Pub Date : 2020-07-29DOI: 10.1080/15422119.2020.1797792
Jie Zhang, Ling Gao, Jie Hu, Chong Wang, P. Hagedoorn, Ning Li, Xing-yu Zhou
ABSTRACT Hypericin is a naturally occurring compound synthesized by certain species of the genus Hypericum, with various pharmacological effects. It is used as a natural photosensitizing agent with great potential in photodynamic therapy. This review discusses the latest results about the biosynthetic pathways and chemical synthetic routes to obtain hypericin. Although many analysis methods can be used for the determination of hypericin purity, HPLC has become the method of choice due to its fast and sensitive analyses. The extraction and purification of hypericin are also described. Hypericin can be used as a photosensitizer due to a large and active π-electron conjugated system in its structure. Medical applications of hypericin are not easy due to several unsolved practical problems, which include hypericin phototoxicity, poor solubility in water, and extreme sensitivity to light, heat, and pH.
{"title":"Hypericin: Source, Determination, Separation, and Properties","authors":"Jie Zhang, Ling Gao, Jie Hu, Chong Wang, P. Hagedoorn, Ning Li, Xing-yu Zhou","doi":"10.1080/15422119.2020.1797792","DOIUrl":"https://doi.org/10.1080/15422119.2020.1797792","url":null,"abstract":"ABSTRACT Hypericin is a naturally occurring compound synthesized by certain species of the genus Hypericum, with various pharmacological effects. It is used as a natural photosensitizing agent with great potential in photodynamic therapy. This review discusses the latest results about the biosynthetic pathways and chemical synthetic routes to obtain hypericin. Although many analysis methods can be used for the determination of hypericin purity, HPLC has become the method of choice due to its fast and sensitive analyses. The extraction and purification of hypericin are also described. Hypericin can be used as a photosensitizer due to a large and active π-electron conjugated system in its structure. Medical applications of hypericin are not easy due to several unsolved practical problems, which include hypericin phototoxicity, poor solubility in water, and extreme sensitivity to light, heat, and pH.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"5 1","pages":"1 - 10"},"PeriodicalIF":0.0,"publicationDate":"2020-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89022285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-20DOI: 10.1080/15422119.2020.1792930
M. Asadollahzadeh, R. Torkaman, M. Torab‐Mostaedi
ABSTRACT Strategic elements, such as rare earth elements, play a critical part in industry, especially in the production of high-tech materials. Major global industries developed a strong dependence on rare earth materials. Every year, innovations appear in sectors such as modern technology, green energy, or communication technologies needing more strategic metals to increase in the investment profitability. One of the effective extraction methods for rare earth metals in low concentrations is the adsorption process. It has a high selectivity and high efficiency reducing the volume of pollutants in the environment. Many adsorbents from simple materials in nature to complex nanocomposite materials have been described in the literature. In this review, the research works with various adsorbent materials have been described for the extraction and separation of rare earth elements from aqueous solutions or wastewater. In addition, the extraction efficiency of the developed adsorbents is discussed. The trend is illustrated in the application of new materials with high adsorption capacity for the production of rare earth elements.
{"title":"Extraction and Separation of Rare Earth Elements by Adsorption Approaches: Current Status and Future Trends","authors":"M. Asadollahzadeh, R. Torkaman, M. Torab‐Mostaedi","doi":"10.1080/15422119.2020.1792930","DOIUrl":"https://doi.org/10.1080/15422119.2020.1792930","url":null,"abstract":"ABSTRACT Strategic elements, such as rare earth elements, play a critical part in industry, especially in the production of high-tech materials. Major global industries developed a strong dependence on rare earth materials. Every year, innovations appear in sectors such as modern technology, green energy, or communication technologies needing more strategic metals to increase in the investment profitability. One of the effective extraction methods for rare earth metals in low concentrations is the adsorption process. It has a high selectivity and high efficiency reducing the volume of pollutants in the environment. Many adsorbents from simple materials in nature to complex nanocomposite materials have been described in the literature. In this review, the research works with various adsorbent materials have been described for the extraction and separation of rare earth elements from aqueous solutions or wastewater. In addition, the extraction efficiency of the developed adsorbents is discussed. The trend is illustrated in the application of new materials with high adsorption capacity for the production of rare earth elements.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"71 1","pages":"417 - 444"},"PeriodicalIF":0.0,"publicationDate":"2020-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76773219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-20DOI: 10.1080/15422119.2020.1789995
Z. Gao, Yaodong Wei, Zhongxin Liu, Chun-Xiao Jia, Juan Wang, J. Wang, Y. Mao
ABSTRACT Current studies on improving the separation performance of cyclone separators focus on five aspects: i] geometry-structure optimization, ii] geometry-parameter optimization, iii] operation-parameter optimization, iv] operating-condition optimization, and v] internal component optimization. Many scholars work on the design and use of internal components in a cyclone separator to solve various industrial problems, but they seldom systematically classify these internal components. In the last 1999–2019 years, reports on such classification were relatively rare. Compared to the other four aspects, the internal components optimization has a unique advantage: when the equipment operation fails, there is no need to replace the original equipment, just the defective component, which greatly saves both maintenance and engineering expenses. In this review, several kinds of internal cyclone components are systematically summarized and classified, including their mechanism and usage effect. Furthermore, the trends in internal component development have also been prospected. Combined applications, development of new components and applications of new materials are the three main trends. In the future, internal components will be more diversified, detailed, precise and simplified. Finally, we expect that these developments will not only improve the separation efficiency and reduce the pressure drop but also satisfy requirements in environmental protection and process security.
