Pub Date : 2024-01-31DOI: 10.3390/membranes14020038
Francesco Chidichimo, Maria Rita Basile, Carmela Conidi, Giovanni De Filpo, Rosanna Morelli, Alfredo Cassano
A combination of straw filtration and nanofiltration was investigated for the first time as a sustainable approach aimed at valorizing olive mill wastewaters (OMWs) within a circular economy strategy. Ground straw filters with different granulometry (120, 250 and 500 μm) were tested in the first step to clarify the raw wastewater. The 500 μm filter offered the best performance due to a lower exposed surface of the filtering fibers and a shorter filtering time, allowing us to reduce about 70% of the chemical oxygen demand (COD) of the raw wastewater. Three different commercial membranes in a flat-sheet configuration with a molecular weight cut-off (MWCO) in the range 150-500 Da were tested to fractionate the clarified wastewater according to a dead-end configuration. Among the investigated membranes, a polymeric membrane of 500 Da (NFA-12A) exhibited the highest productivity in selected operating conditions (steady-state values of 11.4 L/m2 h at 20 bar and 24 ± 2 °C). In addition, flux decays for this membrane were lower than the other two tested membranes, indicating a lower propensity to fouling phenomena. Higher rejections towards total polyphenols and total antioxidant activity (TAA) (76.6% and 73.2%, respectively) were also observed for this membrane. Flavanols and hydroxycinnamic acids were retained by more than 99%. The combination of straw filtration and NF with the NFA-12A membrane allowed us to reduce the COD of raw OMWs up to 97.6%. The retentate fraction of this membrane exhibited a TAA of 18.9 ± 0.7 mM Trolox, supporting its propensity for the development of innovative formulations of interest in food and nutraceutical applications.
研究人员首次将秸秆过滤和纳滤结合起来,作为一种可持续的方法,旨在循环经济战略中实现橄榄油厂废水(OMWs)的价值化。第一步对不同粒度(120、250 和 500 μm)的研磨秸秆过滤器进行了测试,以澄清原始废水。500 μm 过滤器的性能最佳,因为其过滤纤维的暴露表面较低,过滤时间较短,可以减少原废水中约 70% 的化学需氧量 (COD)。我们测试了三种不同的平板结构商用膜,它们的截留分子量(MWCO)范围在 150-500 Da 之间,用于根据死端结构对澄清废水进行分馏。在所研究的膜中,分子量为 500 Da 的聚合物膜(NFA-12A)在选定的操作条件下表现出最高的生产率(在 20 bar 和 24 ± 2 °C 条件下,稳态值为 11.4 L/m2 h)。此外,这种膜的通量衰减低于其他两种测试膜,这表明其结垢现象的倾向性较低。还观察到这种膜对总多酚和总抗氧化活性(TAA)的剔除率较高(分别为 76.6% 和 73.2%)。黄烷醇和羟基肉桂酸的保留率超过 99%。将秸秆过滤和 NF 与 NFA-12A 膜结合使用,可将未加工 OMW 的化学需氧量降低 97.6%。该膜的回流部分显示出 18.9 ± 0.7 mM Trolox 的 TAA,支持其在食品和保健品应用中开发创新配方的倾向。
{"title":"A New Approach for Bioremediation of Olive Mill Wastewaters: Combination of Straw Filtration and Nanofiltration.","authors":"Francesco Chidichimo, Maria Rita Basile, Carmela Conidi, Giovanni De Filpo, Rosanna Morelli, Alfredo Cassano","doi":"10.3390/membranes14020038","DOIUrl":"10.3390/membranes14020038","url":null,"abstract":"<p><p>A combination of straw filtration and nanofiltration was investigated for the first time as a sustainable approach aimed at valorizing olive mill wastewaters (OMWs) within a circular economy strategy. Ground straw filters with different granulometry (120, 250 and 500 μm) were tested in the first step to clarify the raw wastewater. The 500 μm filter offered the best performance due to a lower exposed surface of the filtering fibers and a shorter filtering time, allowing us to reduce about 70% of the chemical oxygen demand (COD) of the raw wastewater. Three different commercial membranes in a flat-sheet configuration with a molecular weight cut-off (MWCO) in the range 150-500 Da were tested to fractionate the clarified wastewater according to a dead-end configuration. Among the investigated membranes, a polymeric membrane of 500 Da (NFA-12A) exhibited the highest productivity in selected operating conditions (steady-state values of 11.4 L/m<sup>2</sup> h at 20 bar and 24 ± 2 °C). In addition, flux decays for this membrane were lower than the other two tested membranes, indicating a lower propensity to fouling phenomena. Higher rejections towards total polyphenols and total antioxidant activity (TAA) (76.6% and 73.2%, respectively) were also observed for this membrane. Flavanols and hydroxycinnamic acids were retained by more than 99%. The combination of straw filtration and NF with the NFA-12A membrane allowed us to reduce the COD of raw OMWs up to 97.6%. The retentate fraction of this membrane exhibited a TAA of 18.9 ± 0.7 mM Trolox, supporting its propensity for the development of innovative formulations of interest in food and nutraceutical applications.