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Separation and Purification Technology
Elsevier Science B.V.
Separation and Purification Technology

Elsevier Science B.V.

1383-5866

Separation and Purification Technology/Journal Separation and Purification TechnologySCIEIISTP
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    XAS/DRIFTS/MS spectroscopy for time-resolved operando study of integrated carbon capture and utilisation process

    Hongman SunChunfen WangShuzhuang Sun
    9页
    查看更多>>摘要：An integrated carbon capture and utilization (ICCU) process present an ideal solution to address anthropogenic carbon dioxide (CO2) emissions from fossil fuel-driven electricity production, allowing for capturing and subsequent utilization of CO2 instead of current release into the atmosphere. Effective dual-functional materials (DFMs), through the combination of CO2 sorbents and catalysts, can not only capture CO2 but also convert it into higher-value chemicals, such as CH4 or CO, under isothermal conditions within a single reactor are highly desirable for ICCU processes. In this study, we investigate the mechanism of ICCU over 10 %NiCaO by the time-resolved operando XAS/DRIFTS/MS and the influence of a reduction pretreatment on the process and the products formed. During the 1st stage of the ICCU process (carbon capture), CaO adsorbs CO2 resulting in bicarbonate, carbonate, and formate species formation. At the same time, the Ni catalytic active species are oxidized by CO2, leading to the formation of NiO and CO. However, pre-treating the same DFM under hydrogen, during heating to operating temperature, resulted in a switch to CH4 production, suggesting the presence of high levels of surface adsorbed H2. During the 2nd stage of ICCU (CO2 conversion), the NiO generated during capture is reduced by H2 to metallic Ni, which facilitates the reduction of bicarbonate s, carbonates, and formats, via H2 dissociation, to produce and liberate gaseous CO. Thus, both adsorption and catalytic sites are regenerated for the subsequent ICCU cycle.
      原文链接:
    • NSTL

    Scalable purification of single stranded DNA scaffolds for biomanufacturing DNA-origami nanostructures: Exploring anion-exchange and multimodal chromatography

    A. Rita Silva-SantosPedro M.R. PauloDuarte Miguel F. Prazeres
    8页
    查看更多>>摘要：DNA-origami biomanufacturing relies in many cases on the use of asymmetric PCR (aPCR) to generate 500-3500 base, object-specific, single-stranded DNA (ssDNA) scaffolds. Each scaffold is usually purified by agarose gel extraction, a technique that is laborious, limited, not scalable, presents low recovery yields and a low-quality product. Alternatively, we present a chromatography-based method to purify ssDNA scaffolds from aPCR mixtures, which can be used in the context of DNA-origami techniques. aPCR was performed to generate single and double-stranded DNA (dsDNA) from the M13mp18 genome. To isolate the target ssDNA from dsDNA and other PCR impurities, anion-exchange (Q-ligand) and multimodal chromatography (Capto~(TM) adhere ImpRes) were explored using stepwise gradients with increasing NaCl concentrations. In anion exchange chromatography, the less-charged ssDNA eluted before the dsDNA. In multimodal chromatography, however, the elution pattern was reversed, highlighting the importance played by hydrophobicity. In either case, collected ssDNA-containing fractions were homogeneous and impurity free. Finally, 8.4 μg of a 1000-nt ssDNA fragment was purified and used alongside with site-specific short oligonucleotides (staples) to assemble 63-bp edge length, tetrahedrons. Gel electrophoresis showed high assembly yield and purity, whereas fluorescence correlation spectroscopy confirmed that the tetrahedrons had a diffusion coefficient (26.7 μm~2 s~(-1)) consistent with the expected size (20 nm).
      原文链接:
    • NSTL

    Phosphotungestic acid and manganese containing periodic mesoporous organosilica with imidazolium ionic liquid framework: A robust and durable nanocomposite for desulfurization of aromatic sulfur in diesel fraction