{"title":"Internal Components Optimization in Cyclone Separators: Systematic Classification and Meta-analysis","authors":"Z. Gao, Yaodong Wei, Zhongxin Liu, Chun-Xiao Jia, Juan Wang, J. Wang, Y. Mao","doi":"10.1080/15422119.2020.1789995","DOIUrl":"https://doi.org/10.1080/15422119.2020.1789995","url":null,"abstract":"ABSTRACT Current studies on improving the separation performance of cyclone separators focus on five aspects: i] geometry-structure optimization, ii] geometry-parameter optimization, iii] operation-parameter optimization, iv] operating-condition optimization, and v] internal component optimization. Many scholars work on the design and use of internal components in a cyclone separator to solve various industrial problems, but they seldom systematically classify these internal components. In the last 1999–2019 years, reports on such classification were relatively rare. Compared to the other four aspects, the internal components optimization has a unique advantage: when the equipment operation fails, there is no need to replace the original equipment, just the defective component, which greatly saves both maintenance and engineering expenses. In this review, several kinds of internal cyclone components are systematically summarized and classified, including their mechanism and usage effect. Furthermore, the trends in internal component development have also been prospected. Combined applications, development of new components and applications of new materials are the three main trends. In the future, internal components will be more diversified, detailed, precise and simplified. Finally, we expect that these developments will not only improve the separation efficiency and reduce the pressure drop but also satisfy requirements in environmental protection and process security.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"26 1","pages":"400 - 416"},"PeriodicalIF":0.0,"publicationDate":"2020-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74546931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-14DOI: 10.1080/15422119.2020.1789659
A. Salehi, M. Ghannadi‐Maragheh, M. Torab‐Mostaedi, R. Torkaman, M. Asadollahzadeh
ABSTRACT Water is the most abundant liquid on Earth, but only 2.5% of worldwide water are fresh. It is impossible to ignore the importance of water in almost every process on Earth, from the smallest bacteria life to the formation of the continents. Today, efforts for the desalination of seawater and brackish water are critical to produce drinking water. In recent years, a novel material: hydrogel, was considered in desalination processes. Interesting hydrogel applications were proposed for forward osmosis desalination, solar still, electrodialysis, and capacitive desalination. Simple and inexpensive desalination ways for drinking water production are needed. Hydrogel compounds are one of the leading options in such issue. The use of the hydrogel-based solar steam generator could produce drinkable water cheaper than other water desalination processes. The hydrogel classification is based on physical structure, ion charge, synthesis methods, particle size, chemical, and physical bonding, and mechanical properties. Therefore, this review summarizes the recent research progresses in the use of hydrogels for desalination and purified water production.
