Conventional Separation Methods Research Articles

Tensor Low-Rank and Sparse Decomposition and Its Application in Bearing Fault Information Separation

Abstract Properly separating fault information from noisy measured signals is crucial for effective bearing health sensing. However, conventional fault information separation methods face challenges such as predefined model parameters and poor noise robustness. Additionally, with the advent of Industry Big Data, multichannel monitoring signals present significant challenges for traditional single decomposition approaches. To address these challenges and fully extract potential fault information, this paper introduces a tensor low-rank and sparse decomposition (tensor LRSD) approach for multichannel signal processing. Inspired by matrix LRSD, we construct a tensor LRSD model that adaptively decomposes the signal into a tensor sparse term containing fault information and a low-rank term representing the intrinsic signal pattern. To further enhance the decomposition performance, a maximum correlation-based selection strategy is designed. This strategy evaluates the correlation between each tensor slice and selects appropriate tensor sparse terms for fault information extraction. Simulation analysis and two experimental studies involving typical bearing failures are implemented to verify the capability and superiority of the presented tensor LRSD approach. The consequences demonstrate that the presented method outperforms conventional techniques, showcasing its capability to effectively separate fault information from noisy signals.

Water-modification of micro- and nano-adsorbents: A strategy for enhancing biodiesel refining efficiency

In this study, we compared nanometer-scale (nm) silica (SiO2) and alumina (Al2O3) with conventional micrometer-scale (μm) adsorbents (SiO2 and Al2O3) to determine their utility in refining crude fatty acid methyl esters (FAME). Unlike their μm counterparts, hydrated SiO2 and Al2O3 nm-adsorbents did not retain water after utilization in FAME refining. However, hydrated adsorbents significantly improved performance of μm-scale SiO2 and Al2O3 adsorbents for FAME refining. Structurally, the μm-adsorbents are porous multi-layered structures, with FAME adhering to the surface or entrained between layers. Meanwhile, nm-adsorbents were aggregated. As such, FAME loss associated with nm-SiO2 adsorbent was 50.5 % higher than μm-SiO2 adsorbent. In addition, the electrical charge density of the adsorbents influenced their performance in FAME refining. Finally, conventional separation methods (e.g., gravitational setting) were impractical for separating spent nm-adsorbents from FAME; although, the use of an electrostatic field enhanced the removal of nm-adsorbents from solution. Altogether, this study examines the application of nm-adsorbents, compared to μm-adsorbents, and highlights potential increased efficiency in refining biodiesel, such as potentially reducing the need for extensive wet washing processes. Although new separation technologies may be required in recovering spent nm-adsorbents, their application could enhance the sustainability and cost efficiency of biodiesel production.

Analysis of wettability and oil-water separation mechanism of superhydrophilic/underwater superoleophobic mesh based on capillary force model

The Frequent oil spills at sea and large discharges of oily wastewater spills seriously jeopardize the ecological environment and lead to an increasing shortage of water resources, so the oil/water separation has become a hot spot of global research. As opposed to the conventional separation method, the membrane separation has received wide attention because of its advantages of green environmental protection, low energy consumption and easy operation. In this paper, Cu(OH)2 mesh with superhydrophilic and underwater superoleophobic properties were prepared by in-situ growth method using purple copper mesh as the substrate. Scanning electron microscopy, x-ray photoelectron spectroscopy and contact angle tests were used to evaluate the surface morphology, chemical composition and wetting behavior of the mesh. The results showed that the water contact angle was 0° in air and the contact angle was 155.4° for oil droplets underwater. The membrane exhibited high separation efficiencies (99%) and separation fluxes (3.67-6.54×104 L·m-2·h-1) for the five tested oils under gravity drive. The wettability of the mesh was unaffected after 20 separation experiments. The surface wettability and the oil/water separation mechanism were analyzed using the capillary force-based separation model combined with the Young and Cassie-Baxter equations.

