Pub Date : 2023-12-25DOI: 10.3390/separations11010009
P. Kousi, Dimitra-Artemis Strongyli, P. Tsakiridis, A. Hatzikioseyian, E. Remoundaki
This work presents a biological remediation process for molybdenum-bearing wastewater which may lead to the fabrication of biogenic Mo chalcogenide particles with (photo)catalytic properties. The process is based on dissimilatory sulphate reduction, utilising sulphate-reducing bacteria (SRB), and reductive precipitation of molybdate which is the predominant species of molybdenum in oxygenated water/wastewater. The SRB culture was established in a biofilm reactor which was fed with synthetic solutions containing sulphate (17.7 mM), molybdate molybdenum (2 mM), divalent iron (1.7 mM) and ethanol as the carbon/electron donor. The performance of the bioreactor was monitored in terms of pH, sulphate and molybdenum (Mo(VI) and total) content. The presence of thiomolybdate species was studied by scanning UV-Vis absorbance of samples from the reactor outflow while the reactor precipitates were studied via electron microscopy coupled with energy dispersive spectrometry, X-ray diffractometry and laser light scattering. A molar molybdate/sulphate ratio of 1:12.5 proved effective for molybdate reduction and recovery by 76% in 96 h, whereas sulphate was reduced by 57%. Molybdenum was immobilised in the sulphidic precipitates of the bioreactor, presumably via two principal mechanisms: (i) microbially mediated reduction and precipitation, and (ii) thiomolybdate formation and sorption/incorporation into iron sulphides.
{"title":"Immobilisation of Molybdenum in a Sulphate-Reducing Bioreactor","authors":"P. Kousi, Dimitra-Artemis Strongyli, P. Tsakiridis, A. Hatzikioseyian, E. Remoundaki","doi":"10.3390/separations11010009","DOIUrl":"https://doi.org/10.3390/separations11010009","url":null,"abstract":"This work presents a biological remediation process for molybdenum-bearing wastewater which may lead to the fabrication of biogenic Mo chalcogenide particles with (photo)catalytic properties. The process is based on dissimilatory sulphate reduction, utilising sulphate-reducing bacteria (SRB), and reductive precipitation of molybdate which is the predominant species of molybdenum in oxygenated water/wastewater. The SRB culture was established in a biofilm reactor which was fed with synthetic solutions containing sulphate (17.7 mM), molybdate molybdenum (2 mM), divalent iron (1.7 mM) and ethanol as the carbon/electron donor. The performance of the bioreactor was monitored in terms of pH, sulphate and molybdenum (Mo(VI) and total) content. The presence of thiomolybdate species was studied by scanning UV-Vis absorbance of samples from the reactor outflow while the reactor precipitates were studied via electron microscopy coupled with energy dispersive spectrometry, X-ray diffractometry and laser light scattering. A molar molybdate/sulphate ratio of 1:12.5 proved effective for molybdate reduction and recovery by 76% in 96 h, whereas sulphate was reduced by 57%. Molybdenum was immobilised in the sulphidic precipitates of the bioreactor, presumably via two principal mechanisms: (i) microbially mediated reduction and precipitation, and (ii) thiomolybdate formation and sorption/incorporation into iron sulphides.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"24 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139158043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-23DOI: 10.3390/separations11010007
Wei Jiang, Jilai Xue, Kaixi Jiang, Xunxiong Jiang, Shengdong Wang, Jinping Hu, Derek O Northwood, K. E. Waters, Hao Ma
Sulfuric acid curing and leaching is a promising technology for treating refractory ores. In this work, a refractory concentrate containing 3191 ppm uranium (U), 2135 ppm niobium (Nb), and 0.7% rare earth minerals (REMs) went through two stages: curing by high-concentration H2SO4 and leaching by low-concentration H2SO4. We investigated the behavior of those valuable metals during the two stages. For both curing and leaching, the operating parameters include the acid-to-solid ratio, time, temperature, and H2SO4 concentration. The recovery for U, Nb, and REMs was as high as 95%, 86%, and 73.5% using a curing acid-to-solid ratio of 1:1, curing temperature of 200 °C, curing time of 1 h, H2SO4 concentration of 98%, leaching liquid-to-solid ratio of 4:1, leaching time of 2 h, leaching temperature of 60 °C, and leaching H2SO4 concentration of 5 g/L. A “sulfuric acid curing–leaching-U extraction by N235–Nb recovery by resin adsorption–REMs’ recovery by resin adsorption” method was implemented, where the overall U, Nb, and REMs’ recovery reached 93.1%, 84.5%, and 69.6%, respectively.