{"title":"Hydrogel materials as an emerging platform for desalination and the production of purified water","authors":"A. Salehi, M. Ghannadi‐Maragheh, M. Torab‐Mostaedi, R. Torkaman, M. Asadollahzadeh","doi":"10.1080/15422119.2020.1789659","DOIUrl":"https://doi.org/10.1080/15422119.2020.1789659","url":null,"abstract":"ABSTRACT Water is the most abundant liquid on Earth, but only 2.5% of worldwide water are fresh. It is impossible to ignore the importance of water in almost every process on Earth, from the smallest bacteria life to the formation of the continents. Today, efforts for the desalination of seawater and brackish water are critical to produce drinking water. In recent years, a novel material: hydrogel, was considered in desalination processes. Interesting hydrogel applications were proposed for forward osmosis desalination, solar still, electrodialysis, and capacitive desalination. Simple and inexpensive desalination ways for drinking water production are needed. Hydrogel compounds are one of the leading options in such issue. The use of the hydrogel-based solar steam generator could produce drinkable water cheaper than other water desalination processes. The hydrogel classification is based on physical structure, ion charge, synthesis methods, particle size, chemical, and physical bonding, and mechanical properties. Therefore, this review summarizes the recent research progresses in the use of hydrogels for desalination and purified water production.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"97 1","pages":"380 - 399"},"PeriodicalIF":0.0,"publicationDate":"2020-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79128330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-13DOI: 10.1080/15422119.2020.1784940
A. Ivaneev, M. Ermolin, P. Fedotov, S. Faucher, G. Lespes
ABSTRACT Theoretical background, instrumentation, and applications of “conventional” sedimentation field-flow fractionation in thin channels (SdFFF) and “non-conventional” sedimentation coiled-tube field-flow fractionation (CTFFF) in rotating columns are summarized and compared. Applications are classified into three main groups: environmental studies, material science, and biological studies. SdFFF is a versatile separation and sizing method applicable to complex particulate matter such as environmental samples, engineered particles, cells, etc. However, the mass of injected particles does not usually exceed 10–20 µg to avoid overloading. CTFFF enables the mass of the particulate sample to be increased up to grams. Despite its low resolution as compared to SdFFF, CTFFF has important niche applications. It opens a new door into the isolation of nano- and submicron particles from bulk samples of different origin and nature. In addition, CTFFF is a very promising instrument for the separation and purification of nano- and microparticles at preparative and even industrial scale. Abbreviations: A4F – Asymmetrical flow field-flow fractionation; CSF – Conventional SPLITT fractionation; CTFFF – Coiled-tube field-flow fractionation; CV-ETAAS – Cold vapor electrothermal atomic absorption spectroscopy; DLS – Dynamic light scattering; EDS – Energy dispersive X-ray spectroscopy; ES-SMPS – Electrospray-scanning mobility particle sizer; ETAAS – Electrothermal atomic absorption spectroscopy; FE – Fractionation efficiency; FFDSF – Full feed depletion SPLITT fractionation; FFF – Field-flow fractionation; ICP-AES – Inductively coupled plasma-atomic emission spectrometry; ICP-MS – Inductively coupled plasma-mass spectrometry; LD – Laser diffraction; MAD – Monoolein aqueous dispersions; MALS – Multi-angle light scattering; NLC – Nanostructured lipid carriers; NP – Nanoparticle; NTA – Nanoparticle tracking analysis; OM – Optical microscopy; PS – Polystyrene; PSD – Particle size distribution; RCC – Rotating coiled column; SdFFF – Sedimentation field-flow fractionation in thin channels; SEM – Scanning electron microscopy; SP-ICP-MS – Single-particle inductively coupled plasma-mass spectrometry; SPLITT – Split-flow thin-cell fractionation; TEM – Transmission electron microscopy; UV – Ultraviolet detector
{"title":"Sedimentation Field-flow Fractionation in Thin Channels and Rotating Coiled Columns: From Analytical to Preparative Scale Separations","authors":"A. Ivaneev, M. Ermolin, P. Fedotov, S. Faucher, G. Lespes","doi":"10.1080/15422119.2020.1784940","DOIUrl":"https://doi.org/10.1080/15422119.2020.1784940","url":null,"abstract":"ABSTRACT Theoretical background, instrumentation, and applications of “conventional” sedimentation field-flow fractionation in thin channels (SdFFF) and “non-conventional” sedimentation coiled-tube field-flow fractionation (CTFFF) in rotating columns are summarized and compared. Applications are classified into three main groups: environmental studies, material science, and biological studies. SdFFF is a versatile separation and sizing method applicable to complex particulate matter such as environmental samples, engineered particles, cells, etc. However, the mass of injected particles does not usually exceed 10–20 µg to avoid overloading. CTFFF enables the mass of the particulate sample to be increased up to grams. Despite its low resolution as compared to SdFFF, CTFFF has important niche applications. It opens a new door into the isolation of nano- and submicron particles from bulk samples of different origin and nature. In addition, CTFFF is a very promising instrument for the separation and purification of nano- and