The electrochemistry of stable sulfur isotopes versus lithium

Sulfur in nature consists of two abundant stable isotopes, with two more neutrons in the heavy one (34S) than in the light one (32S). The two isotopes show similar physicochemical properties and are usually considered an integral system for chemical research in various fields. In this work, a model study based on a Li-S battery was performed to reveal the variation between the electrochemical properties of the two S isotopes. Provided with the same octatomic ring structure, the cyclo-34S8 molecules form stronger S-S bonds than cyclo-32S8 and are more prone to react with Li. The soluble Li polysulfides generated by the Li-34S conversion reaction show a stronger cation-solvent interaction yet a weaker cation-anion interaction than the 32S-based counterparts, which facilitates quick solvation of polysulfides yet hinders their migration from the cathode to the anode. Consequently, the Li-34S cell shows improved cathode reaction kinetics at the solid-liquid interface and inhibited shuttle of polysulfides through the electrolyte so that it demonstrates better cycling performance than the Li-32S cell. Based on the varied shuttle kinetics of the isotopic-S-based polysulfides, an electrochemical separation method for 34S/32S isotope is proposed, which enables a notably higher separation factor than the conventional separation methods via chemical exchange or distillation and brings opportunities to low-cost manufacture, utilization, and research of heavy chalcogen isotopes.

Effective separation of maslinic acid and oleanolic acid from olive pomace using high-speed shear off-line coupled with high-speed countercurrent chromatography and their antibacterial activity test

In this work, a high-speed shear extraction off-line coupling high-speed countercurrent chromatography method was developed to separate maslinic acid and oleanolic acid from olive pomace. To improve extraction efficiency, the polar disparity between maslinic acid and oleanolic acid necessitated the concurrent utilization of both polar and non-polar solvents during high-speed shear extraction. Then, the high-speed shear extraction was directly feed to high-speed countercurrent chromatography for subsequently separation. A total of 250 min were needed to complete the extraction and separation process. This yielded two molecules from 3.3 g of defatted olive pomace: 7.2 mg of 93.8 % pure maslinic acid and 2.3 mg of 90.1 % pure oleanolic acid, both determined by HPLC at 210 nm. Furthermore, the compounds exhibited inhibitory activity against Escherichia coli and Staphylococcus aureus. At a concentration of 100 μg/mL, its efficacy in inhibiting hyaluronidase was comparable to that of the standard drug indomethacin. Compared with the conventional separation method, this coupled technique reduced the whole time due to the direct injection of sample extraction solution. This technique provides a useful approach for the separation of natural products with significant polarity differences.

Efficient removal of Mo(VI) ions via adsorbing colloid flotation based on the synergic effect of metal salts and CTAB

Treatment of molybdenum-containing wastewater is crucial for mitigating the environmental threat of Mo(VI) ions and recovering valuable metals. Compared to conventional separation methods, adsorbing colloid flotation emerges as a viable way to efficiently remove Mo(VI) ions. However, the current colloidal adsorption reagents have constrained the development of adsorbing colloid flotation due to their poor removal efficiency and narrow solution pH range. To overcome these challenges, Zr(IV) salts and La(III) salts were employed as colloidal adsorption reagents for the first time to remove Mo(VI) ions from wastewater in this work. In particular, the differences in removal efficiency of Mo(VI) ions between Zr(IV) salts, La(III) salts and traditional Fe(III) salts were systematically evaluated over a wide solution pH range. Zr(IV) salts demonstrated robust pH stability, displaying a significant removal efficiency of over 70.00% for Mo(VI) ions during the colloidal adsorption stage across a broad solution pH range from 3 to 11. Even more astonishingly, the removal efficiency of Mo(VI) ions was further enhanced through the synergistic effect of cetyltrimethylammonium bromide (CTAB) during the flotation separation stage. Under the optimal conditions of bubble flotation, the solution turbidity decreased rapidly from 164.50 NTU to 3.33 NTU, and the removal efficiency of Mo(VI) ions reached an impressive 99.10% which was enhanced by 23.73% compared to the colloidal adsorption stage. In conclusion, Zr(IV) salts, serving as colloidal adsorption reagents, have overcome the limitations of traditional colloidal adsorption reagents and exhibit significant potential for the removal of Mo(VI) ions from wastewater.

