Current Separation Methods Research Articles

Three-chamber electrochemical reactor for selective lithium extraction from brine

Efficient lithium recovery from geothermal brines is crucial for the battery industry. Current electrochemical separation methods struggle with the simultaneous presence of Na+, K+, Mg2+, and Ca2+ because these cations are similar to Li+, making it challenging to separate effectively. We address these challenges with a three-chamber reactor featuring a polymer porous solid electrolyte in the middle layer. This design improves the transference number of Li+ (tLi+) by 2.1 times compared to the two-chamber reactor and also reduces the chlorine evolution reaction, a common side reaction in electrochemical lithium extraction, to only 6.4% in Faradaic Efficiency. Employing a lithium-ion conductive glass ceramic (LICGC) membrane, the reactor achieved high tLi+ of 97.5% in LiOH production from simulated brine, while the concentrations of Na+ K+, Mg2+, and Ca2+ are below the detection limit. Electrochemical experiments and surface analysis elucidated the cation transport mechanism, highlighting the impact of Na+ on Li+ migration at the LICGC interface.

Multi-category sorting of plastic waste using Swin Transformer: A vision-based approach

Sorting out plastic waste (PW) from municipal solid waste (MSW) by material type is crucial for reutilization and pollution reduction. However, current automatic separation methods are costly and inefficient, necessitating an advanced sorting process to ensure high feedstock purity. This study introduces a Swin Transformer-based model for effectively detecting PW in real-world MSW streams, leveraging both morphological and material properties. And, a dataset comprising 3560 optical images and infrared spectra data was created to support this task. This vision-based system can localize and classify PW into five categories: polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polystyrene (PS). Performance evaluations reveal an accuracy rate of 99.75% and a mean Average Precision (mAP50) exceeding 91%. Compared to popular convolutional neural network (CNN)-based models, this well-trained Swin Transformer-based model offers enhanced convenience and performance in five-category PW detection task, maintaining a mAP50 over 80% in the real-life deployment. The model's effectiveness is further supported by visualization of detection results on MSW streams and principal component analysis of classification scores. These results demonstrate the system's significant effectiveness in both lab-scale and real-life conditions, aligning with global regulations and strategies that promote innovative technologies for plastic recycling, thereby contributing to the development of a sustainable circular economy.

Chemistry of Antimony in Radiopharmaceutical Development: Unlocking the Theranostic Potential of Sb Isotopes.

Antimony-119 (119Sb) holds promise for radiopharmaceutical therapy (RPT), emitting short-range Auger and conversion electrons that can deliver cytotoxic radiation on a cellular level. While it has high promise theoretically, experimental validation is necessary for 119Sb in vivo applications. Current 119Sb production and separation methods face robustness and compatibility challenges in radiopharmaceutical synthesis. Limited progress in chelator development hampers targeted experiments with 119Sb. This review compiles literature on the toxicological, biodistribution and redox properties of Sb, along with existing Sb complexes, evaluating their suitability for radiopharmaceuticals. Sb(III) is suggested as the preferred oxidation state for radiopharmaceutical elaboration due to its stability in vivo and lack of skeletal uptake. While Sb complexes with both hard and soft donor atoms can be achieved, Sb thiol complexes offer enhanced stability and compatibility with the desired Sb(III) oxidation state. For 119Sb to find application in RPT, scientists need to make discoveries and advancements in the areas of isotope production, and radiometal chelation. This review aims to guide future research towards harnessing the therapeutic potential of 119Sb in RPT.