    Hassan M.A. HassanMohamed A. BetihaMosaed S. Alhumaimess
    13页
    查看更多>>摘要：As sulfur compounds produced by the combustion of fossil fuels are one of the main elements in air pollution, some strict legislation has been issued that specifies the sulfur ratios of different fuels. Therefore, periodic mesoporous organosilicas (PMO) composed of 1,3- bis(trimethoxysilylpropyl)imidazolium chloride ionic liquid, 1,2- bis(trimethoxysilyl)ethane, and phosphotungstic acid or permanganate as counter ions of imidazolium moieties in the framework of PMO-IL were fabricated to obtain highly reactive -MnO4 or -HPW_(12)O_(40) based heterogeneous catalysts. The synthesized materials were characterized by FT-IR, N2 adsorption-desorption, low and wide-XRD, XPS, TGA, and HRTEM. The surface area was of 615,425 and 347 m~2 g~(-1) for PMO-IL, HPW_(12)O_(40)-PMO-IL and MnO4- PMO-IL, respectively. The desulfurization was studied on three types of aromatic sulfur models. The results revealed that MnO4-PMO-IL and HPW_(12)O_(40)- PMO-IL outperform other catalysts in the oxidative desulfurization process of three kinds of aromatic sulfur compounds; comprising benzothiophene, dibenzothiophene, and 4, 6-dimethyldibenzothiophene even at smaller O/S ratio. The MnO4-PMO-IL catalyst showed the maximum efficiency in reducing sulfur at 50 °C, as it achieved sulfur reduction rates of 93.2, 92.7, and 98.8% after 90 min, while the HPW_(12)O_(40)- PMO-IL catalyst showed a reduction of sulfur by 85.1, 94.3 and 98% after 120 min for BT, DBT, and 4,6-DMDBT compounds, respectively. The two catalysts can be suggested as effective catalysts for oxidative desulfurization of fuel. Furthermore, our research showed that the catalyst might be retrieved and reused at least nine times without a noticeable loss in performance.
      原文链接:
    • NSTL

    Study on amino-directed modification of oil sludge-derived carbon and its adsorption behavior of bisphenol A in water

    Yucheng LiuSheng ZhouRui Liu
    13页
    查看更多>>摘要：In order to remove bisphenol A (BPA) in wastewater, this paper reported an amino-functionalized oily sludge-derived carbon (GP-H-OSC) obtained by grafting amino groups using oily sludge as a precursor, which could quickly adsorb BPA in the wastewater. The adsorption results showed that the grafting modification method was more likely to form effective adsorption sites on the surface than the impregnation modification. FT-IR and Boehm titration results indicated that the oxidation modification strategy was beneficial in generating more carboxyl groups on the surface of the oily sludge-derived carbon, which could provide intermediate connection groups for the subsequent grafting. The SEM and BET results revealed that the polyethyleneimine (PEI) would form a dense mesoporous structure on the surface during the grafting process, which was conducive to the transport of pollutants. The adsorption process of BPA by GP-H-OSC conformed to the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum extent of BPA adsorption was 393.2 mg/g based on the Langmuir isotherm model. Based on the analysis of FT-IR and XPS, GP-H-OSC mainly trapped BPA in water through the formation of hydrogen bonds between the functional amino groups on the surface and the hydroxyl groups on BPA. Moreover, primary amines were more likely to form hydrogen bonds with hydroxyl groups on BPA than imines. The removal rate of GP-H-OSC for low concentration BPA wastewater could reach 95% within 1 h, and it still had strong adsorption performance after recycling experiments. In summary, it was feasible to graft PEI on the surface of sludge-derived carbon, and the obtained amino-functionalized carbon material could adsorb BPA quickly and efficiently, showing great potential in practical wastewater treatment.
      原文链接:
    • NSTL

    Three-dimensional lattice Boltzmann simulation of reactive transport and ion adsorption processes in battery electrodes of cation intercalation desalination cells

    Rui LiuJianguo LuoShouguang Yao
    17页
    查看更多>>摘要：Cation intercalation desalination (CID) has gained great popularity in the field of water desalination because of its excellent desalination performance. Due to lack of understanding of the relationship between electrode microstructures and reactive adsorption processes in CIDs, the further development of high-performance CID electrodes has been hindered. To this end, the influences of electrode microstructures on the desalination performance of CID cells were investigated from the pore-scale level in this work. The three-dimensional microstructures of porous electrodes are first reconstructed by an improved random generation method. Based on the reconstructed porous electrodes, the flow, mass transfer and intercalation reaction processes under the constant current are simulated using the lattice Boltzmann method. The effects of applied current density, porosity and size of active particles on the change of liquid-phase sodium concentration and Na-intercalated degree in the solid phase are evaluated. The simulation results show that increasing the current density can accelerate the ion intercalation and desalination rates. During the desalination, the ion concentration is unevenly distributed in the pores of porous electrodes, and the intercalation degrees are different along the electrode thickness direction and in the particle radial direction. The increase of porosity can alleviate the concentration polarization of liquid-phase sodium ion and reduce the difference of particle intercalation degree between the front- and back-sides of the electrode. In addition, the increase of porosity can accelerate the desalination process, but cannot improve the total salt removal. Reducing particle size can shorten the time for particles to reach the sodium-rich state, but it can aggravate the polarization of sodium ion concentration in the liquid phase at both ends of the electrode. This work reveals the ion intercalation behavior in the CID and its relationship with the electrode microstructures, and may provide useful information for the design and research of CID.
      原文链接:
    • NSTL