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10890137/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139931854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of efficient, eco-friendly antimicrobial agents for air purification and disinfection addresses public health issues connected to preventing airborne pathogens. Herein, the antimicrobial activity of a nanoemulsion (control, 5%, 10%, and 15%) containing neem and lavender oils with polycaprolactone (PCL) was investigated against airborne bacteria, including Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Various parameters such as the physicochemical properties of the nanoemulsion, pH, droplet size, the polydispersity index (PDI), the minimum inhibitory concentration (MIC), the minimum bacterial concentration (MBC), and the color measurement of the emulsion have been evaluated and optimized. Our results showed that the antimicrobial activity of PCL combined with neem and lavender oil was found to be the highest MIC and MBC against all tested bacteria. The droplet sizes for lavender oil are 21.86-115.15 nm, the droplet sizes for neem oil are 23.92-119.15 nm, and their combination is 25.97-50.22 nm. The range of pH and viscosity of nanoemulsions of various concentrations was found to be 5.8 to 6.6 pH and 0.372 to 2.101 cP. This study highlights the potential of nanotechnology in harnessing the antimicrobial properties of natural essential oils, paving the way for innovative and sustainable solutions in the fight against bacterial contamination.
{"title":"Antimicrobial Activity of Polycaprolactone Nanofiber Coated with Lavender and Neem Oil Nanoemulsions against Airborne Bacteria.","authors":"Md Mahfuzur Rahman, Hari Kotturi, Sadegh Nikfarjam, Kanika Bhargava, Nagib Ahsan, Morshed Khandaker","doi":"10.3390/membranes14020036","DOIUrl":"10.3390/membranes14020036","url":null,"abstract":"<p><p>The development of efficient, eco-friendly antimicrobial agents for air purification and disinfection addresses public health issues connected to preventing airborne pathogens. Herein, the antimicrobial activity of a nanoemulsion (control, 5%, 10%, and 15%) containing neem and lavender oils with polycaprolactone (PCL) was investigated against airborne bacteria, including <i>Escherichia coli</i>, <i>Bacillus subtilis</i>, and <i>Staphylococcus aureus</i>. Various parameters such as the physicochemical properties of the nanoemulsion, pH, droplet size, the polydispersity index (PDI), the minimum inhibitory concentration (MIC), the minimum bacterial concentration (MBC), and the color measurement of the emulsion have been evaluated and optimized. Our results showed that the antimicrobial activity of PCL combined with neem and lavender oil was found to be the highest MIC and MBC against all tested bacteria. The droplet sizes for lavender oil are 21.86-115.15 nm, the droplet sizes for neem oil are 23.92-119.15 nm, and their combination is 25.97-50.22 nm. The range of pH and viscosity of nanoemulsions of various concentrations was found to be 5.8 to 6.6 pH and 0.372 to 2.101 cP. This study highlights the potential of nanotechnology in harnessing the antimicrobial properties of natural essential oils, paving the way for innovative and sustainable solutions in the fight against bacterial contamination.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10890609/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139931855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-29DOI: 10.3390/membranes14020037
Alisher M Kariev, Michael E Green
Ion channels are ubiquitous throughout all forms of life. Potassium channels are even found in viruses. Every cell must communicate with its surroundings, so all cells have them, and excitable cells, in particular, especially nerve cells, depend on the behavior of these channels. Every channel must be open at the appropriate time, and only then, so that each channel opens in response to the stimulus that tells that channel to open. One set of channels, including those in nerve cells, responds to voltage. There is a standard model for the gating of these channels that has a section of the protein moving in response to the voltage. However, there is evidence that protons are moving, rather than protein. Water is critical as part of the gating process, although it is hard to see how this works in the standard model. Here, we review the extensive evidence of the importance of the role of water and protons in gating these channels. Our principal example, but by no means the only example, will be the Kv1.2 channel. Evidence comes from the effects of D2O, from mutations in the voltage sensing domain, as well as in the linker between that domain and the gate, and at the gate itself. There is additional evidence from computations, especially quantum calculations. Structural evidence comes from X-ray studies. The hydration of ions is critical in the transfer of ions in constricted spaces, such as the gate region and the pore of a channel; we will see how the structure of the hydrated ion fits with the structure of the channel. In addition, there is macroscopic evidence from osmotic experiments and streaming current measurements. The combined evidence is discussed in the context of a model that emphasizes the role of protons and water in gating these channels.
