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Archives of Microbiology May 2024In many European regions, both local metallic and non-metallic raw materials are poorly exploited due to their low quality and the lack of technologies to increase their...
In many European regions, both local metallic and non-metallic raw materials are poorly exploited due to their low quality and the lack of technologies to increase their economic value. In this context, the development of low cost and eco-friendly approaches, such as bioleaching of metal impurities, is crucial. The acidophilic strain Acidiphilium sp. SJH reduces Fe(III) to Fe(II) by coupling the oxidation of an organic substrate to the reduction of Fe(III) and can therefore be applied in the bioleaching of iron impurities from non-metallic raw materials. In this work, the physiology of Acidiphilium sp. SJH and the reduction of iron impurities from quartz sand and its derivatives have been studied during growth on media supplemented with various carbon sources and under different oxygenation conditions, highlighting that cell physiology and iron reduction are tightly coupled. Although the organism is known to be aerobic, maximum bioleaching performance was obtained by cultures cultivated until the exponential phase of growth under oxygen limitation. Among carbon sources, glucose has been shown to support faster biomass growth, while galactose allowed highest bioleaching. Moreover, Acidiphilium sp. SJH cells can synthesise and accumulate Poly-β-hydroxybutyrate (PHB) during the process, a polymer with relevant application in biotechnology. In summary, this work gives an insight into the physiology of Acidiphilium sp. SJH, able to use different carbon sources and to synthesise a technologically relevant polymer (PHB), while removing metals from sand without the need to introduce modifications in the process set up.
Topics: Iron; Acidiphilium; Oxidation-Reduction; Hydroxybutyrates; Polyesters; Polymers; Culture Media; Biomass; Polyhydroxybutyrates
PubMed: 38775940
DOI: 10.1007/s00203-024-04005-4 -
Advanced Materials (Deerfield Beach,... May 2024Flexible metal-organic framework (MOF) adsorbents commonly encounter limitations in removing trace impurities below gate-opening threshold pressures. Topology...
Flexible metal-organic framework (MOF) adsorbents commonly encounter limitations in removing trace impurities below gate-opening threshold pressures. Topology reconfiguration can fundamentally eliminate intrinsic structural flexibility, yet remains a formidable challenge and is rarely achieved in practical applications. Herein, a solvent-mediated approach is presented to regulate the flexible CuSnF-dpds-sql (dpds = 4,4''-dipyridyldisulfide) with sql topology into rigid CuSnF-dpds-cds with cds topology. Notably, the cds topology is unprecedented and first obtained in anion-pillared MOF materials. As a result, rigid CuSnF-dpds-cds exhibits enhanced CH adsorption capacity of 48.61 cm g at 0.01 bar compared to flexible CuSnF-dpds-sql (21.06 cm g). The topology transformation also facilitates the adsorption kinetics for CH, exhibiting a 6.5-fold enhanced diffusion time constant (D/r) of 1.71 × 10 s on CuSnF-dpds-cds than that of CuSnF-dpds-sql (2.64 × 10 s). Multiple computational simulations reveal the structural transformations and guest-host interactions in both adsorbents. Furthermore, dynamic breakthrough experiments demonstrate that high-purity CH (>99.996%) effluent with a productivity of 93.9 mmol g can be directly collected from CH/CH (1/99, v/v) gas-mixture in a single CuSnF-dpds-cds column.
PubMed: 38733317
DOI: 10.1002/adma.202401693 -
Molecules (Basel, Switzerland) Apr 2024Tripropyl phosphate (TnPP) is a commonly used organic phosphate flame retardant in the textiles, plastics, and coating industries. Residues are commonly detected in...