{"title":"Recovery of Valuable Metals from Polymetallic Refractory Concentrate by a Sulfuric Acid Curing and Leaching Method","authors":"Wei Jiang, Jilai Xue, Kaixi Jiang, Xunxiong Jiang, Shengdong Wang, Jinping Hu, Derek O Northwood, K. E. Waters, Hao Ma","doi":"10.3390/separations11010007","DOIUrl":"https://doi.org/10.3390/separations11010007","url":null,"abstract":"Sulfuric acid curing and leaching is a promising technology for treating refractory ores. In this work, a refractory concentrate containing 3191 ppm uranium (U), 2135 ppm niobium (Nb), and 0.7% rare earth minerals (REMs) went through two stages: curing by high-concentration H2SO4 and leaching by low-concentration H2SO4. We investigated the behavior of those valuable metals during the two stages. For both curing and leaching, the operating parameters include the acid-to-solid ratio, time, temperature, and H2SO4 concentration. The recovery for U, Nb, and REMs was as high as 95%, 86%, and 73.5% using a curing acid-to-solid ratio of 1:1, curing temperature of 200 °C, curing time of 1 h, H2SO4 concentration of 98%, leaching liquid-to-solid ratio of 4:1, leaching time of 2 h, leaching temperature of 60 °C, and leaching H2SO4 concentration of 5 g/L. A “sulfuric acid curing–leaching-U extraction by N235–Nb recovery by resin adsorption–REMs’ recovery by resin adsorption” method was implemented, where the overall U, Nb, and REMs’ recovery reached 93.1%, 84.5%, and 69.6%, respectively.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"23 6","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139162643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polysaccharides are the main nutritional constituents in the Armillaria mellea fruiting bodies. The structure and immunoactivity of Armillaria mellea polysaccharide are valuable to be determined for development. In the present study, two polysaccharides, including Armillaria mellea neutral polysaccharide (AMPN) and Armillaria mellea acidic polysaccharide (AMPA), were prepared and determined. AMPN and AMPA were separated and refined by the ion exchange column and gel chromatographycolumn. Analysis of AMPN and AMPA revealed molecular weights of 4.432 × 103 Da and 7.323 × 103 Da. The monosaccharide composition analysis revealed that AMPN was mainly composed of 68.3%glucose, while AMPA consisted primarily of glucose, mannose, and galactose, accompanied by 8.9% galacturonic acid and 3% fucose. Then, infrared spectra analysis, Congo red staining, methylation, and NMR spectroscopy analysis were conducted as a means to clarify the structure of AMPN and AMPA. The NMR spectra demonstrated that the two polysaccharides included both α and β-configuration glycosidic bonds. The Congo red experiment suggests that AMPN and AMPA all had obvious triple helix structures.The effects of AMPN and AMPA on immune repair ability were compared by immune deficiency mice. The activity experiment showed that AMPN and acidic polysaccharides extracted from the Armillaria fruiting body have biological immune activity. Among them, AMPA showed higher immune activity. These findings suggest that Armillaria mellea fruiting bodies may be used as a source of dietary supplements and functional products.