Research on Magnetic Field of Permanent Magnet Rolls Arranged Periodically in Circumferential—Axial Direction

The separation of non-magnetic non-ferrous metals such as copper and aluminum from scrapped automobiles is a critical area of research due to the increasing number of end-of-life vehicles. Traditional eddy current separation methods have limitations, particularly in handling large-sized broken copper and aluminum parts. This paper proposes a novel magnetic roller model featuring a circumferential–axial periodic arrangement of permanent magnets. This study explores the external magnetic field distribution of this new roller design by constructing an equivalent current model, solving magnetic scalar potential equations, and employing simulation tools. The findings indicate that the new magnet array enhances both the magnetic field strength and the range of the external magnetic field, leading to improved separation efficiency of large-sized metal fragments. The results provide a theoretical basis for advancing the separation technology of large-sized broken copper and aluminum parts in scrapped automobiles, offering potential improvements in the recycling of non-ferrous metals from end-of-life vehicles.

A method for separating tonoplast from wheat

Vacuoles account for 90% of plant cell volume and play important roles in maintaining osmotic pressure, storing metabolites and lysosomes, compartmentalizing harmful ions, and storing and reusing minerals. These functions closely relay on the ion channels and transporters located on the tonoplast. The separation of intact vacuoles from plant cells is the key technology utilized in the study of tonoplast-located ion channels and transporters. However, the current vacuole separation methods are available for Arabidopsis and some other dicotyledons but are lacking for monocot crops. In this study, we established a new method for the vacuole separation from wheat mesophyll cells and investigated the transmembrane proton flux of tonoplasts with non-invasive micro-test technology (NMT). Moreover, our study provides a technology for the study of vacuole functions in monocot crops.

The recycling and utilization of new energy batteries

As the main energy storage component of new energy vehicles, the retirement tide of power batteries is coming. The large-scale retirement of power batteries has brought huge benefits to the treatment of power batteries challenge. From the aspects of environment, resources and economy, the significance of power battery recycling is expounded, and the current status of power battery recycling is analyzed. It is aimed at strengthening new energy vehicles power battery recycling, from the aspects of improving laws and regulations, improving the recycling system and improving recycling technology, put forward countermeasures and suggestions. At present, the main technologies are mechanical separation technology, pyrolysis technology and wet extraction technology. Mechanical separation technology mainly uses vibration separation, eddy current separation and electrostatic separation methods to separate different substances in the battery. Pyrolysis technology refers to the heating of waste to a certain temperature in an oxygen-free or low-oxygen environment to decompose organic matter, gas, liquid and solid products. The pyrolysis technology method mainly recovers heavy metals such as nickel and zinc, and the recovery efficiency is high. However, air participation in the operation is easy to cause secondary pollution. Wet extraction technology mainly extracts valuable materials and valuable heavy metals through sorting and sorting, shelling, dissolving in acid and alkali solutions, extraction and ion exchange methods. This technology has a wide range of applications, high recycling rate and little impact on the environment, and is currently one of the mainstream technologies in the field of new energy vehicle battery recycling. However, the process is complex and lengthy, and the recovery of electrolyte and leaching residue is easy to cause secondary pollution, and the recovery cost is high.

Separation of trace amount of nickel from cobalt sulphate solutions using a synergistic solvent extraction system consisting of dinonylnaphthalene sulfonic acid (DNNSA) and decyl 4-picolinate (4PC)

The current methods for separation of nickel from cobalt sulphate solutions have drawbacks of long flowsheets, release of large volumes of wastewater and incomplete separation of two metals. A synergistic solvent extraction (SSX) system consisting of dinonylnaphthalene sulfonic acid (DNNSA) and decyl 4-picolinate (4PC) is proposed in this work to extract nickel from cobalt sulphate solutions selectively. The extraction of nickel reached 99.7% after five-stage counter current extraction with an A/O volume ratio of 1/6 at 30 °C, resulting in a large increase of Co/Ni mass ratio to 25,700 in raffinate from 56 in feed. The loaded organic phase can be easily stripped using a dilute H2SO4 solution. Application of this process in industry is expected to make an important impact on the production of high-purity cobalt sulphate solutions and to deliver economic benefits.

Vortex sorting of rare particles/cells in microcavities: A review.