Integrated Microfluidics for Single‐Cell Separation and On‐Chip Analysis: Novel Applications and Recent Advances

From deciphering infection and disease mechanisms to identifying novel biomarkers and personalizing treatments, the characteristics of individual cells can provide significant insights into a variety of biological processes and facilitate decision‐making in biomedical environments. Conventional single‐cell analysis methods are limited in terms of cost, contamination risks, sample volumes, analysis times, throughput, sensitivity, and selectivity. Although microfluidic approaches have been suggested as a low‐cost, information‐rich, and high‐throughput alternative to conventional single‐cell isolation and analysis methods, limitations such as necessary off‐chip sample pre‐ and post‐processing as well as systems designed for individual workflows have restricted their applications. In this review, a comprehensive overview of recent advances in integrated microfluidics for single‐cell isolation and on‐chip analysis in three prominent application domains are provided: investigation of somatic cells (particularly cancer and immune cells), stem cells, and microorganisms. Also, the use of conventional cell separation methods (e.g., dielectrophoresis) in unconventional or novel ways, which can advance the integration of multiple workflows in microfluidic systems, is discussed. Finally, a critical discussion related to current limitations of integrated microfluidic single‐cell workflows and how they could be overcome is provided.

A Novel Circuit-Based Model of Electrodialysis Avoiding the Use of Empirical Parameters

Electrodialysis (ED) is an emerging membrane-based electroseparation technology for desalination, water treatment, and ionic pollutant removal. Compared to conventional separation methods such as reverse osmosis, ED offers several advantages including lower energy consumption, higher selectivity, and lower fouling propensity. Further, coupling ED with renewable electricity sources enables it to be far more sustainable than competing technologies (reverse osmosis and evaporation) across a wide range of scales. However, the design and operation of ED systems are still challenging due to the complex interactions between the membrane, the electrolytes, and the applied electric field. To address this issue, advanced process models are required to provide accurate predictions of ED performance and to guide system optimisation. Existing ED models tend to be highly dependent on empirical parameters and thus are only applicable to a narrow range of process conditions and require several data sets to validate. Therefore, in this work we aimed to develop a glabal model of ED without reliance on experimental training data.Herein, we present a novel circuit-based model for ED. The model considers the membrane stack as a series of resistors, where the membranes and electrolytes are represented as separate resistive elements. Crucially, the membrane resistance is calculated directly from the electrostatic interaction between ions and fixed charge groups, rather than from manufacturer data or empirical sub-model. This allows for consideration of the ion identity and electrolyte concentration when determining the membrane resistance. Ohm's law is used to relate the applied voltage and stack electrical resistance to a current density, which is then converted to a flux using Faraday's law and current efficiency model. Historically, current efficiencies are calculated from transport numbers provided from membrane manufactures and assumed constant. A novel model for the current efficiency has been developed by us in which the current efficiency is a function of the trans-membrane concentration difference. A space-wise material balance is employed to determine the concentration profile along the stack, while a time-wise material balance tracks the changes in reservoir concentration for recirculating batch experiments.To validate the model, desalination experiments were conducted on a PC BED 1-4 recirculating batch system and compared the model predictions with experimental data. The model demonstrated excellent matching on a range of variables across a range of conditions, including current density, current efficiency, and ion concentration.The proposed model has various applications in ED process modelling, optimisation, and economic analysis. It can be used to evaluate the impact of different design parameters such as membrane thickness, membrane charge density, and flow rate on system performance as well as to optimise these.In summary, the circuit-based model presented in this work offers a robust and versatile tool for ED process simulation and optimisation, which can be used for effective and efficiency desalination and water treatment. Two major advancements presented include models for the membrane electrical resistance and current efficiency, which have historically been considered constant. Figure 1

Purification of hydrogenated oil by microchannel separation coupling hydrocyclone