{"title":"Structure Elucidation and Immunoactivity Study of Armillaria mellea Fruiting Body Polysaccharides","authors":"Qingqing Li, Ying Li, Huazhou Niu, Enhui Wang, Lili Jiao, Hui Li, Wei Wu","doi":"10.3390/separations11010003","DOIUrl":"https://doi.org/10.3390/separations11010003","url":null,"abstract":"Polysaccharides are the main nutritional constituents in the Armillaria mellea fruiting bodies. The structure and immunoactivity of Armillaria mellea polysaccharide are valuable to be determined for development. In the present study, two polysaccharides, including Armillaria mellea neutral polysaccharide (AMPN) and Armillaria mellea acidic polysaccharide (AMPA), were prepared and determined. AMPN and AMPA were separated and refined by the ion exchange column and gel chromatographycolumn. Analysis of AMPN and AMPA revealed molecular weights of 4.432 × 103 Da and 7.323 × 103 Da. The monosaccharide composition analysis revealed that AMPN was mainly composed of 68.3%glucose, while AMPA consisted primarily of glucose, mannose, and galactose, accompanied by 8.9% galacturonic acid and 3% fucose. Then, infrared spectra analysis, Congo red staining, methylation, and NMR spectroscopy analysis were conducted as a means to clarify the structure of AMPN and AMPA. The NMR spectra demonstrated that the two polysaccharides included both α and β-configuration glycosidic bonds. The Congo red experiment suggests that AMPN and AMPA all had obvious triple helix structures.The effects of AMPN and AMPA on immune repair ability were compared by immune deficiency mice. The activity experiment showed that AMPN and acidic polysaccharides extracted from the Armillaria fruiting body have biological immune activity. Among them, AMPA showed higher immune activity. These findings suggest that Armillaria mellea fruiting bodies may be used as a source of dietary supplements and functional products.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"81 19","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138954488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.3390/separations11010005
Monica Moroni
In recent decades, the versatility of fossil-based polymers has led them to become one of the most used materials for the production of several consumer goods. The destiny of post-consumer plastics is crucial for environmental sustainability. Two are the alternatives to landfilling: (i) energy recovery, i.e., replacement of traditional fuel with plastic litter, and (ii) recycling, i.e., processing of plastic wastes to produce secondary raw materials that may substitute primary raw materials. This work presents the investigation of a device for the hydraulic separation of heterogeneous plastic wastes, which, when properly upscaled, may be efficiently used within recycling plants. This apparatus is suitable for the separation of granules or flakes of plastics with a density higher than 1000 Kg/m3 and may replace existing technologies for mechanical recycling. The purpose of the device is to separate the useful fraction from a mixture of plastics and water introduced inside. The separation procedure efficacy relies on the difference in density, dimension, and shape of the processed plastic particles and on the flow features within the device. Experiments were carried out to test the efficacy of the device as a function of those factors. To increase the range of variation in the key parameters influencing the apparatus’s working principles, Computational Fluid Dynamics was employed to build a numerical model of the device. The validated numerical model suitable to fully characterize the apparatus performance features a hybrid grid with an inner mesh of 3·10−3 m size, a careful modeling of the near-wall region, and the k-ω SST turbulent model.