Tripropyl phosphate (TnPP) is a commonly used organic phosphate flame retardant in the textiles, plastics, and coating industries. Residues are commonly detected in samples from the environment and food. The availability of certified reference materials (CRMs) is essential to ensure the accuracy and traceability of detection results. In this study, a comprehensive characterization of a CRM for TnPP was carried out, and its purity was evaluated using two distinct methodologies: mass balance (MB) and quantitative nuclear magnetic resonance spectroscopy (qNMR). In the MB method, the levels of structurally related organic impurities are 1.37 mg/g. The water content was determined to be 3.16 mg/g, while inorganic impurities were found to be 0.87 mg/g, and no residual organic solvents were detected. Benzoic acid and monocrotophos were chosen as internal standards for H-qNMR and P-qNMR, respectively. The purity of the TnPP CRM was assessed as 994.6 mg/g, 994.1 mg/g, and 993.5 mg/g using MB, H-qNMR, and P-qNMR techniques, respectively. The verified purity of the TnPP CRM was ultimately determined to be 994.1 mg/g, with an expanded uncertainty of 3.4 mg/g (k = 2), ensuring traceability to the International System of Units (SI). This CRM can be effectively utilized for preparing calibration solutions suitable for the routine monitoring of TnPP residues in plastics and food samples.
PubMed: 38731466
DOI: 10.3390/molecules29091975 -
Molecules (Basel, Switzerland) Apr 2024It is a valid path to realize the zero discharge of coal chemical wastewater by using the fractional crystallization method to recycle the miscellaneous salt in...
Influence of Organic Impurities on Fractional Crystallization of NaCl and NaSO from High-Salinity Coal Chemical Wastewater: Thermodynamics and Nucleation Kinetics Analysis.
It is a valid path to realize the zero discharge of coal chemical wastewater by using the fractional crystallization method to recycle the miscellaneous salt in high-salinity wastewater. In this study, the thermodynamics and nucleation kinetics of sodium chloride (NaCl) and sodium sulfate (NaSO) crystallization in coal chemical wastewater were systematically studied. Through analyses of solubility, metastable zone width, and induction period, it was found that the impurity dimethoxymethane would increase the solid-liquid interface energy and critical crystal size during the nucleation of NaSO. Ternary phase diagrams of the pseudo-ternary NaSO-NaCl-HO systems in simulated wastewater were plotted in the temperature range of 303.15 to 333.15 K, indicating that a co-ionization effect existed between NaCl and NaSO, and NaCl had a strong salting out effect on NaSO. Finally, the nucleation rate and growth rate of NaSO crystals under simulated wastewater conditions were determined by the intermittent dynamic method, and the crystallization kinetic models of NaSO were established. The crystallization nucleation of NaSO crystals was found to be secondary nucleation controlled by surface reactions. The basic theoretical research of crystallization in this study is expected to fundamentally promote the application of fractional crystallization to realize the resource utilization of high-salinity wastewater in the coal chemical industry.
PubMed: 38731419
DOI: 10.3390/molecules29091928 -
Journal of Chromatographic Science May 2024Betaxolol (Bx) is a selective β1 receptor blocker used in the treatment of hypertension and glaucoma. The aim of the present work was to demonstrate an approach...
Betaxolol (Bx) is a selective β1 receptor blocker used in the treatment of hypertension and glaucoma. The aim of the present work was to demonstrate an approach involving use of liquid chromatography (LC) and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS) for the simultaneous separation, identification and characterization of impurities and of degradation products of betaxolol without their isolation from the reaction mixtures. At optimum condition, and according to ICH guidelines, the limit of detection (LOD) and limit of quantification (LOQ) for Bx are found to be 5.46 and 16.54 μg mL-1, respectively. However, the LOD and LOQ for the major degradation product P6 were 2.15 and 6.53 μg mL-1. Betaxolol was subjected to hydrolytic (acidic and basic) and oxidative, stress conditions according to International Conference on Harmonization (ICH) guideline Q1A (R2), and as results, the drug was found to be labile in acidic, basic and oxidative stress conditions. Based on LC-ESI/MS analysis, the found results revealed that Bx decomposes in acidic, basic and oxidizing environments. All degradation products were identified with the help of their fragmentation pattern and the masses obtained upon the MS analysis.