Hydrogenated oils are commonly used as solvents in the petroleum resin industry. The separation of particulate matter from hydrotreating oil is critical to product quality and the service life of the catalyst in the downstream fixed bed. Conventional separation methods, represented by diatomaceous earth filtration, suffer from low separation efficiency, high material consumption, generation of large amounts of hazardous waste, and cumbersome operation. Therefore, a physical method of microchannel separation coupling hydrocyclone was proposed. A 1 m3/h pilot pretreatment device was established to comprehensively evaluate the particle removal in hydrogenated oil. The high separation efficiency and long operation cycle were achieved by a microchannel separator with 0.5–1 mm particle size quartz sand. The single cycle of the microchannel separator was 75 h. The turbidity was decreased by about 64.3%, which was better than that of the traditional separation method (49.9%). The particle removal in hydrogenated oil by microchannel separator was about 75.0%, while the removal of diatomite separator in the same period was only 44.7%. In a 40 m3/h petroleum resin plant based on a microchannel separator, the operating cost and the hazardous waste emissions are reduced by 1,815,000 CNY/year and 208 tons/year, respectively. It is hoped that this study can not only promote the energy-saving and cleaner production of hydrogenated oil but also provide useful guidance for other petrochemical industries.

Research advances of porous organic framework materials on enrichment and detection of mycotoxins

Mycotoxins are a class of toxic secondary metabolites produced by fungi. These substances are carcinogenic, teratogenic, and mutagenic, and cause serious harm to the human body; thus, they have attracted wide attention worldwide. Establishing accurate, rapid, and sensitive methods for the detection of mycotoxins is of great significance. Chromatography is a commonly used technology for mycotoxin detection. However, it is challenging to use in the direct analysis of these metabolites because of the wide variety and distribution of mycotoxins, their complex sample matrix, and their very low content in actual samples. Therefore, the development of suitable sample pretreatment methods for the efficient separation and enrichment of mycotoxins is necessary. In recent years, porous organic framework materials, which are represented by metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs), have been widely applied in the sample pretreatment of mycotoxins owing to their many advantages, which include a large specific surface area, high porosity, adjustable pore size, diverse frame structures, uniform active site distribution, and modifiable structures. In addition, MOF/COF materials feature excellent fluorescence and electrochemical properties, rendering them highly suitable for mycotoxin analysis and sensing. In this article, the recent applications of MOF/COF materials in conventional sample pretreatment methods (e. g., solid-phase extraction, dispersive solid-phase extraction, magnetic solid-phase extraction, and immunomagnetic bead separation) for mycotoxin separation and enrichment are reviewed. Research on the use of MOF/COF materials for the fluorescence and electrochemical sensing of mycotoxins is also summarized. Finally, the existing challenges and future development trends of these materials are discussed and prospected to provide a reference for future research on the applications of MOF/COF materials in mycotoxin detection and analysis.

Nanostructure enabled extracellular vesicles separation and detection

Extracellular vesicles (EVs) have recently attracted significant research attention owing to their important biological functions, including cell-to-cell communication. EVs are a type of membrane vesicles that are secreted into the extracellular space by most types of cells. Several biological biomolecules found in EVs, such as proteins, microRNA, and DNA, are closely related to the pathogenesis of human malignancies, making EVs valuable biomarkers for disease diagnosis, treatment, and prognosis. Therefore, EV separation and detection are prerequisites for providing important information for clinical research. Conventional separation methods suffer from low levels of purity, as well as the need for cumbersome and prolonged operations. Moreover, detection methods require trained operators and present challenges such as high operational expenses and low sensitivity and specificity. In the past decade, platforms for EV separation and detection based on nanostructures have emerged. This article reviews recent advances in nanostructure-based EV separation and detection techniques. First, nanostructures based on membranes, nanowires, nanoscale deterministic lateral displacement, and surface modification are presented. Second, high-throughput separation of EVs based on nanostructures combined with acoustic and electric fields is described. Third, techniques combining nanostructures with immunofluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrochemical detection, or piezoelectric sensors for high-precision EV analysis are summarized. Finally, the potential of nanostructures to detect individual EVs is explored, with the aim of providing insights into the further development of nanostructure-based EV separation and detection techniques.