{"title":"Investigation of a Hydraulic Channel for Plastic Particles Sorting via Experimental and Numerical Tools","authors":"Monica Moroni","doi":"10.3390/separations11010005","DOIUrl":"https://doi.org/10.3390/separations11010005","url":null,"abstract":"In recent decades, the versatility of fossil-based polymers has led them to become one of the most used materials for the production of several consumer goods. The destiny of post-consumer plastics is crucial for environmental sustainability. Two are the alternatives to landfilling: (i) energy recovery, i.e., replacement of traditional fuel with plastic litter, and (ii) recycling, i.e., processing of plastic wastes to produce secondary raw materials that may substitute primary raw materials. This work presents the investigation of a device for the hydraulic separation of heterogeneous plastic wastes, which, when properly upscaled, may be efficiently used within recycling plants. This apparatus is suitable for the separation of granules or flakes of plastics with a density higher than 1000 Kg/m3 and may replace existing technologies for mechanical recycling. The purpose of the device is to separate the useful fraction from a mixture of plastics and water introduced inside. The separation procedure efficacy relies on the difference in density, dimension, and shape of the processed plastic particles and on the flow features within the device. Experiments were carried out to test the efficacy of the device as a function of those factors. To increase the range of variation in the key parameters influencing the apparatus’s working principles, Computational Fluid Dynamics was employed to build a numerical model of the device. The validated numerical model suitable to fully characterize the apparatus performance features a hybrid grid with an inner mesh of 3·10−3 m size, a careful modeling of the near-wall region, and the k-ω SST turbulent model.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"33 9","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.3390/separations11010004
Tianyang Hao, Lingyang Fan, Yiyue Chang, Hui Yang, Kai He
Myrica rubra (Lour.) Siebold & Zucc bark is a traditional natural medicine used by the people of the Dong minority in western Hunan in China. In this study, the main compounds in Myrica rubra bark including epigallocatechin gallate, myricetrin, myricetin, taraxerol, myricanol, and 11-O-acetylmyricanol were separated using both silica gel column chromatography and high-speed countercurrent chromatography (HSCCC). Notably, it is the first report of discovering 11-O-acetylmyricanol from Myrica rubra bark. The results of the bioactivity studies suggested that epigallocatechin gallate showed the highest α-glucosidase inhibitory activity, while myricetin exhibited the highest reactive oxygen species (ROS) scavenging ability in zebrafish embryos. Intriguingly, myricanol exhibited strong apoptosis-inducing activity on HepG2 cells, and further studies revealed that myricanol was capable of promoting the cleavage of caspase 3, 8, and 9, then resulting in the apoptosis in HepG2 cells. The findings of the present study have important implications for the separation of the main compounds in Myrica rubra and will provide credence to the ethnomedicinal application of the isolated compounds against cardiovascular disease and cancer.
{"title":"Separation and Biological Activities of the Main Compounds from the Bark of Myrica rubra Siebold & Zucc","authors":"Tianyang Hao, Lingyang Fan, Yiyue Chang, Hui Yang, Kai He","doi":"10.3390/separations11010004","DOIUrl":"https://doi.org/10.3390/separations11010004","url":null,"abstract":"Myrica rubra (Lour.) Siebold & Zucc bark is a traditional natural medicine used by the people of the Dong minority in western Hunan in China. In this study, the main compounds in Myrica rubra bark including epigallocatechin gallate, myricetrin, myricetin, taraxerol, myricanol, and 11-O-acetylmyricanol were separated using both silica gel column chromatography and high-speed countercurrent chromatography (HSCCC). Notably, it is the first report of discovering 11-O-acetylmyricanol from Myrica rubra bark. The results of the bioactivity studies suggested that epigallocatechin gallate showed the highest α-glucosidase inhibitory activity, while myricetin exhibited the highest reactive oxygen species (ROS) scavenging ability in zebrafish embryos. Intriguingly, myricanol exhibited strong apoptosis-inducing activity on HepG2 cells, and further studies revealed that myricanol was capable of promoting the cleavage of caspase 3, 8, and 9, then resulting in the apoptosis in HepG2 cells. The findings of the present study have important implications for the separation of the main compounds in Myrica rubra and will provide credence to the ethnomedicinal application of the isolated compounds against cardiovascular disease and cancer.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"254 21","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139170615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.3390/separations11010006
Mehedi Hasan, L. Anh, T. Xuan
This is the first study aiming to enrich momilactones A (MA) and B (MB) and phenolic compounds in germinated brown rice (GBR) and non-GBR var. Koshihikari and Milky Queen through the cooking process. Extraction methods for these compounds were optimized by applying various conditions, including solvents (80% methanol and 80% ethanol), heat (80 °C), and sonication (2 h). Momilactone and phenolic quantities were determined by ultra-performance liquid chromatography–electrospray ionization mass spectrometry (UPLC–ESI-MS) and high-performance liquid chromatography (HPLC), respectively. Accordingly, cooked Koshihikari GBR extract using 80% methanol and sonication (GKB4) revealed the highest amounts of tricin, caffeic, ρ-hydroxybenzoic, ρ-coumaric, ferulic, salicylic, and cinnamic acids (1.71, 1.01, 0.62, 0.45, 0.94, 2.50, and 0.37 mg/g DW, respectively), consistent with the strongest antiradical activities in DPPH and ABTS assays (IC50 = 1.47 and 1.70 mg/mL, respectively). Non-cooked GBR Koshihikari extract using 80% ethanol and sonication (GKB9) exhibited the highest MA and MB contents (147.73 and 118.8 μg/g DW, respectively). Notably, GKB9 showed potent inhibition of α-amylase and α-glucosidase (IC50 = 0.48 and 0.15 mg/mL, respectively), compared with the anti-diabetic drug acarbose (IC50 = 0.26 and 2.48 mg/mL, respectively). The findings hold significant implications for developing phenolic- and momilactone-enriched brown rice with health-beneficial properties.