microparticles at preparative and even industrial scale. Abbreviations: A4F – Asymmetrical flow field-flow fractionation; CSF – Conventional SPLITT fractionation; CTFFF – Coiled-tube field-flow fractionation; CV-ETAAS – Cold vapor electrothermal atomic absorption spectroscopy; DLS – Dynamic light scattering; EDS – Energy dispersive X-ray spectroscopy; ES-SMPS – Electrospray-scanning mobility particle sizer; ETAAS – Electrothermal atomic absorption spectroscopy; FE – Fractionation efficiency; FFDSF – Full feed depletion SPLITT fractionation; FFF – Field-flow fractionation; ICP-AES – Inductively coupled plasma-atomic emission spectrometry; ICP-MS – Inductively coupled plasma-mass spectrometry; LD – Laser diffraction; MAD – Monoolein aqueous dispersions; MALS – Multi-angle light scattering; NLC – Nanostructured lipid carriers; NP – Nanoparticle; NTA – Nanoparticle tracking analysis; OM – Optical microscopy; PS – Polystyrene; PSD – Particle size distribution; RCC – Rotating coiled column; SdFFF – Sedimentation field-flow fractionation in thin channels; SEM – Scanning electron microscopy; SP-ICP-MS – Single-particle inductively coupled plasma-mass spectrometry; SPLITT – Split-flow thin-cell fractionation; TEM – Transmission electron microscopy; UV – Ultraviolet detector","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"1 1","pages":"363 - 379"},"PeriodicalIF":0.0,"publicationDate":"2020-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90379515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-02DOI: 10.1080/15422119.2018.1562942
Ramesh Kumar, A. K. Ghosh, P. Pal
Literature on biodiesel production over the last 10 years (2007–2018) has been critically reviewed directing further research toward membrane-based sustainable and green production. The manuscript discusses how biodiesel production strategies have evolved in the recent years through adoption of better feedstock, better catalysts, more efficient reactor technology, and through incorporation of more efficient downstream separation-purification techniques. The review reveals that though transesterification reaction between alcohol and plant oil/animal fats leading to production of biodiesel is simple, the downstream separation and purification of the final product (fatty acid methyl esters) is quite challenging. This review shows that productivity can be enhanced through new generation catalysts, use of green solvents, and a more efficient reactor technology while the use of tailor-made membrane in appropriate modules holds the promise of low-cost and eco-friendly downstream purification. It is exposed that a membrane-based technology can bring about high degree of process intensification, whereas recovery and reuse of catalysts and alcohol are likely to add to the economy of the process, resulting in sustainable production technology.
{"title":"Sustainable Production of Biofuels through Membrane-Integrated Systems","authors":"Ramesh Kumar, A. K. Ghosh, P. Pal","doi":"10.1080/15422119.2018.1562942","DOIUrl":"https://doi.org/10.1080/15422119.2018.1562942","url":null,"abstract":"Literature on biodiesel production over the last 10 years (2007–2018) has been critically reviewed directing further research toward membrane-based sustainable and green production. The manuscript discusses how biodiesel production strategies have evolved in the recent years through adoption of better feedstock, better catalysts, more efficient reactor technology, and through incorporation of more efficient downstream separation-purification techniques. The review reveals that though transesterification reaction between alcohol and plant oil/animal fats leading to production of biodiesel is simple, the downstream separation and purification of the final product (fatty acid methyl esters) is quite challenging. This review shows that productivity can be enhanced through new generation catalysts, use of green solvents, and a more efficient reactor technology while the use of tailor-made membrane in appropriate modules holds the promise of low-cost and eco-friendly downstream purification. It is exposed that a membrane-based technology can bring about high degree of process intensification, whereas recovery and reuse of catalysts and alcohol are likely to add to the economy of the process, resulting in sustainable production technology.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"90 1","pages":"207 - 228"},"PeriodicalIF":0.0,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83533077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-02DOI: 10.1080/15422119.2019.1581216
E. González-García, M. Marina, M. C. García
Protein sample preparation is the most critical step in protein analysis of complex samples and is constituted by tedious, time-consuming, and difficult-to-automate steps that usually involve the use of high volumes of solvents. In recent years, novel extraction or digestion nanomaterials (NMs) have been developed aiming to overcome these drawbacks. In this review, we have grouped the recent works related to the development of new NMs and their applications to the extraction, enrichment/purification, and digestion of proteins. This paper evaluates the role of different kinds of NMs in each step of protein sample preparation focusing on the type of established interaction between the protein and the nanomaterial, their sensitivity and selectivity, their adsorption capacity, and the advantages that they bring in relation to time, efficiency, or reusability.