离子通道在所有生命形式中无处不在。病毒中甚至也有钾离子通道。每个细胞都必须与周围环境进行交流,因此所有细胞都有离子通道,尤其是兴奋性细胞,特别是神经细胞,都依赖于这些通道的行为。每条通道都必须在适当的时候打开,而且只能在适当的时候打开,因此每条通道的打开都是对告诉该通道打开的刺激的反应。其中一组通道,包括神经细胞中的通道,会对电压做出反应。这些通道的门控有一个标准模型,即蛋白质的一部分随电压而移动。然而,有证据表明,移动的是质子,而不是蛋白质。水是门控过程的关键,尽管在标准模型中很难看到这一点。在此,我们回顾了水和质子在这些通道门控中的重要作用的大量证据。我们将以 Kv1.2 通道为例,但这绝不是唯一的例子。证据来自 D2O 的影响、电压感应结构域的突变、该结构域与栅极之间的连接体以及栅极本身。还有一些证据来自计算,特别是量子计算。结构证据来自 X 射线研究。离子的水合作用对于离子在狭小空间(如通道的栅极区域和孔隙)中的转移至关重要;我们将看到水合离子的结构如何与通道的结构相匹配。此外,渗透实验和流式电流测量也提供了宏观证据。我们将在强调质子和水在这些通道门控中的作用的模型中讨论综合证据。
{"title":"Water, Protons, and the Gating of Voltage-Gated Potassium Channels.","authors":"Alisher M Kariev, Michael E Green","doi":"10.3390/membranes14020037","DOIUrl":"10.3390/membranes14020037","url":null,"abstract":"<p><p>Ion channels are ubiquitous throughout all forms of life. Potassium channels are even found in viruses. Every cell must communicate with its surroundings, so all cells have them, and excitable cells, in particular, especially nerve cells, depend on the behavior of these channels. Every channel must be open at the appropriate time, and only then, so that each channel opens in response to the stimulus that tells that channel to open. One set of channels, including those in nerve cells, responds to voltage. There is a standard model for the gating of these channels that has a section of the protein moving in response to the voltage. However, there is evidence that protons are moving, rather than protein. Water is critical as part of the gating process, although it is hard to see how this works in the standard model. Here, we review the extensive evidence of the importance of the role of water and protons in gating these channels. Our principal example, but by no means the only example, will be the K<sub>v</sub>1.2 channel. Evidence comes from the effects of D<sub>2</sub>O, from mutations in the voltage sensing domain, as well as in the linker between that domain and the gate, and at the gate itself. There is additional evidence from computations, especially quantum calculations. Structural evidence comes from X-ray studies. The hydration of ions is critical in the transfer of ions in constricted spaces, such as the gate region and the pore of a channel; we will see how the structure of the hydrated ion fits with the structure of the channel. In addition, there is macroscopic evidence from osmotic experiments and streaming current measurements. The combined evidence is discussed in the context of a model that emphasizes the role of protons and water in gating these channels.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10890431/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139931858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-27DOI: 10.3390/membranes14020034
Ralph A Bauer, Minghui Qiu, Melissa C Schillo-Armstrong, Matthew T Snider, Zi Yang, Yi Zhou, Hendrik Verweij
Thin, supported inorganic mesoporous membranes are used for the removal of salts, small molecules (PFAS, dyes, and polyanions) and particulate species (oil droplets) from aqueous sources with high flux and selectivity. Nanofiltration membranes can reject simple salts with 80-100% selectivity through a space charge mechanism. Rejection by size selectivity can be near 100% since the membranes can have a very narrow size distribution. Mesoporous membranes have received particular interest due to their (potential) stability under operational conditions and during defouling operations. More recently, membranes with extreme stability became interesting with the advent of in situ fouling mitigation by means of ultrasound emitted from within the membrane structure. For this reason, we explored the stability of available and new membranes with accelerated lifetime tests in aqueous solutions at various temperatures and pH values. Of the available ceria, titania, and magnetite membranes, none were actually stable under all test conditions. In earlier work, it was established that mesoporous alumina membranes have very poor stability. A new nanofiltration membrane was made of cubic zirconia membranes that exhibited near-perfect stability. A new ultrafiltration membrane was made of amorphous silica that was fully stable in ultrapure water at 80 °C. This work provides details of membrane synthesis, stability characterization and data and their interpretation.