{"title":"Momilactones and Phenolics in Brown Rice: Enrichment, Optimized Extraction, and Potential for Antioxidant and Anti-Diabetic Activities","authors":"Mehedi Hasan, L. Anh, T. Xuan","doi":"10.3390/separations11010006","DOIUrl":"https://doi.org/10.3390/separations11010006","url":null,"abstract":"This is the first study aiming to enrich momilactones A (MA) and B (MB) and phenolic compounds in germinated brown rice (GBR) and non-GBR var. Koshihikari and Milky Queen through the cooking process. Extraction methods for these compounds were optimized by applying various conditions, including solvents (80% methanol and 80% ethanol), heat (80 °C), and sonication (2 h). Momilactone and phenolic quantities were determined by ultra-performance liquid chromatography–electrospray ionization mass spectrometry (UPLC–ESI-MS) and high-performance liquid chromatography (HPLC), respectively. Accordingly, cooked Koshihikari GBR extract using 80% methanol and sonication (GKB4) revealed the highest amounts of tricin, caffeic, ρ-hydroxybenzoic, ρ-coumaric, ferulic, salicylic, and cinnamic acids (1.71, 1.01, 0.62, 0.45, 0.94, 2.50, and 0.37 mg/g DW, respectively), consistent with the strongest antiradical activities in DPPH and ABTS assays (IC50 = 1.47 and 1.70 mg/mL, respectively). Non-cooked GBR Koshihikari extract using 80% ethanol and sonication (GKB9) exhibited the highest MA and MB contents (147.73 and 118.8 μg/g DW, respectively). Notably, GKB9 showed potent inhibition of α-amylase and α-glucosidase (IC50 = 0.48 and 0.15 mg/mL, respectively), compared with the anti-diabetic drug acarbose (IC50 = 0.26 and 2.48 mg/mL, respectively). The findings hold significant implications for developing phenolic- and momilactone-enriched brown rice with health-beneficial properties.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"3 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monosaccharide composition analysis is essential to the structural characterization and research into the biological activity of polysaccharides. In this study, a systematic comparison was performed among commonly used monosaccharide composition analysis methods, including colorimetric and chromatographic methods. These were tested on 16 aldoses, ketoses, alditols, amino sugars, and uronic acids. Furthermore, the effect of hydrolysis methods was also investigated. The results showed that the phenol sulfuric acid method is greatly affected by the type of monosaccharide that is used as the reference substance. The determination of uronic acid using sulfuric acid carbazole is less affected by neutral sugars than that method using m-hydroxybiphenyl. The high-performance thin-layer chromatography (HPTLC) method can simultaneously analyze multiple samples and accurately determine the type of uronic acid. High-performance liquid chromatography (HPLC) can provide a good qualitative and quantitative analysis of aldose, amino sugars, and uronic acids, while gas chromatography–mass spectrometry (GC-MS) can detect aldose, ketose, and alditols. Fructose was detected in a large amount in inulin and Codonopsis pilosula after one-step hydrolysis, while it was totally destroyed in two-step hydrolysis. The release of galacturonic acid significantly increased after two-step hydrolysis in pectin and Lycium barbarum, which indicated that one-step hydrolysis is not enough for acidic polysaccharides. The results of this study are beneficial for selecting appropriate hydrolysis and analysis methods in order to accurately analyze the monosaccharide compositions of natural polysaccharides.
