectrics with superior HF insulation performance.

An Electroactive BiOBr/PVDF/CB Film Electrode for Electrochemical Extraction of Bromine Ions from Brines

An electroactive bismuth oxybromide/polyvinylidene difluoride/carbon black(BiOBr/PVDF/CB) composite film electrode was fabricated that had a bromide ion trap (Br–-trap) effect obtained by prereleasing of Br– under reduction potential. The Br–-trap BiOBr/PVDF/CB film electrode was used for the selective extraction of Br– from salt lake brine by electrochemically switched ion exchange (ESIX) technology. Moreover, an industrially scalable ESIX pilot system was designed and the effects of different process parameters were investigated. In the ESIX system, the obtained film electrode exhibited efficient adsorption quantity, and remarkable selectivity owing to its special ion trap effect. The extraction capacity of Br– reached 67.10 mg g–1 with the separation factors of 2.06 and 7.13 for Br–/Cl– and Br–/NO3–, respectively, and the desorption efficiency of the film electrode remained at 95.4% after seven repeated cycles. It manifested that the pilot system with the Br–-trap BiOBr/PVDF/CB film electrode is expected to provide a novel direction for practical industrial Br– extraction.