Microfluidics or lab-on-a-chip technology has shown great potential for the separation of target particles/cells from heterogeneous solutions. Among current separation methods, vortex sorting of particles/cells in microcavities is a highly effective method for trapping and isolating rare target cells, such as circulating tumor cells, from flowing samples. By utilizing fluid forces and inertial particle effects, this passive method offers advantages such as label-free operation, high throughput, and high concentration. This paper reviews the fundamental research on the mechanisms of focusing, trapping, and holding of particles in this method, designs of novel microcavities, as well as its applications. We also summarize the challenges and prospects of this technique with the hope to promote its applications in medical and biological research.

Light-Driven Purification of Progesterone from Steroid Mixtures Using a Photoresponsive Metal-Organic Capsule.

Chemical separations are expensive, consuming 10-15% of humanity's global energy budget. Many current separation methods employ thermal energy for distillation, often through the combustion of carbon-containing fuels, or extractions and crystallizations from organic solvents, which must then be discarded or redistilled, with a substantial energetic cost. The direct use of renewable energy sources, such as light, could enable the development of novel separations processes, as is required for the transition away from fossil fuel use. Metal-organic capsules, which can selectively bind molecules from mixtures, can provide the foundation for these novel separations processes. Here we report a tetrahedral metal-organic capsule bearing light-responsive diazo moieties around its metal-ion vertices. This capsule can be used to selectively separate progesterone from a mixture of steroids in a process driven by visible light energy. Our process combines biphasic extraction and selective binding of progesterone with the light-driven release of this molecule in purified form. Ultimately, our process might be adapted to the purifications of the many other fine chemical products that are bound selectively by capsules.

Bioseparation of rare earth elements and high value-added biomaterials applications

Rare earth elements (REEs) are a group of critical minerals and extensively employed in new material manufacturing. However, separation of lanthanides is difficult because of their similar chemical natures. Current lanthanide leaching and separation methods require hazardous compounds, resulting in severe environmental concerns. Bioprocessing of lanthanides offers an emerging class of tools for REE separation due to mild leaching conditions and highly selective separation scenarios. In the course of biopreparation, engineered microbes not only dissolve REEs from ores but also allow for selective separation of the lanthanides. In this review, we present an overview of recent advances in microbes and proteins used for the biomanufacturing of lanthanides and discuss high value-added applications of REE-derived biomaterials. We begin by introducing the fundamental interactions between natural microbes and REEs. Then we discuss the rational design of chassis microbes for bioleaching and biosorption. We also highlight the investigations on REE binding proteins and their applications in the synthesis of high value-added biomaterials. Finally, future opportunities and challenges for the development of next generation lanthanide-binding biological systems are discussed.

Precipitation of manganese by ozone from hydrometallurgical recycling process of lithium-ion batteries

The increasing demand for clean transportation facilities has significantly contributed to the rise in electric vehicle sales. However, it needs the development of effective strategies for battery disposal. Regarding the circular economy, the recovery of materials from these batteries is crucial for the supply chain. The current purification methods for manganese separation from lithium nickel manganese cobalt oxide (NMC) battery recycling present some limitations and low selectivity. In this work, a novel approach for manganese recovery from leach solution of NMC battery recycling is presented. The use of ozone permits the recovery of manganese without adding any other element to the system. With the right conditions, settled through simulations, the ozonation technique has proven to be highly effective, enabling the recovery of 100% with manganese 97.6% purity. Optimal conditions for this process were determined, as reaction time of 405 min, oxygen flow rate 1 L/min, and 8.9 g of ozone to oxidize 3.6 g of Mn.

Exosome Precipitation by Ionic Strength Modulation: ExoPRISM.