{"title":"Nanomaterials in Protein Sample Preparation","authors":"E. González-García, M. Marina, M. C. García","doi":"10.1080/15422119.2019.1581216","DOIUrl":"https://doi.org/10.1080/15422119.2019.1581216","url":null,"abstract":"Protein sample preparation is the most critical step in protein analysis of complex samples and is constituted by tedious, time-consuming, and difficult-to-automate steps that usually involve the use of high volumes of solvents. In recent years, novel extraction or digestion nanomaterials (NMs) have been developed aiming to overcome these drawbacks. In this review, we have grouped the recent works related to the development of new NMs and their applications to the extraction, enrichment/purification, and digestion of proteins. This paper evaluates the role of different kinds of NMs in each step of protein sample preparation focusing on the type of established interaction between the protein and the nanomaterial, their sensitivity and selectivity, their adsorption capacity, and the advantages that they bring in relation to time, efficiency, or reusability.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"83 1","pages":"229 - 264"},"PeriodicalIF":0.0,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81711036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.1080/15422119.2020.1783311
M. E. González‐López, C. M. Laureano-Anzaldo, A. A. Pérez-Fonseca, M. Arellano, J. R. Robledo‐Ortíz
ABSTRACT Over the last decades, adsorption has emerged as a potential separation process for the removal of heavy metals that are extensively released in effluents from different industries. Among heavy metals, Cr(VI) is relevant due to its high toxicity, and its required concentration limit between 50 and 100 µg/L in water for human consumption. Several adsorbents, including silica, zeolites, clays, and carbon, are expensive for this application. This literature review proposed the use of novel adsorbents based on polysaccharides, mainly chitosan and cellulose, generalizing the effect of pH, equilibrium, kinetics, thermodynamics, and mechanism on the adsorption efficiency. It is shown that chitosan and cellulose exhibit a competitive Cr(VI) adsorption capacity reaching up to 625 and 358 mg/g, respectively. Also, a general review of sorbent reusability and continuous-flow adsorption is provided as they are critical for the highly extensive operation where maximum continuous-flow removals of 350 and 93 mg/g are reported for chitosan and cellulose. The use of polysaccharides as sorbents in batch and semi-continuous systems is an area of great interest and an opportunity to direct the efforts to provide state-of-the-art sorbents and technology for the removal of hexavalent chromium from polluted water streams.
{"title":"Chemically Modified Polysaccharides for Hexavalent Chromium Adsorption","authors":"M. E. González‐López, C. M. Laureano-Anzaldo, A. A. Pérez-Fonseca, M. Arellano, J. R. Robledo‐Ortíz","doi":"10.1080/15422119.2020.1783311","DOIUrl":"https://doi.org/10.1080/15422119.2020.1783311","url":null,"abstract":"ABSTRACT Over the last decades, adsorption has emerged as a potential separation process for the removal of heavy metals that are extensively released in effluents from different industries. Among heavy metals, Cr(VI) is relevant due to its high toxicity, and its required concentration limit between 50 and 100 µg/L in water for human consumption. Several adsorbents, including silica, zeolites, clays, and carbon, are expensive for this application. This literature review proposed the use of novel adsorbents based on polysaccharides, mainly chitosan and cellulose, generalizing the effect of pH, equilibrium, kinetics, thermodynamics, and mechanism on the adsorption efficiency. It is shown that chitosan and cellulose exhibit a competitive Cr(VI) adsorption capacity reaching up to 625 and 358 mg/g, respectively. Also, a general review of sorbent reusability and continuous-flow adsorption is provided as they are critical for the highly extensive operation where maximum continuous-flow removals of 350 and 93 mg/g are reported for chitosan and cellulose. The use of polysaccharides as sorbents in batch and semi-continuous systems is an area of great interest and an opportunity to direct the efforts to provide state-of-the-art sorbents and technology for the removal of hexavalent chromium from polluted water streams.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"28 1","pages":"333 - 362"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88786750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-22DOI: 10.1080/15422119.2020.1749852
Lucile Lecas, V. Dugas, C. Demesmay
ABSTRACT Affinity chromatography is an often overlooked chromatographic technique regarding receptor/ligand studies. Indeed, biologists have a tendency to focus on more recent biophysical techniques such as NMR or surface plasmon resonance methods, among others. However, in order to face challenges related to the use of membrane proteins in drug discovery, alternative and/or complementary methods are welcome. In this frame, chromatographic methods, through the affinity mode, bring new perspectives due to their relative simplicity and the great diversity of information that they can provide. Affinity chromatography methods rely on the immobilization of targets on the stationary phase and this step is crucial when dealing with membrane proteins. Different immobilization strategies with their own specificities (surface density, nonspecific interaction, complex surface chemistry of the taking or release step) were developed allowing to encompass a wide range of applications: from ligand-ranking (synthetic compounds of medium to high affinity) to fragment screening (small compounds of weak affinity), adsorption, distribution, metabolism, and excretion studies or identification of active components from natural extracts.