薄型支撑无机介孔膜可用于去除水源中的盐类、小分子(全氟辛烷磺酸、染料和聚阴离子)和颗粒物(油滴),并具有高通量和高选择性。纳滤膜可通过空间电荷机制以 80-100% 的选择性去除简单的盐类。由于纳滤膜的尺寸分布非常窄,因此其尺寸选择性可接近 100%。介孔膜因其在操作条件下和除污操作期间的(潜在)稳定性而受到特别关注。最近,随着通过膜结构内部发射的超声波进行原位污垢缓解的出现,具有极高稳定性的膜变得非常有趣。因此,我们通过在不同温度和 pH 值的水溶液中进行加速寿命测试,探索了现有膜和新型膜的稳定性。在现有的铈膜、二氧化钛膜和磁铁矿膜中,没有一种能在所有测试条件下保持稳定。在早期的工作中,已经确定介孔氧化铝膜的稳定性非常差。由立方氧化锆膜制成的新型纳滤膜表现出近乎完美的稳定性。由无定形二氧化硅制成的新型超滤膜在 80 °C 的超纯水中完全稳定。这项工作提供了膜合成、稳定性表征和数据及其解释的详细信息。
{"title":"Ultra-Stable Inorganic Mesoporous Membranes for Water Purification.","authors":"Ralph A Bauer, Minghui Qiu, Melissa C Schillo-Armstrong, Matthew T Snider, Zi Yang, Yi Zhou, Hendrik Verweij","doi":"10.3390/membranes14020034","DOIUrl":"10.3390/membranes14020034","url":null,"abstract":"<p><p>Thin, supported inorganic mesoporous membranes are used for the removal of salts, small molecules (PFAS, dyes, and polyanions) and particulate species (oil droplets) from aqueous sources with high flux and selectivity. Nanofiltration membranes can reject simple salts with 80-100% selectivity through a space charge mechanism. Rejection by size selectivity can be near 100% since the membranes can have a very narrow size distribution. Mesoporous membranes have received particular interest due to their (potential) stability under operational conditions and during defouling operations. More recently, membranes with extreme stability became interesting with the advent of in situ fouling mitigation by means of ultrasound emitted from within the membrane structure. For this reason, we explored the stability of available and new membranes with accelerated lifetime tests in aqueous solutions at various temperatures and pH values. Of the available ceria, titania, and magnetite membranes, none were actually stable under all test conditions. In earlier work, it was established that mesoporous alumina membranes have very poor stability. A new nanofiltration membrane was made of cubic zirconia membranes that exhibited near-perfect stability. A new ultrafiltration membrane was made of amorphous silica that was fully stable in ultrapure water at 80 °C. This work provides details of membrane synthesis, stability characterization and data and their interpretation.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10890243/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139931857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Membrane fouling presents a significant challenge in the treatment of wastewater. Several detection methods have been used to interpret membrane fouling processes. Compared with other analysis and detection methods, atomic force microscopy (AFM) is widely used because of its advantages in liquid-phase in situ 3D imaging, ability to measure interactive forces, and mild testing conditions. Although AFM has been widely used in the study of membrane fouling, the current literature has not fully explored its potential. This review aims to uncover and provide a new perspective on the application of AFM technology in future studies on membrane fouling. Initially, a rigorous review was conducted on the morphology, roughness, and interaction forces of AFM in situ characterization of membranes and foulants. Then, the application of AFM in the process of changing membrane fouling factors was reviewed based on its in situ measurement capability, and it was found that changes in ionic conditions, pH, voltage, and even time can cause changes in membrane fouling morphology and forces. Existing membrane fouling models are then discussed, and the role of AFM in predicting and testing these models is presented. Finally, the potential of the improved AFM techniques to be applied in the field of membrane fouling has been underestimated. In this paper, we have fully elucidated the potentials of the improved AFM techniques to be applied in the process of membrane fouling, and we have presented the current challenges and the directions for the future development in an attempt to provide new insights into this field.