{"title":"Effects of Hydrolysis Condition and Detection Method on the Monosaccharide Composition Analysis of Polysaccharides from Natural Sources","authors":"Meijuan Zhao, Fengyan Kuang, Yingyue Zhang, Guang-Ping Lv","doi":"10.3390/separations11010002","DOIUrl":"https://doi.org/10.3390/separations11010002","url":null,"abstract":"Monosaccharide composition analysis is essential to the structural characterization and research into the biological activity of polysaccharides. In this study, a systematic comparison was performed among commonly used monosaccharide composition analysis methods, including colorimetric and chromatographic methods. These were tested on 16 aldoses, ketoses, alditols, amino sugars, and uronic acids. Furthermore, the effect of hydrolysis methods was also investigated. The results showed that the phenol sulfuric acid method is greatly affected by the type of monosaccharide that is used as the reference substance. The determination of uronic acid using sulfuric acid carbazole is less affected by neutral sugars than that method using m-hydroxybiphenyl. The high-performance thin-layer chromatography (HPTLC) method can simultaneously analyze multiple samples and accurately determine the type of uronic acid. High-performance liquid chromatography (HPLC) can provide a good qualitative and quantitative analysis of aldose, amino sugars, and uronic acids, while gas chromatography–mass spectrometry (GC-MS) can detect aldose, ketose, and alditols. Fructose was detected in a large amount in inulin and Codonopsis pilosula after one-step hydrolysis, while it was totally destroyed in two-step hydrolysis. The release of galacturonic acid significantly increased after two-step hydrolysis in pectin and Lycium barbarum, which indicated that one-step hydrolysis is not enough for acidic polysaccharides. The results of this study are beneficial for selecting appropriate hydrolysis and analysis methods in order to accurately analyze the monosaccharide compositions of natural polysaccharides.","PeriodicalId":21833,"journal":{"name":"Separations","volume":" 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.3390/separations11010001
Francisco José Alguacil
Since CO2 is an important component of gas emissions, its removal from gas streams is of the utmost importance to fulfill various environmental requirements. The technologies used to accomplish this removal are based mainly on absorption, as well as adsorption and membrane processing. Among the materials used in the above separation processes, materials in nano forms offer a potential alternative to other commonly used macromaterials. The present work reviews the most recent publications (2023) about CO2 capture using different nanomaterials, and whilst most of these publications were dedicated to investigating the above, several presented data on the separation of CO2 from other gases, namely nitrogen and methane. Furthermore, a number of publications investigated the recyclability of nanomaterials under continuous use, and just three of the references were about computational modeling; all others were experimental papers, and only one reference used a real industrial gas.
{"title":"Nanomaterials for CO2 Capture from Gas Streams","authors":"Francisco José Alguacil","doi":"10.3390/separations11010001","DOIUrl":"https://doi.org/10.3390/separations11010001","url":null,"abstract":"Since CO2 is an important component of gas emissions, its removal from gas streams is of the utmost importance to fulfill various environmental requirements. The technologies used to accomplish this removal are based mainly on absorption, as well as adsorption and membrane processing. Among the materials used in the above separation processes, materials in nano forms offer a potential alternative to other commonly used macromaterials. The present work reviews the most recent publications (2023) about CO2 capture using different nanomaterials, and whilst most of these publications were dedicated to investigating the above, several presented data on the separation of CO2 from other gases, namely nitrogen and methane. Furthermore, a number of publications investigated the recyclability of nanomaterials under continuous use, and just three of the references were about computational modeling; all others were experimental papers, and only one reference used a real industrial gas.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"10 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138959970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-18DOI: 10.3390/separations10120602