    A review on the preparation of thin-film YSZ electrolyte of SOFCs by magnetron sputtering technology

    Ying YangYanxiang ZhangMufu Yan
    23页
    查看更多>>摘要：Solid oxide fuel cells (SOFCs) have become one of the most attractive energy conversion devices due to their fuel flexibility, environmental friendliness and promising energy conversion efficiency. However, the high operating temperature (typically above 800 °C) of SOFCs poses some challenges concerning stability, sealing integrity and safety. Reducing the operating temperature of SOFCs to 600 °C or lower is currently an important research topic in the field. One effective strategy is to reduce the thickness of the electrolyte with high stability and high performance at lower temperatures. Among the thin-film preparation technologies, magnetron sputtering is gaining attention due to the advantages in scaling up and commercialization. Here we compare and analyze various electrolyte preparation methods and present a comprehensive review of the preparation of oxygen-ion-conducting electrolyte thin films by magnetron sputtering technology. The yttria-stabilized zirconia (YSZ) electrolyte and YSZ-based bilayer or multilayer electrolyte are employed as examples due to their high stability and high ionic conductivity. The effects of processing parameters on the microstructures and properties of the electrolyte thin films, the relevant interfaces and full SOFCs are reviewed and discussed. Finally, we present some perspectives and directions for developing high-performance SOFCs with thin-film electrolytes prepared by magnetron sputtering technology.
      原文链接:
    • NSTL

    Rapid and effective nitrate reduction over wide pH range using CuxO-CNT with the presence of KBH4: The role of in situ produced hydrogen and zero-valent copper

    Zhiyu WeiLu FanAji Egu
    9页
    查看更多>>摘要：CNTs-CuxO prepared by impregnation was used with KBH4 to reduce NO3~-N as the first step. CNTs-CuxO was characterized by SEM, EDS-mapping, TEM, XRD and XPS. The NO3--N reduction batch experiment showed that 100% of NO3~--N removal efficiency was achieved in < 10 min with the initial pH of 3.0, 5.0 and 7.0, NO3--N concentration of 30 mg(N)/L, CNTs- CuxO dosage of 3 g/L and KBH4 concentration of 3 mmol/L. At the initial pH of 9.0, NO3~--N was completely removed in 15 min. The main product of the first step reaction was NO2~--N, which was accumulated in the solution and rapidly reduced to N2 by NH2SO3H as the second step. The reusability of CNTs-CuxO was evaluated and the experiment result showed that 96% of NO3~--N removal efficiency was achieved in 10 min after CNTs-CuxO was reused for 5 cycles of reaction. Moreover, the Cu~(2+) dissolution was kept monitored for the reaction system, and the analysis result showed that there was no Cu~(2+) leaching for all cycles of reutilization.
      原文链接:
    • NSTL

    Ultra-high flux and synergistically enhanced anti-fouling Ag@MXene lamellar membrane for the fast purification of oily wastewater through nano-intercalation, photo catalytic self-cleaning and antibacterial effect

    Qingying FengYingqing ZhanWei Yang
    15页
    查看更多>>摘要：The membrane fouling from oils, soluble organic matters, and microorganism is inevitable in practical application of oil/water separation, which easily causes the decline in flux and service life of membrane. Therefore, developing the advanced separation membrane with high flux and anti-fouling feature is still a big challenge. Herein, we report a facile strategy to prepare the multifunctional Ag@MXene/PEN fibrous composite membrane by the self-assembly of Ag@MXene hybrid on electrospun poly (arylene ether nitrile) (PEN) porous support. In the hierarchical skin layer of fibrous composite membrane, the silver nanoparticles (AgNPs) were anchored onto the MXene surface via the self-reduction of silver nitrate, in which the MXene acted as reductant. Meanwhile, the Ag@MXene hybrid was stabilized and modified by the bio-inspired dopamine triggered crosslinking with polyethyleneimine. Because of regulated interlayer spacing, super-hydrophilic property, and porous supporting layer, the Ag@MXene/PEN fibrous composite membrane exhibited the ultra-high permeance (up to 11957.5 L·m~(-2)·h~(-1)·bar~(-1)) for different oil-water emulsions while maintaining high-level rejection rate (99.13%), which was far beyond other MXene-based composite membranes reported before. Moreover, the fibrous composite membrane showed the satisfactory photocatalytic degradation rates for the methyl orange (15 ppm, 95.24%) and crystal violet (15 ppm, 95.61%) in 60 min, demonstrating the photocatalytic self-cleaning ability for organic pollutants. In addition, the fibrous composite membrane exhibited ～ 99.99% E. coli growth inhibition, achieving the favorable antibacterial effect. Therefore, the low oil adhesion, photocatalytic self-cleaning, and antibacterial effect contributed to the synergistically enhanced anti-fouling, which enabled the membrane material to maintain high separation efficiency and long-term usage in complex multi-pollutant environments. The combination of high permeability and enhanced anti-fouling performance makes the fibrous composite membrane an ideal candidate for the fast purification of emulsified oily wastewater.
      原文链接:
    • NSTL