{"title":"Employing Atomic Force Microscopy (AFM) for Microscale Investigation of Interfaces and Interactions in Membrane Fouling Processes: New Perspectives and Prospects.","authors":"Mohan Wei, Yaozhong Zhang, Yifan Wang, Xiaoping Liu, Xiaoliang Li, Xing Zheng","doi":"10.3390/membranes14020035","DOIUrl":"10.3390/membranes14020035","url":null,"abstract":"<p><p>Membrane fouling presents a significant challenge in the treatment of wastewater. Several detection methods have been used to interpret membrane fouling processes. Compared with other analysis and detection methods, atomic force microscopy (AFM) is widely used because of its advantages in liquid-phase in situ 3D imaging, ability to measure interactive forces, and mild testing conditions. Although AFM has been widely used in the study of membrane fouling, the current literature has not fully explored its potential. This review aims to uncover and provide a new perspective on the application of AFM technology in future studies on membrane fouling. Initially, a rigorous review was conducted on the morphology, roughness, and interaction forces of AFM in situ characterization of membranes and foulants. Then, the application of AFM in the process of changing membrane fouling factors was reviewed based on its in situ measurement capability, and it was found that changes in ionic conditions, pH, voltage, and even time can cause changes in membrane fouling morphology and forces. Existing membrane fouling models are then discussed, and the role of AFM in predicting and testing these models is presented. Finally, the potential of the improved AFM techniques to be applied in the field of membrane fouling has been underestimated. In this paper, we have fully elucidated the potentials of the improved AFM techniques to be applied in the process of membrane fouling, and we have presented the current challenges and the directions for the future development in an attempt to provide new insights into this field.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 2","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10890076/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139931856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-21DOI: 10.3390/membranes14010026
Eric Suryawirawan, Anja E M Janssen, Remko M Boom, Albert van der Padt
The classic application of ultrafiltration (UF) is for the complete retention of proteins, and in that situation, the transport behavior is well established. More open membranes with fractional retention are used when separating different proteins. However, protein transport has not been well documented yet in the literature. The bovine serum albumin (∼69 kDa) observed rejection ranges from 0.65 to 1 using a 300 kDa molecular weight cut-off membrane at different pH, ionic strength, and pressure. We demonstrated that, especially with open UF, the transport of proteins through the membrane is dominated by advection, with insignificant diffusion effects (p value > 0.05). We showed that with open UF, retention is not only caused by size exclusion but also to a large extent by electrostatic interactions and oligomerization of the proteins. Mass transfer in the polarization layer was relatively independent of the pH and ionic strength. It was underestimated by common Sherwood relations due to a relatively large contribution of the reduction in the flow turbulence near the membrane by the removal of fluid through the membrane. We propose a model that allows relatively quick characterization of the rejection of proteins without prior knowledge of the pore sizes and charges based on just a limited set of experiments. Therefore, protein rejection with the open UF system can be targeted by tuning the processing conditions, which might be useful for designing protein fractionation processes.
{"title":"Bovine Serum Albumin Rejection by an Open Ultrafiltration Membrane: Characterization and Modeling.","authors":"Eric Suryawirawan, Anja E M Janssen, Remko M Boom, Albert van der Padt","doi":"10.3390/membranes14010026","DOIUrl":"10.3390/membranes14010026","url":null,"abstract":"<p><p>The classic application of ultrafiltration (UF) is for the complete retention of proteins, and in that situation, the transport behavior is well established. More open membranes with fractional retention are used when separating different proteins. However, protein transport has not been well documented yet in the literature. The bovine serum albumin (∼69 kDa) observed rejection ranges from 0.65 to 1 using a 300 kDa molecular weight cut-off membrane at different pH, ionic strength, and pressure. We demonstrated that, especially with open UF, the transport of proteins through the membrane is dominated by advection, with insignificant diffusion effects (<i>p</i> value > 0.05). We showed that with open UF, retention is not only caused by size exclusion but also to a large extent by electrostatic interactions and oligomerization of the proteins. Mass transfer in the polarization layer was relatively independent of the pH and ionic strength. It was underestimated by common Sherwood relations due to a relatively large contribution of the reduction in the flow turbulence near the membrane by the removal of fluid through the membrane. We propose a model that allows relatively quick characterization of the rejection of proteins without prior knowledge of the pore sizes and charges based on just a limited set of experiments. Therefore, protein rejection with the open UF system can be targeted by tuning the processing conditions, which might be useful for designing protein fractionation processes.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11154442/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139564371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.3390/membranes14010025
Heng Zhang, Haizhen Xian
Membrane distillation (MD) is an attractive separation process that can work with heat sources with low temperature differences and is less sensitive to concentration polarization and membrane fouling than other pressure-driven membrane separation processes, thus allowing it to use low-grade thermal energy, which is helpful to decrease the consumption of energy, treat concentrated solutions, and improve water recovery rate. This paper provides a review of the integration of MD with waste heat and renewable energy, such as solar radiation, salt-gradient solar ponds, and geothermal energy, for desalination. In addition, MD hybrids with pressure-retarded osmosis (PRO), multi-effect distillation (MED), reverse osmosis (RO), crystallization, forward osmosis (FO), and bioreactors to dispose of concentrated solutions are also comprehensively summarized. A critical analysis of the hybrid MD systems will be helpful for the research and development of MD technology and will promote its application. Eventually, a possible research direction for MD is suggested.