PubMed: 38717216
DOI: 10.1093/chromsci/bmae025 -
Biotechnology Advances 2024Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long... (Review)
Review
Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long start-up time for establishing a stable process, the toxicity of accumulated volatile fatty acids and ammonia nitrogen to methanogens resulting in extremely low biogas productivities, and a large amount of impurities in biogas for upgrading thereafter with high cost. Microbial electrolysis cell (MEC) is a device developed for electrosynthesis from organic wastes by electroactive microorganisms, but MEC alone is not practical for production at large scales. When AD is integrated with MEC, not only can biogas production be enhanced substantially, but also upgrading of the biogas product performed in situ. In this critical review, the state-of-the-art progress in developing AD-MEC systems is commented, and fundamentals underlying methanogenesis and bioelectrochemical reactions, technological innovations with electrode materials and configurations, designs and applications of AD-MEC systems, and strategies for their enhancement, such as driving the MEC device by electricity that is generated by burning the biogas to improve their energy efficiencies, are specifically addressed. Moreover, perspectives and challenges for the scale up of AD-MEC systems are highlighted for in-depth studies in the future to further improve their performance.
Topics: Biofuels; Electrolysis; Anaerobiosis; Bioelectric Energy Sources; Bioreactors; Methane
PubMed: 38714276
DOI: 10.1016/j.biotechadv.2024.108372 -
ACS Omega Apr 2024Hydrogen sulfide (HS) is a very toxic, acidic, and odorous gas. In this study, a calcined zeolite was used to investigate the adsorption performance of HS. Among...
Hydrogen sulfide (HS) is a very toxic, acidic, and odorous gas. In this study, a calcined zeolite was used to investigate the adsorption performance of HS. Among particle size, calcination temperature and time calcination temperature and time had significant effects on the adsorption capacity of HS on the zeolite. The optimal calcination conditions for the zeolite were 332 °C, 1.8 h, and 10-20 mm size, and the maximum adsorption capacity of HS was approximately 6219 mg kg. Calcination could broaden the channels, remove the adsorbed gases and impurities on the surface of zeolites, and increase the average pore size and point of zero net charge. As the zeolite adsorbed to saturation, it could be regenerated at the temperatures between 200 and 350 °C for 0.5 h. Compared with the natural zeolite, the adsorption capacities of dimethyl disulfide, dimethyl sulfide, toluene, CHSH, CS, CO, and HS were significantly higher on the calcined zeolite, while the adsorption capacity of CH was lower on the calcined zeolite. A gas treatment system by a temperature swing adsorption-regeneration process on honeycomb rotors with calcined zeolites was proposed. These findings are helpful for developing techniques for removing gas pollutants such as volatile sulfur compounds and volatile organic compounds to purify biogas and to limited toxic concentrations in the working environment.
PubMed: 38708253
DOI: 10.1021/acsomega.4c00987 -
Environmental Science and Pollution... May 2024Inorganic elements are added to toys as impurities to give desired stability, brightness, flexibility, and color; however, these elements may cause numerous health...