Extracellular vesicles (EVs) are emerging as crucial materials for precision theragnostic applications. However, current separation methods are time-consuming, costly, and not scalable and deliver limited yields or purity. Here, we present EV precipitation by ionic strength modulation (ExoPRISM), a simple, low-cost, user-friendly, and readily adaptable approach for separating EVs in high yields without compromising their biological functions. Adding an electrolyte solution to blood plasma in small increments generates the sequential precipitation of proteins and EVs, allowing for fractional separation of EVs using low-speed centrifugation. The coprecipitated electrolytes are easily washed away, and the entire EV separation and washing process takes less than an hour. This approach successfully separates EVs from a broad range of volumes and types of biological fluids, including culture medium, urine, plasma, and serum, showing promise as a robust tool for next-generation liquid biopsies and regenerative medicine.

Rapid Isolation of Low-Level Carbapenem-Resistant E. coli from Water and Foods Using Glycan-Coated Magnetic Nanoparticles.

Carbapenem-resistant Enterobacterales (CRE) are one of the major global issues needing attention. Among them, carbapenemase-producing (CP) E. coli strains are commonly found in clinical and biological samples. Rapid and cost-effective detection of such strains is critical in minimizing their deleterious impact. While promising progress is being made in rapid detection platforms, separation and enrichment of bacteria are required to ensure the detection of low bacterial counts. The current separation methods, such as centrifugation, filtration, electrophoresis, and immunomagnetic separation, are often tedious, expensive, or ineffective for clinical and biological samples. Further, the extraction and concentration of antimicrobial-resistant bacteria (ARB) are not well documented. Thus, this study assessed the applicability of cost-effective glycan-coated magnetic nanoparticles (gMNPs) for simple and rapid extraction of CP E. coli. The study included two resistant (R)strains: Klebsiella pneumoniae carbapenemase (KPC)-producing E. coli (R: KPC) and New Delhi metallo-β-lactamase (NDM)-producing E. coli (R: NDM). A susceptible E. coli (S) strain was used as a control, a reference bacterium. The gMNPs successfully extracted and concentrated E. coli (R) and E. coli (S) at low concentrations from large volumes of buffer solution, water, and food samples. The gMNPs concentrated up to two and five times their initial concentration for E. coli (R) and E. coli (S) in the buffer solution, respectively. In water and food samples, the concentration of E. coli (S) and E. coli (R) were similar and ranged 1-3 times their initial inoculation. A variation in the concentration from different food samples was seen, displaying the impact of food microstructure and natural microflora. The cost-effective and rapid bacterial cell capture by gMNPs was achieved in 15 min, and its successful binding to the bacterial cells in the buffer solution and food matrices was also confirmed using Transmission Electron Microscopy (TEM). These results show promising applications of gMNPs to extract pathogens and ARB from biological samples.

Assessing the recovery of dodecanol from alkyl polyglycosides (APG) using solvent extraction

Dodecanol, known as lauryl alcohol, is commonly used in the production of alkylpolyglycosides (APG) by reacting dextrose with an excess of dodecanol in the presence of an acid catalyst. After the reaction is completed, the challenging part is the purification step, to separate unreacted dodecanol from APG to ensure the final product meets an industrial specification requiring less than 5% of the dodecanol residue. Current separation methods i.e., evaporation and distillation, require high energy and could deteriorate the product quality if it is not operated carefully. In this research, the extraction process was evaluated to separate the unreacted dodecanol without compromising the quality of the final product. The study investigates the effect of the solvent matrix, temperature and stirring speed for the extraction of dodecanol using a mixture of water with ethanol, propanol or toluene as a solvent matrix. The composition ratio of sample: solvent: water was fixed at 10:10:10 (in mL). The extraction temperature was manipulated between 60 °C and 80 °C and stirring speed was at 5 and 7 rpm. In addition, the extraction was also subjected to the ultrasonic frequency set at 9 Hz for 30 min and using toluene as a matrix solvent. Results show that higher extraction yield was obtained at low temperatures and stirring speed. By using a solvent matrix-toluene leads to the highest extraction yield of 15.02 w/w%. Applying ultrasonic during the extraction process increased the extraction yield to 32 w/w%, indicating that the ultrasonic has intensified the extraction process. In conclusion, the excess of dodecanol in the APG sample could be separated via an extraction process. This potential method allows an alternative separation technique at a low investment cost, energy saving and eventually meeting the APG’s product specifications requirement.[copyright information to be updated in production process]

In Situ Capturing and Counting Device for the Specific Depletion and Purification of Cancer-Derived Exosomes.