{"title":"Review of Hybrid Membrane Distillation Systems.","authors":"Heng Zhang, Haizhen Xian","doi":"10.3390/membranes14010025","DOIUrl":"10.3390/membranes14010025","url":null,"abstract":"<p><p>Membrane distillation (MD) is an attractive separation process that can work with heat sources with low temperature differences and is less sensitive to concentration polarization and membrane fouling than other pressure-driven membrane separation processes, thus allowing it to use low-grade thermal energy, which is helpful to decrease the consumption of energy, treat concentrated solutions, and improve water recovery rate. This paper provides a review of the integration of MD with waste heat and renewable energy, such as solar radiation, salt-gradient solar ponds, and geothermal energy, for desalination. In addition, MD hybrids with pressure-retarded osmosis (PRO), multi-effect distillation (MED), reverse osmosis (RO), crystallization, forward osmosis (FO), and bioreactors to dispose of concentrated solutions are also comprehensively summarized. A critical analysis of the hybrid MD systems will be helpful for the research and development of MD technology and will promote its application. Eventually, a possible research direction for MD is suggested.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10820896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139512823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-17DOI: 10.3390/membranes14010023
Stef Depuydt, Bart Van der Bruggen
Cation exchange membranes (CEMs) play a significant role in the transition to a more sustainable/green society. They are important components for applications such as water electrolysis, artificial photosynthesis, electrodialysis and fuel cells. Their synthesis, however, is far from being sustainable, affecting safety, health and the environment. This review discusses and evaluates the possibilities of synthesizing CEMs that are more sustainable and green. First, the concepts of green and sustainable chemistry are discussed. Subsequently, this review discusses the fabrication of conventional perfluorinated CEMs and how they violate the green/sustainability principles, eventually leading to environmental and health incidents. Furthermore, the synthesis of green CEMs is presented by dividing the synthesis into three parts: sulfonation, material selection and solvent selection. Innovations in using gaseous SO3 or gas-liquid interfacial plasma technology can make the sulfonation process more sustainable. Regarding the selection of polymers, chitosan, cellulose, polylactic acid, alginate, carrageenan and cellulose are promising alternatives to fossil fuel-based polymers. Finally, water is the most sustainable solvent and many biopolymers are soluble in it. For other polymers, there are a limited number of studies using green solvents. Promising solvents are found back in other membrane, such as dimethyl sulfoxide, Cyrene™, Rhodiasolv® PolarClean, TamiSolve NxG and γ-valerolactone.