Inorganic elements are added to toys as impurities to give desired stability, brightness, flexibility, and color; however, these elements may cause numerous health issues after acute or chronic exposure. In this study, the inorganic profile of 14 elements (Al, As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni, Se, Sb, Pb, and Zn) in 63 toy makeup products was identified by inductively coupled plasma-mass spectrometry after microwave acid digestion method. Additionally, organic allergen fragrance was investigated by gas chromatography-mass spectrometry. The systemic exposure dosage (SED), margin of safety (MoS), lifetime cancer risk (LCR), hazard quotient (HQ), and hazard indices were used to assess the safety evaluation. Then, 57 out of 63 samples (90.48%) exceeded the limits at least for one toxic element with descending order Ni > Cr > Co > Pb > Sb > Cd > As > Hg. The SED values were compared with tolerable daily intake values and remarkably differences were found for Al and Pb. The MoS values for 57.15% of samples exceeded the limit value for Al, As, Cd, Co, Hg, Mn, Sb, and Zn elements. The LCR values were observed at 100% (n = 63), 79.37% (n = 50), 85.71% (n = 54), 77.78% (n = 49), and 18.87% (n = 10) for Cr, Ni, As, Pb, and Cd, respectively. Also, the skin sensitization risks were obtained for Cr and Ni at 26.980% (n = 17) and 9.52% (n = 6), respectively. The HQ values for 80% of samples were found to be ≥ 1 at least for one parameter. The investigation of fragrance allergens in samples did not show any significant ingredients. As a result, toy makeup products marketed in local stores were found to be predominantly unsafe. Children should be protected from harmful chemicals by regular monitoring and strict measures.
Topics: Humans; Play and Playthings; Child; Child Health; Risk Assessment
PubMed: 38696006
DOI: 10.1007/s11356-024-33362-2 -
Nanoscale Jun 2024Reproducibility issues resulting from particle growth solutions made with cetyltrimethylammonium bromide (CTAB) surfactant from different lots and product lines in a...
Reproducibility issues resulting from particle growth solutions made with cetyltrimethylammonium bromide (CTAB) surfactant from different lots and product lines in a newly developed synthesis of monometallic palladium (Pd) tetrahexahedra (THH) nanoparticles are investigated a multi-pronged approach. Time-resolved electrochemical measurements of solution potential, variation of chemical parameters in colloidal synthesis, and correlation to electrodeposition syntheses are used together to uncover the effects of the unknown contaminants on the chemical reducing environment during nanoparticle growth. Iodide-a known impurity in commercial CTAB-is identified as one of the required components for equalizing the reducing environment across multiple CTAB sources. However, an additional component-acetone-is critical to establishing the growth kinetics necessary to enable the reproducible synthesis of THH in each of the CTAB formulations. In one CTAB variety, the powdered surfactant contains too much acetone, and drying of the as-received surfactant and re-addition of solvent is necessary for successful Pd THH synthesis. The relevance of solvent impurities to the reducing environment in aqueous nanoparticle synthesis is confirmed electrochemical measurement approaches and solvent addition experiments. This work highlights the utility of real-time electrochemical potential measurements as a tool for benchmarking of nanoparticle syntheses and troubleshooting of reproducibility issues. The results additionally emphasize the importance of considering organic solvent impurities in powdered commercial reagents as a possible shape-determining factor during shaped nanomaterials synthesis.
PubMed: 38691093
DOI: 10.1039/d4nr00070f -
Journal of Peptide Science : An... Apr 2024In the present scenario, peptide is an emerging field of research having vast therapeutic applications. Diverse impurities may rise from various stages of the synthesis...
In the present scenario, peptide is an emerging field of research having vast therapeutic applications. Diverse impurities may rise from various stages of the synthesis process and storage of the peptides. Because these contaminants may have an impact on the therapeutic safety and effectiveness of peptides in their approaching applications, they must be identified and carefully monitored. Considering the pharmaceutical importance of the extent of peptides, we were motivated to synthesize a decapeptide and establish a novel gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method for its analysis along with efficient separation of its six related impurities. Different buffers, organic modifiers, and columns were used in the tests for good separation of these impurities. To establish a stability-indicating method, a stress study was also conducted. The International Conference on Harmonization (ICH) guidelines have been followed for validation of the developed analytical method. The validated method revealed sufficient accuracy, specificity, linearity, robustness, precision, and high sensitivity for its intended use. The proposed method could be appropriate for routine analysis and stability assessment of the decapeptide, which might be useful for further scientific investigation.
PubMed: 38689387
DOI: 10.1002/psc.3610