Rana Salem Al Khulaifi, Mohammed Mousa Alshehri, Inas Al-Qadsy, Mona A. Al Jufareen, Waseem. Saeed, A. Badjah-Hadj-Ahmed, Taieb Aouak
A comparative study of a Schiff base reaction involving benzaldehyde and n-butylamine was carried out to improve the yield of the resulting imine. This reaction was carried out at different temperatures without and with the elimination of the water produced during the process by the pervaporation (PV) technique using a typical cylindrical cell. To reach this goal, different dense membranes made of crosslinked poly(vinyl alcohol) with different oxalic acid (crosslinker) contents were prepared by the solvent casting method. Different parameters influencing the performance of the membrane in the separation process including swellability, diffusivity, crosslinking density, and thermal properties were investigated. The total and partial cumulative transmembranar fluxes as well as the separation factor were studied and the separation process was monitored by HPLC analysis. The n-butyl-1-phenylmethanimine produced was characterized by FTIR and 1HNMR analyses. The results obtained were a clear improvement in the yield of the reaction. For example, the yield obtained from the Schiff base reaction occurring without assistance by PV varied from 58 to 84 wt% when the temperature changed from 5 to 45 °C. On the other hand, when the PV process was used to eliminate water from this reaction mixture, the yield went from 90.4 to 98.6% by weight in this same temperature order. The cumulative total and partial fluxes significantly decreased with time. On the other hand, the separation factor reached a maximum at about one hour at 5, 15, and 45 °C. At 25 °C, the maximum total flux was reached at about 2 h of the PV process. The best selectivity of the PVA-0.5 membrane with regard to water was obtained at 15 °C. It was also revealed from the results obtained that the cumulative total and partial flux decreased rapidly with time and the separation factor reached a maximum at one hour into the PV process, in which 1.51 × 104 was reached at 15 °C, 6.25 × 103 and 3.50 × 103 at one hour of the separation process, and 10.23 × 103 at 25 °C at 2 h of the water removal by PV.
{"title":"Breaking the Equilibrium and Improving the Yield of Schiff Base Reactions by Pervaporation: Application to a Reaction Involving n-butylamine and Benzaldehyde","authors":"Rana Salem Al Khulaifi, Mohammed Mousa Alshehri, Inas Al-Qadsy, Mona A. Al Jufareen, Waseem. Saeed, A. Badjah-Hadj-Ahmed, Taieb Aouak","doi":"10.3390/separations10120602","DOIUrl":"https://doi.org/10.3390/separations10120602","url":null,"abstract":"A comparative study of a Schiff base reaction involving benzaldehyde and n-butylamine was carried out to improve the yield of the resulting imine. This reaction was carried out at different temperatures without and with the elimination of the water produced during the process by the pervaporation (PV) technique using a typical cylindrical cell. To reach this goal, different dense membranes made of crosslinked poly(vinyl alcohol) with different oxalic acid (crosslinker) contents were prepared by the solvent casting method. Different parameters influencing the performance of the membrane in the separation process including swellability, diffusivity, crosslinking density, and thermal properties were investigated. The total and partial cumulative transmembranar fluxes as well as the separation factor were studied and the separation process was monitored by HPLC analysis. The n-butyl-1-phenylmethanimine produced was characterized by FTIR and 1HNMR analyses. The results obtained were a clear improvement in the yield of the reaction. For example, the yield obtained from the Schiff base reaction occurring without assistance by PV varied from 58 to 84 wt% when the temperature changed from 5 to 45 °C. On the other hand, when the PV process was used to eliminate water from this reaction mixture, the yield went from 90.4 to 98.6% by weight in this same temperature order. The cumulative total and partial fluxes significantly decreased with time. On the other hand, the separation factor reached a maximum at about one hour at 5, 15, and 45 °C. At 25 °C, the maximum total flux was reached at about 2 h of the PV process. The best selectivity of the PVA-0.5 membrane with regard to water was obtained at 15 °C. It was also revealed from the results obtained that the cumulative total and partial flux decreased rapidly with time and the separation factor reached a maximum at one hour into the PV process, in which 1.51 × 104 was reached at 15 °C, 6.25 × 103 and 3.50 × 103 at one hour of the separation process, and 10.23 × 103 at 25 °C at 2 h of the water removal by PV.","PeriodicalId":21833,"journal":{"name":"Separations","volume":" 31","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-18DOI: 10.3390/separations10120600