From metabolic waste to biological mediators, exosomes have emerged as the key player in a variety of pathological processes, particularly in oncogenesis. The exosome-mediated communication network involves nearly every step of cancer progression, promoting the proliferation and immune escape of cancer cells. Therefore, the removal of cancer-derived exosomes has profound clinical significance. Current methods for exosome separation and enrichment are either for large-scale samples or require complex pretreatment processes, lacking effective methods for trace-volume exosome capture in situ. Herein, we have developed an in situ exosome capturing and counting device based on the antibody-functionalized capillary. Specific antibodies targeting exosome biomarkers were immobilized to the inner wall of the capillary via biotin-streptavidin interaction for direct cancer exosome capturing. Subsequent exosome staining enabled imaging and enumeration. Acceptable linearity and reproducibility were achieved with our device, with the capturing and detective range between 3.3 × 104 and 3.3 × 108 particles, surpassing the nanoparticle tracking analysis by 2 orders of magnitude while requiring merely 30 μL sample. We demonstrated that MCF-7-derived exosomes induced epithelial-mesenchymal transition of epithelial cells MCF-10A, and our method was able to completely or partially reverse the transition by complete depletion or specific depletion of cancer exosomes without any preprocessing. Moreover, both whole exosomes and cancer-specific exosomes alone from mimic blood samples were successfully captured and counted, without obvious non-specific adsorption. In all, our approach realized the in situ depletion and number-counting of cancer-derived exosomes directly from the complex humoral environment, having the potential to provide a comprehensive tumor therapeutic and prognosis evaluation tool by targeted hemodialysis and counting of tumor-derived exosomes.

ONLINE BINAURAL SPEECH SEPARATION OF MOVING SPEAKERS WITH A WAVESPLIT NETWORK.

Binaural speech separation in real-world scenarios often involves moving speakers. Most current speech separation methods use utterance-level permutation invariant training (u-PIT) for training. In inference time, however, the order of outputs can be inconsistent over time particularly in long-form speech separation. This situation which is referred to as the speaker swap problem is even more problematic when speakers constantly move in space and therefore poses a challenge for consistent placement of speakers in output channels. Here, we describe a real-time binaural speech separation model based on a Wavesplit network to mitigate the speaker swap problem for moving speaker separation. Our model computes a speaker embedding for each speaker at each time frame from the mixed audio, aggregates embeddings using online clustering, and uses cluster centroids as speaker profiles to track each speaker throughout the long duration. Experimental results on reverberant, long-form moving multitalker speech separation show that the proposed method is less prone to speaker swap and achieves comparable performance with u-PIT based models with ground truth tracking in both separation accuracy and preserving the interaural cues.

Extracellular Vesicles Isolation from Large Volume Samples Using a Polydimethylsiloxane-Free Microfluidic Device.

Extracellular vesicles (EV) have many attributes important for biomedicine; however, current EV isolation methods require long multi-step protocols that generally involve bulky equipment that cannot be easily translated to clinics. Our aim was to design a new cyclic olefin copolymer-off-stoichiometry thiol-ene (COC-OSTE) asymmetric flow field fractionation microfluidic device that could isolate EV from high-volume samples in a simple and efficient manner. We tested the device with large volumes of urine and conditioned cell media samples, and compared it with the two most commonly used EV isolation methods. Our device was able to separate particles by size and buoyancy, and the attained size distribution was significantly smaller than other methods. This would allow for targeting EV size fractions of interest in the future. However, the results were sample dependent, with some samples showing significant improvement over the current EV separation methods. We present a novel design for a COC-OSTE microfluidic device, based on bifurcating asymmetric flow field-flow fractionation (A4F) technology, which is able to isolate EV from large volume samples in a simple, continuous-flow manner. Its potential to be mass-manufactured increases the chances of implementing EV isolation in a clinical or industry-friendly setting, which requires high repeatability and throughput.