A New Era of Modeling MOF‐Based Membranes: Cooperation of Theory and Data Science

AbstractMembrane‐based separation can offer significant energy savings over conventional separation methods. Given their highly customizable and porous structures, metal–organic frameworks‐ (MOFs) are considered as next‐generation membrane materials that can bring about high separation performance and energy efficiency in various separation applications. Yet, the enormously large number of possible MOF structures necessitates the development and implementation of efficient modeling approaches to expedite the design, discovery, and selection of optimal MOF‐based membranes via directing the experimental efforts, time, and resources to the potentially useful membrane materials. With the recent developments in the field of atomic simulations and artificial intelligence methods, a new era of membrane modeling has started. This review focuses on the recent advances made and key strategies used in the modeling of MOF‐based membranes and highlight the huge potential of combining atomistic modeling of MOFs with machine learning to explore very large number of MOF membranes and MOF/polymer composite membranes for gas separation. Opportunities and challenges related to the implementation of data‐driven approaches to extract useful structure–property relations of MOF‐based membranes and to produce design principles for the high‐performing MOF‐based membranes are discussed.

P/S wavefield separation using modified U-Net based on ConvNeXt architecture

P/S wavefields separation is an essential step in multi-component seismic data processing, significantly impacting the quality of subsequent processing workflows if not performed accurately. Conventional wavefield separation methods, called model-driven methods, primarily rely on the polarization directions of P- and S-wavefields, which are obtained depending on accurate model parameters such as velocity and density. However, seismic model building is a well-known challenge for real data. As a result, the conventional methods rarely produce ideal pure P- or S-wavefields. Deep learning (DL) techniques can solve many real-world problems by constructing complex nonlinear mappings between inputs and desired outputs based on large-scale datasets, such as image classification, semantic segmentation, and object detection. Inspired by the advantages of DL techniques, we construct a improved U-ConvNeXt network architecture by combining the U-Net with the ConvNeXt, and apply it to implement P/S wavefields separation. Compared with the conventional U-Net, the ConvNeXt has better feature extraction capabilities because it introduces the idea of transformer architecture design into CNN. Consequently, the proposed U-ConvNeXt-based P/S wavefields separation method produces cleaner P- and S-wavefields with less computational costs. In addition, the proposed method can achieve nearly the same accuracy as the conventional methods without relying on model parameters, and its computational efficiency is much higher than conventional methods. Finally, we verify the proposed method with several numerical examples, and numerical results validate the effectiveness and accuracy of the proposed P/S wavefields separation method.

Xe Recovery from Nuclear Power Plants Off-Gas Streams: Molecular Simulations of Gas Permeation through DD3R Zeolite Membrane.

Recent experimental work has shown zeolite membrane-based separation as a promising potential technology for Kr/Xe gas mixtures due to its much lower energy requirements in comparison to cryogenic distillation, the conventional separation method for such mixtures. Such a separation is also economically rewarding because Xe is in high demand, as a valuable product for many applications/processes. In this work, we have used Molecular Dynamics (MD) simulations to study the effects of different conditions, i.e., temperature, pressure, and gas feed composition, on Kr/Xe separation performance via DD3R zeolite membranes. We provide a comprehensive study of the permeation of the different gas species, density profiles, and diffusion coefficients. Molecular simulations show that if the feed is changed from pure Kr/Xe to an equimolar mixture, the Kr/Xe separation factor increases, which agrees with experiments. In addition, when Ar is introduced as a sweep gas, the adsorption of both Kr and Xe increases, while the permeation of pure Kr increases. A similar behavior is observed with equimolar mixtures of Kr/Xe with Ar as the sweep gas. High-separation Kr/Xe selectivity is observed at 50 atm and 425 K but with low total permeation rates. Changing pressure and temperature are found to have profound effects on optimizing the separation selectivity and the permeation throughput.