阳离子交换膜(CEM)在向更可持续/绿色社会过渡的过程中发挥着重要作用。它们是水电解、人工光合作用、电渗析和燃料电池等应用的重要组成部分。然而,它们的合成远非可持续,会影响安全、健康和环境。本综述将讨论和评估合成更具可持续性和绿色的 CEMs 的可能性。首先,讨论绿色和可持续化学的概念。随后,本综述讨论了传统全氟 CEM 的制造及其如何违反绿色/可持续原则,最终导致环境和健康事故。此外,还介绍了绿色 CEM 的合成,将合成分为三个部分:磺化、材料选择和溶剂选择。使用气态 SO3 或气液界面等离子体技术的创新可使磺化过程更具可持续性。在聚合物的选择方面,壳聚糖、纤维素、聚乳酸、海藻酸、卡拉胶和纤维素是化石燃料聚合物的有前途的替代品。最后,水是最可持续的溶剂,许多生物聚合物都能溶于水。对于其他聚合物,使用绿色溶剂的研究数量有限。在其他膜中也发现了有前景的溶剂,如二甲基亚砜、Cyrene™、Rhodiasolv® PolarClean、TamiSolve NxG 和 γ-缬内酯。
{"title":"Green Synthesis of Cation Exchange Membranes: A Review.","authors":"Stef Depuydt, Bart Van der Bruggen","doi":"10.3390/membranes14010023","DOIUrl":"10.3390/membranes14010023","url":null,"abstract":"<p><p>Cation exchange membranes (CEMs) play a significant role in the transition to a more sustainable/green society. They are important components for applications such as water electrolysis, artificial photosynthesis, electrodialysis and fuel cells. Their synthesis, however, is far from being sustainable, affecting safety, health and the environment. This review discusses and evaluates the possibilities of synthesizing CEMs that are more sustainable and green. First, the concepts of green and sustainable chemistry are discussed. Subsequently, this review discusses the fabrication of conventional perfluorinated CEMs and how they violate the green/sustainability principles, eventually leading to environmental and health incidents. Furthermore, the synthesis of green CEMs is presented by dividing the synthesis into three parts: sulfonation, material selection and solvent selection. Innovations in using gaseous SO3 or gas-liquid interfacial plasma technology can make the sulfonation process more sustainable. Regarding the selection of polymers, chitosan, cellulose, polylactic acid, alginate, carrageenan and cellulose are promising alternatives to fossil fuel-based polymers. Finally, water is the most sustainable solvent and many biopolymers are soluble in it. For other polymers, there are a limited number of studies using green solvents. Promising solvents are found back in other membrane, such as dimethyl sulfoxide, Cyrene™, Rhodiasolv<sup>®</sup> PolarClean, TamiSolve NxG and γ-valerolactone.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10819081/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139512705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-17DOI: 10.3390/membranes14010024
Ruirui Ma, Juan Li, Ping Zeng, Liang Duan, Jimin Dong, Yunxia Ma, Lingkong Yang
With the advancement in membrane technology, membrane separation technology has been found increasingly widespread applications in the pharmaceutical industry. It is utilized in drug separation and purification, wastewater treatment, and the recycling of wastewater resources. This study summarizes the application history of membrane technology in the pharmaceutical industry, presents practical engineering examples of its applications, analyzes the various types of membrane technologies employed in the pharmaceutical sector, and finally, highlights the application cases of renowned international and Chinese membrane technology companies in the pharmaceutical field.
{"title":"The Application of Membrane Separation Technology in the Pharmaceutical Industry.","authors":"Ruirui Ma, Juan Li, Ping Zeng, Liang Duan, Jimin Dong, Yunxia Ma, Lingkong Yang","doi":"10.3390/membranes14010024","DOIUrl":"10.3390/membranes14010024","url":null,"abstract":"<p><p>With the advancement in membrane technology, membrane separation technology has been found increasingly widespread applications in the pharmaceutical industry. It is utilized in drug separation and purification, wastewater treatment, and the recycling of wastewater resources. This study summarizes the application history of membrane technology in the pharmaceutical industry, presents practical engineering examples of its applications, analyzes the various types of membrane technologies employed in the pharmaceutical sector, and finally, highlights the application cases of renowned international and Chinese membrane technology companies in the pharmaceutical field.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10818260/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139512826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-15DOI: 10.3390/membranes14010022
Asif Jan, Mingliang Chen, Michiel Nijboer, Mieke W J Luiten-Olieman, Luuk C Rietveld, Sebastiaan G J Heijman
Sodium hypochlorite (NaClO) is widely used for the chemical cleaning of fouled ultrafiltration (UF) membranes. Various studies performed on polymeric membranes demonstrate that long-term (>100 h) exposure to NaClO deteriorates the physicochemical properties of the membranes, leading to reduced performance and service life. However, the effect of NaClO cleaning on ceramic membranes, particularly the number of cleaning cycles they can undergo to alleviate irreversible fouling, remains poorly understood. Silicon carbide (SiC) membranes have garnered widespread attention for water and wastewater treatment, but their chemical stability in NaClO has not been studied. Low-pressure chemical vapor deposition (LP-CVD) provides a simple and economical route to prepare/modify ceramic membranes. As such, LP-CVD facilitates the preparation of SiC membranes: (a) in a single step; and (b) at much lower temperatures (700-900 °C) in comparison with sol-gel methods (ca. 2000 °C). In this work, SiC ultrafiltration (UF) membranes were prepared via LP-CVD at two different deposition temperatures and pressures. Subsequently, their chemical stability in NaClO was investigated over 200 h of aging. Afterward, the properties and performance of as-prepared SiC UF membranes were evaluated before and after aging to determine the optimal deposition conditions. Our results indicate that the SiC UF membrane prepared via LP-CVD at 860 °C and 100 mTorr exhibited excellent resistance to NaClO aging, while the membrane prepared at 750 °C and 600 mTorr significantly deteriorated. These findings not only highlight a novel preparation route for SiC membranes in a single step via LP-CVD, but also provide new insights about the careful selection of LP-CVD conditions for SiC membranes to ensure their long-term performance and robustness under harsh chemical cleaning conditions.