Numerical investigation of centrifugal passive cell separation in three types of serpentine microchannels and comparison with fixed platform

Cell separation plays a crucial role in diagnosing and improving a wide range of diseases, such as cancer, which is a severe reason for the death of people in the current decades. Circulating tumor cells (CTCs) inside the blood can be separated from the other whole blood cells to detect early cancer. Inertial methods are more superficial and cost less than the current CTC separation methods. These methods also have great potential in high-throughput separation in lab-on-a-chip (LOC) and lab-on-a-disk (LOD) devices because of secondary flow generation, especially in serpentine-shaped microchannels. The present study considers a continuous process for separating CTCs from the blood sample. This process is utilized in LOD devices, and this platform is also compared with the LOC platform. Moreover, two common types of different serpentine-shaped channels (simple and curved) and a new Omega channel are compared. It should be noted that a direct numerical simulation (DNS) method is used for calculating lift force in the serpentine-shaped channels. The effect of fluid velocity on WBC and CTC separation efficiency in the three mentioned different geometries are investigated in both fixed and rotational platforms, then the best results for each of them are presented. Finally, the best results belonged to the simple serpentine between the three investigated channels, with a separation percentage of 100. Moreover, in comparing the two mentioned platforms, LOD showed a more efficient application in cell separation. In addition, the Omega channel is investigated as a novel serpentine geometry. According to the results, it can be used for particle focusing applications thanks to its 100 percent efficiency at 0.5 m/s in both LOD and LOC platforms.

Refined decomposition: A new separation method for RAP materials and its effect on aggregate properties

In order to high-content and high-quality use of reclaimed asphalt pavement (RAP), the separation of aged asphalt and aggregates in RAP is necessary. However, the current separation methods are either inefficient, unsafe or costly. The objectives of this study are to propose a new separation method named refined decomposition (RD) and evaluate its separation efficiency and effect on aggregate properties. Quantitative indexes of asphalt removal percentage and weight loss percentage were proposed through asphalt extraction test to evaluate the separation degree of asphalt and agglomeration degree of RAP. The morphological and mechanical properties of RAP aggregates recycled from RD process were evaluated by aggregate imaging measurement system and crushing value test. The results showed that the separation degree is about 30–45 % and the agglomeration degree is reduced by 20 % for coarse RAP using RD method. The improved stability of the processed RAP is observed as well. The strength of aggregates is slightly enhanced, the angularity is slightly reduced, and the sphericity and texture are scarcely affected after RD process. In view of the acceptable changes in properties of aggregates, the RAP materials from the efficient RD process can be used in the pavement.

Zeolites in Adsorption Processes: State of the Art and Future Prospects.

Zeolites have been widely used as catalysts, ion exchangers, and adsorbents since their industrial breakthrough in the 1950s and continue to be state-of the-art adsorbents in many separation processes. Furthermore, their properties make them materials of choice for developing and emerging separation applications. The aim of this review is to put into context the relevance of zeolites and their use and prospects in adsorption technology. It has been divided into three different sections, i.e., zeolites, adsorption on nanoporous materials, and chemical separations by zeolites. In the first section, zeolites are explained in terms of their structure, composition, preparation, and properties, and a brief review of their applications is given. In the second section, the fundamentals of adsorption science are presented, with special attention to its industrial application and our case of interest, which is adsorption on zeolites. Finally, the state-of-the-art relevant separations related to chemical and energy production, in which zeolites have a practical or potential applicability, are presented. The replacement of some of the current separation methods by optimized adsorption processes using zeolites could mean an improvement in terms of sustainability and energy savings. Different separation mechanisms and the underlying adsorption properties that make zeolites interesting for these applications are discussed.