    Deep eutectic solvents based biorefining of Value-added chemicals from the diatom Thalassiosira andamanica at room temperature

    Kuldeep SinghMurali Krishna PaidiAkshay Kulshrestha
    15页
    查看更多>>摘要：The extraction and biorefining of value-added chemicals from bioresources using green solvents are among the key agenda of the circular bioeconomy. Herein we have developed a deep eutectic solvent (DESs) based biorefining approach for clean separation and purification of value-added Fucoxanthin, Chlorophyll, and Biosilica from a diatom microalgae, Thalassiosira andamanica. Several hydrophilic/hydrophobic (DESs) based on quaternary ammonium salt as hydrogen bond acceptor and organic acids and alcohols as hydrogen bond donors were synthesized and tested for microalgae biomass dissolution and biorefining via the phase partitioning method. In an optimized process, ～30 wt% of fresh weight diatom could be dissolved in hydrophilic DESs at room temperature, followed by a record extraction of 19.93 mg/g of Fucoxanthin via phase partitioning, with a 53 % increase in yield and an 81 % increase in selectivity over conventional solvents. ~1H NMR, FTIR, LCMS, UV, and HPLC techniques were used to characterize the extracted Fucoxanthin. Subsequently, a hydrophobic DES was added to the remaining hydrophilic DESs and residual biomass and Chlorophyll were extracted into the upper hydrophobic DES layer and Biosilica (80 mg/g) was recovered by simple centrifugation. Extracted Biosilica showed an excellent adsorption capacity of 224.71 mg/g for the removal of methylene blue (MB) dye from water (94.3% up to 88.8 % after 4th consecutive steps). Whereas Chlorophyll extracted in the hydrophobic DES phase exhibited excellent photostability (6 folds greater than conventional solvent) indicating the efficacy of DESs as photoprotector for light-sensitive pigments. This is the first report wherein besides an extractant DES also acted as a good photostabilizer. Additionally, we have replaced the acid-based extraction method for Biosilica with non-toxic DESs.
      原文链接:
    • NSTL

    Key-study on plasma-induced degradation of cephalosporins in water: Process optimization, assessment of degradation mechanisms and residual toxicity

    S. MeropoulisS. GiannouliaS. Skandalis
    15页
    查看更多>>摘要：Cephalosporins is a class of β-lactam antibiotics being widely used and often released uncontrollably in aquatic systems thus resulting in serious environmental contamination. In this work, we investigated for the first-time the degradation of cephalexin (CPX) and cefazolin (CFZ) by nanosecond-pulsed cold atmospheric plasma (NSP-CAP) using a multi-pin-to-liquid corona reactor, proposing special degradation pathways of both cephalosporins and assessing their residual toxicities. Increasing pulse voltage and frequency enhanced RONS concentration and energy input into the system both of which led to improved plasma-induced cephalosporin degradation efficiency, rate and energy yield, the latter being two orders of magnitude higher (0.84-1.37 g/kWh) than those reported for their photocatalytic degradation. O2- and air-plasmas displayed superior performance compared to N2-plasma due to the increased ROS concentration. The prevailing role of the short-lived · OH and ~1O2 in the degradation process compared to the long-lived H2O2 and plasma electrons was confirmed. Nevertheless, the identical degradation efficiencies between air and oxygen indicated the possible significant contribution of some RNS (e.g. ONOOH/ONOO~-) generated due to nitrogen content in air-plasma. The plasma-induced degradants of CPX and CFZ were interrogated by UPLC/MS, comprehensive degradation maps were proposed and reduced cytotoxicity was demonstrated for both CPX and CFZ plasma-treated solutions. Given than CPX and CFZ are resistant to human (and other species) metabolism/degradation, this work supports that CAP constitutes arguably one of the most efficient remediation technologies to date.
      原文链接:
    • NSTL