R. Koivula, Wenzhong Zhang
Metal(IV) phosphate and phosphonates materials have increasingly found their applications in water purification, heterogeneous catalysis, drug delivery, and proton-exchange membrane fuel cells. The strong linkage between tetravalent metal cations and phosphate/phosphonate groups offers a unique bottom-up design platform, resulting in chemically stable inorganics or hybrids. Task-specific physiochemical functionalities could be deposited by modifying the phosphate/phosphonate groups before the material synthesis. The high reactivity between the metal centre and the phosphorus-containing linker, on the other hand, often leads to obtaining unordered materials (amorphous solids or coordination polymers). The chemical composition of the prepared materials is a key parameter in guiding the synthetic approach and in governing their performances. This narrative review focuses on critically summarising the traditional and advanced analytical methods for probing the composition of these materials. The reader is introduced to and guided on the advances and restrictions of different analysis techniques when probing metal(IV) phosphates/phosphonates. Both solution-based and solid-state spectroscopic techniques are covered with a focus on understanding the quantity and the linkage status of the phosphorus-containing moieties. These techniques include atomic spectroscopy, mass spectroscopy, nuclear magnetic resonance spectroscopy, X-ray-based methods, and neutron activation analysis.
金属（IV）磷酸盐和膦酸盐材料越来越多地应用于水净化、异相催化、药物输送和质子交换膜燃料电池。四价金属阳离子与磷酸盐/膦酸盐基团之间的强联系提供了一个独特的自下而上的设计平台，从而产生了化学性质稳定的无机物或混合物。在材料合成之前，可以通过修改磷酸盐/膦酸盐基团来沉积特定任务的理化功能。另一方面，金属中心和含磷连接体之间的高反应性往往会导致获得无序材料（无定形固体或配位聚合物）。所制备材料的化学成分是指导合成方法及其性能的关键参数。这篇叙述性综述着重批判性地总结了探测这些材料成分的传统和先进分析方法。在探究金属(IV)磷酸盐/膦酸盐时，将向读者介绍并指导不同分析技术的进步和限制。本书涵盖了溶液光谱和固态光谱技术，重点是了解含磷分子的数量和连接状态。这些技术包括原子光谱、质谱、核磁共振光谱、基于 X 射线的方法和中子活化分析。
{"title":"Compositional Analysis of Metal(IV) Phosphate and Phosphonate Materials—Pitfalls and Best Practices","authors":"R. Koivula, Wenzhong Zhang","doi":"10.3390/separations10120600","DOIUrl":"https://doi.org/10.3390/separations10120600","url":null,"abstract":"Metal(IV) phosphate and phosphonates materials have increasingly found their applications in water purification, heterogeneous catalysis, drug delivery, and proton-exchange membrane fuel cells. The strong linkage between tetravalent metal cations and phosphate/phosphonate groups offers a unique bottom-up design platform, resulting in chemically stable inorganics or hybrids. Task-specific physiochemical functionalities could be deposited by modifying the phosphate/phosphonate groups before the material synthesis. The high reactivity between the metal centre and the phosphorus-containing linker, on the other hand, often leads to obtaining unordered materials (amorphous solids or coordination polymers). The chemical composition of the prepared materials is a key parameter in guiding the synthetic approach and in governing their performances. This narrative review focuses on critically summarising the traditional and advanced analytical methods for probing the composition of these materials. The reader is introduced to and guided on the advances and restrictions of different analysis techniques when probing metal(IV) phosphates/phosphonates. Both solution-based and solid-state spectroscopic techniques are covered with a focus on understanding the quantity and the linkage status of the phosphorus-containing moieties. These techniques include atomic spectroscopy, mass spectroscopy, nuclear magnetic resonance spectroscopy, X-ray-based methods, and neutron activation analysis.","PeriodicalId":21833,"journal":{"name":"Separations","volume":"34 S138","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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