次氯酸钠(NaClO)被广泛用于污垢超滤膜的化学清洗。对聚合物膜进行的各种研究表明,长期(大于 100 小时)接触 NaClO 会恶化膜的物理化学特性,导致性能和使用寿命降低。然而,NaClO 清洁对陶瓷膜的影响,特别是陶瓷膜为减轻不可逆污垢而可进行的清洁循环次数,仍然鲜为人知。碳化硅(SiC)膜在水和废水处理方面受到广泛关注,但其在 NaClO 中的化学稳定性尚未得到研究。低压化学气相沉积(LP-CVD)为制备/改性陶瓷膜提供了一条简单而经济的途径。因此,低压化学气相沉积法有利于制备碳化硅膜:(a) 一步到位;(b) 与溶胶凝胶法(约 2000 ℃)相比,温度更低(700-900 ℃)。在这项工作中,通过 LP-CVD 在两种不同的沉积温度和压力下制备了 SiC 超滤膜。随后,对其在 NaClO 中 200 小时的老化过程中的化学稳定性进行了研究。随后,对老化前后制备的碳化硅超滤膜的特性和性能进行了评估,以确定最佳沉积条件。我们的结果表明,在 860 °C 和 100 mTorr 下通过 LP-CVD 制备的 SiC 超滤膜对 NaClO 老化具有极佳的耐受性,而在 750 °C 和 600 mTorr 下制备的膜则明显变差。这些发现不仅强调了通过 LP-CVD 一步法制备 SiC 膜的新路线,而且为仔细选择 SiC 膜的 LP-CVD 条件以确保其在苛刻的化学清洗条件下的长期性能和稳健性提供了新的见解。
{"title":"Effect of Long-Term Sodium Hypochlorite Cleaning on Silicon Carbide Ultrafiltration Membranes Prepared via Low-Pressure Chemical Vapor Deposition.","authors":"Asif Jan, Mingliang Chen, Michiel Nijboer, Mieke W J Luiten-Olieman, Luuk C Rietveld, Sebastiaan G J Heijman","doi":"10.3390/membranes14010022","DOIUrl":"10.3390/membranes14010022","url":null,"abstract":"<p><p>Sodium hypochlorite (NaClO) is widely used for the chemical cleaning of fouled ultrafiltration (UF) membranes. Various studies performed on polymeric membranes demonstrate that long-term (>100 h) exposure to NaClO deteriorates the physicochemical properties of the membranes, leading to reduced performance and service life. However, the effect of NaClO cleaning on ceramic membranes, particularly the number of cleaning cycles they can undergo to alleviate irreversible fouling, remains poorly understood. Silicon carbide (SiC) membranes have garnered widespread attention for water and wastewater treatment, but their chemical stability in NaClO has not been studied. Low-pressure chemical vapor deposition (LP-CVD) provides a simple and economical route to prepare/modify ceramic membranes. As such, LP-CVD facilitates the preparation of SiC membranes: (a) in a single step; and (b) at much lower temperatures (700-900 °C) in comparison with sol-gel methods (ca. 2000 °C). In this work, SiC ultrafiltration (UF) membranes were prepared via LP-CVD at two different deposition temperatures and pressures. Subsequently, their chemical stability in NaClO was investigated over 200 h of aging. Afterward, the properties and performance of as-prepared SiC UF membranes were evaluated before and after aging to determine the optimal deposition conditions. Our results indicate that the SiC UF membrane prepared via LP-CVD at 860 °C and 100 mTorr exhibited excellent resistance to NaClO aging, while the membrane prepared at 750 °C and 600 mTorr significantly deteriorated. These findings not only highlight a novel preparation route for SiC membranes in a single step via LP-CVD, but also provide new insights about the careful selection of LP-CVD conditions for SiC membranes to ensure their long-term performance and robustness under harsh chemical cleaning conditions.</p>","PeriodicalId":18410,"journal":{"name":"Membranes","volume":"14 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10820315/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139512703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}