Green solvent mediated extraction of micro- and nano-plastic particles from water

The production of plastic and the amount of waste plastic that enters the ecosystem increases every year. Synthetic plastics gradually break down into particles on the micro- and nano-scale in the environment. The micro- and nano-plastics pose a significant ecological threat by transporting toxic chemicals and causing inflammation and cellular damage when ingested; however, removal of those particles from water is challenging using conventional separation methods. Deep eutectic solvents (DES), a new class of solvents composed of hydrogen bond donors and acceptors, have been proposed as a cheaper alternative to ionic liquids. Hydrophobic DES derived from natural compounds (NADES) show promise as extractants in liquid–liquid extractions. This study investigated the extraction efficiency of micro- and nano-plastics including polyethylene terephthalate, polystyrene, and a bioplastic polylactic acid from fresh water and saltwater using three hydrophobic NADES. The extraction efficiencies fall in a range of 50–93% (maximum % extraction) while the extraction rates fall between 0.2 and 1.3 h (as indicated by the time to extract half the theoretical maximum). Molecular simulations show a correlation between the extraction efficiency and the association between the plastics and NADES molecules. This study demonstrates the potential of hydrophobic NADES as extractants for removal of different micro- and nano-plastic particles from aqueous solutions.

Influence of the filter grain morphology on separation efficiency in dielectrophoretic filtration.

Recovery of noble materials from waste is essential for industries around the globe. Dielectrophoretic (DEP) filtration, an electrically switchable particle separation technique, can be applied to tackle this challenge. It is highly selective regarding particle size, material or shape. Expanding the scope of DEP towards high throughput and improving the trapping efficiency are vital to make DEP a viable robust alternative to conventional separation methods. DEP filtration works by selective immobilisation of particles in a porous medium by the action of an inhomogeneous electric field. The field inhomogeneity comes from scattering an electric field at the phase boundary between the particle suspension and the filter surface. In this article, we show how the filter structure affects the DEP separation. We study fixed bed filters of three different grain types and find that the morphology of the grains highly influences the DEP filter efficiency. Specifically, grains with irregular surface structure and high perceived angularity show high separation efficiency. We believe these insights into the design of DEP filtration will pave the way towards its application in, for example, the recovery of valuable materials from electronic waste dust.

Controllable growth of porous morphology in low dielectric polyimides via thermal-driven spontaneous phase separation

Fabricating porous polymer films with precise morphological control via a conventional phase separation method is challenging. Herein, porous polyimide (PPI) film formation kinetics was thoroughly investigated to understand the underlying phenomena during the thermally induced phase separation. The porous films were prepared using a poly(amic acid) (PAA) solution with a small-molecular phase dispersion agent (i.e., porogen), dibutyl phthalate (DBP), which is miscible with the PAA chains. Using amine-functionalized polyhedral oligomeric silsesquioxane (NH2-POSS) as an additional nucleating agent, sponge-like NH2-POSS end-capped PPI (PPI/NH2-POSSx) films were fabricated with tunable pore size (16.3–76.9 μm) and porosity (42.6–69.4 %). This ensured control over the porous structure of the PPI/NH2-POSSx film, providing desirable low dielectric properties (a minimum of 2 at 1 MHz) in broad frequency and temperature range as well as high thermal stability (Tg = 363–385 °C, T5% = 519–559 °C), and good mechanical strength (17–23 MPa). It was found that the porous structure and physical properties of the PPI/NH2-POSSx films can be readily engineered by tailoring the initial content of a removable porogen and cage silsesquioxane. This work will provide a new perspective on fabricating temperature-resistant low-dielectric porous polymer films with tunable pore sizes via thermal-driven spontaneous phase separation with efficient processability.