{"title":"Affinity Chromatography: A Powerful Tool in Drug Discovery for Investigating Ligand/membrane Protein Interactions","authors":"Lucile Lecas, V. Dugas, C. Demesmay","doi":"10.1080/15422119.2020.1749852","DOIUrl":"https://doi.org/10.1080/15422119.2020.1749852","url":null,"abstract":"ABSTRACT Affinity chromatography is an often overlooked chromatographic technique regarding receptor/ligand studies. Indeed, biologists have a tendency to focus on more recent biophysical techniques such as NMR or surface plasmon resonance methods, among others. However, in order to face challenges related to the use of membrane proteins in drug discovery, alternative and/or complementary methods are welcome. In this frame, chromatographic methods, through the affinity mode, bring new perspectives due to their relative simplicity and the great diversity of information that they can provide. Affinity chromatography methods rely on the immobilization of targets on the stationary phase and this step is crucial when dealing with membrane proteins. Different immobilization strategies with their own specificities (surface density, nonspecific interaction, complex surface chemistry of the taking or release step) were developed allowing to encompass a wide range of applications: from ligand-ranking (synthetic compounds of medium to high affinity) to fragment screening (small compounds of weak affinity), adsorption, distribution, metabolism, and excretion studies or identification of active components from natural extracts.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"1 1","pages":"315 - 332"},"PeriodicalIF":0.0,"publicationDate":"2020-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80486515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-14DOI: 10.1080/15422119.2020.1744649
Ajay Kumar, H. Joshi, Ashok Kumar
ABSTRACT Arsenic is a global concern as a groundwater contaminant due to its severe health consequences. Its removal employing nano adsorbents in both ex-situ and in-situ modes has gained attention among the scientific community from the past two and a half decades. Nanotechnology-based water treatment systems are a logical choice concerning resources and energy efficiency. The literature contains many cases in which several nanoadsorbents were used for arsenic removal. This review attempts to classify a variety of used nanoadsorbents according to their polymorphic structure and stability features, assessing the nature and modality of the bench-scale studies, identifying the removal mechanisms, and exploring further approaches for potential field-scale applications. A methodology to calculate the production cost of nanoadsorbents at a laboratory scale is also proposed.
{"title":"Remediation of Arsenic by Metal/ Metal Oxide Based Nanocomposites/ Nanohybrids: Contamination Scenario in Groundwater, Practical Challenges, and Future Perspectives","authors":"Ajay Kumar, H. Joshi, Ashok Kumar","doi":"10.1080/15422119.2020.1744649","DOIUrl":"https://doi.org/10.1080/15422119.2020.1744649","url":null,"abstract":"ABSTRACT Arsenic is a global concern as a groundwater contaminant due to its severe health consequences. Its removal employing nano adsorbents in both ex-situ and in-situ modes has gained attention among the scientific community from the past two and a half decades. Nanotechnology-based water treatment systems are a logical choice concerning resources and energy efficiency. The literature contains many cases in which several nanoadsorbents were used for arsenic removal. This review attempts to classify a variety of used nanoadsorbents according to their polymorphic structure and stability features, assessing the nature and modality of the bench-scale studies, identifying the removal mechanisms, and exploring further approaches for potential field-scale applications. A methodology to calculate the production cost of nanoadsorbents at a laboratory scale is also proposed.","PeriodicalId":21744,"journal":{"name":"Separation & Purification Reviews","volume":"27 1","pages":"283 - 314"},"PeriodicalIF":0.0,"publicationDate":"2020-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87647678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}