Facile and selective separation of anthraquinones by alizarin-modified iron oxide magnetic nanoparticles

Anthraquinones are widely distributed in higher plants and possess broad biological activities. The conventional separation procedures for isolating anthraquinones from the plant crude extracts require multiple extraction, concentration, and column chromatography steps. In this study, we synthesized three alizarin (AZ)-modified Fe3O4 nanoparticles (Fe3O4@AZ, Fe3O4@SiO2-AZ, and Fe3O4@SiO2-PEI-AZ) by thermal solubilization method. Fe3O4@SiO2-PEI-AZ showed strong magnetic responsiveness, high methanol/water dispersion, good recyclability, and high loading capacity for anthraquinones. To evaluate the feasibility of using Fe3O4@SiO2-PEI-AZ for separating various aromatic compounds, we employed molecular dynamics simulations to predict the adsorption/desorption effects of PEI-AZ for various aromatic compounds in different methanol concentrations. The results showed that the anthraquinones could be efficiently separated from the monocyclic and bicyclic aromatic compounds by adjusting the methanol/water ratio. The Fe3O4@SiO2-PEI-AZ nanoparticles were then used to separate the anthraquinones from the rhubarb extract. At 5% methanol, all the anthraquinones were adsorbed by the nanoparticles, thus allowing their separation from other components in the crude extract. Compared with the conventional separation methods, this adsorption method has the advantages of high adsorption specificity, simple operation, and solvent saving. This method sheds light on the future application of functionalized Fe3O4 magnetic nanoparticles to selectively separate desired components from complex plant and microbial crude extracts.

Efficient and simple simultaneous adsorption removal of multiple mycotoxins from environmental water

Developing simple and efficient simultaneous adsorption removal of multiple unwholesome mycotoxins from environmental water remains a technical challenge. To this end, we fabricate a new adsorbent, nanofiber mat modified by polydopamine and ionic liquid (PDA-IL NFsM) which can effectively absorb and simultaneous removal of multiple mycotoxins in environment water. Circumventing the pretreatment of water samples and conventional secondary separation methods, PDA-IL NFsM is applied directly and conveniently retrieved after the adsorption process. The adsorption mechanism of mycotoxins by PDA-IL NFsM involves multiple interactions, including hydrogen bond formation, π - π interaction, as well as electrostatic or hydrophobic interaction. Accordingly, compared to existing adsorbents, PDA-IL NFsM offers a greater advantage with the high removal efficiency of over 88.3 % for most of the fifteen mycotoxins belonging to seven classes. In addition, the adsorption behaviors of mycotoxins are profiled thoroughly in terms of kinetics, isotherms and thermodynamics. Our findings indicate that the adsorption of PDA-IL NFsM to mycotoxins is a spontaneous (ΔG＜0) and endothermic (ΔS＞0) process which follows the pseudo second-order model (R2＞0.9820) and Langmuir model (R2＞0.9957). With a maximum adsorption capacity of 9.35 mg g−1 for all mycotoxins, PDA-IL NFsM meets the demand of removing mycotoxins present in their actual pollution levels. Thus, our newly fabricated PDA-IL NFsM has good potential for practical application.

Evaluation of Commercial RO Membrane for BaCl2 Separation

The conventional methods of the BaCl2 solution separation are characterized by high energy consumption, reagent requirement, and other technological limitations. The pressure-driven membrane process can be an alternative, but the number of published investigations in this field is limited. The study of the effectivity of the BaCl2 diluted solution separation using the commercially available reverse osmosis membrane was carried out. It was defined that the spiral wound membrane module HID TFC 1812-75 GPD (nominal permeate flux is 281 l/d) has acceptable characteristics of productivity and selectivity. In particular, the permeate flux through these membranes for the BaCl2 solutions does not differ from the fluxes for other salt solutions in the considered range of the applied pressures (0.2-0.6 MPa). The rejection coefficient values were in the range of 0.9-0.95 and slightly varied with applied pressure. Therefore, such membranes are suitable for wastewater purification from the remains of BaCl2. At the same time, the concentration ratio does not exceed 1.5-2, consequently, the application of such membranes on the concentration stage requires deeper justification based on the economical parameters. The significant influence of the concentration polarization on the separation effectivity was not detected up to applied pressures 0.5 MPa.