Pub Date : 2024-09-24DOI: 10.1016/j.seppur.2024.129800
The adsorption of carbon dioxide on the catalyst surface is often neglected, and the improvement of adsorption activation capacity is important to realize the efficient conversion of carbon dioxide. In this paper, a novel layered double hydroxide Co-MgAl-LDH (CML) with frustrated Lewis pairs (FLPs) was successfully prepared by one-step hydrothermal doping of transition metal Co, which Co2+ and the oxygen vacancies brought about by the doping (Co2+-Vo) are the Lewis acid site, and adjacent hydroxyls are the Lewis base site, and In-situ experiments and Density Functional Theory (DFT) demonstrated that the FLPs effectively enhanced the CO2 adsorption activation capacity of CML. The present work provides a new idea for modifying Layered double hydroxides (LDH) to construct FLPs, and also offers new hope for constructing high-performance LDH-based CO2 reduction photocatalysts.
二氧化碳在催化剂表面的吸附作用往往被忽视，而提高吸附活化能力对于实现二氧化碳的高效转化具有重要意义。本文通过一步水热法掺杂过渡金属 Co 成功制备了具有受挫路易斯对（FLPs）的新型层状双氢氧化物 Co-MgAl-LDH（CML），其中 Co2+ 和掺杂带来的氧空位（Co2+-Vo）为路易斯酸位，相邻羟基为路易斯碱位，原位实验和密度泛函理论（DFT）证明 FLPs 有效提高了 CML 的二氧化碳吸附活化能力。本研究为改性层状双氢氧化物（LDH）构建FLPs提供了新思路，也为构建基于LDH的高性能CO2还原光催化剂带来了新希望。
{"title":"Restructuring surface frustrated Lewis pairs of MgAl-LDH through isomorphous Co doping for accelerating photocatalytic CO2 reduction","authors":"","doi":"10.1016/j.seppur.2024.129800","DOIUrl":"10.1016/j.seppur.2024.129800","url":null,"abstract":"<div><div>The adsorption of carbon dioxide on the catalyst surface is often neglected, and the improvement of adsorption activation capacity is important to realize the efficient conversion of carbon dioxide. In this paper, a novel layered double hydroxide Co-MgAl-LDH (CML) with frustrated Lewis pairs (FLPs) was successfully prepared by one-step hydrothermal doping of transition metal Co, which Co<sup>2+</sup> and the oxygen vacancies brought about by the doping (Co<sup>2+</sup>-Vo) are the Lewis acid site, and adjacent hydroxyls are the Lewis base site, and In-situ experiments and Density Functional Theory (DFT) demonstrated that the FLPs effectively enhanced the CO<sub>2</sub> adsorption activation capacity of CML. The present work provides a new idea for modifying Layered double hydroxides (LDH) to construct FLPs, and also offers new hope for constructing high-performance LDH-based CO<sub>2</sub> reduction photocatalysts.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129770
Germanium is a strategic metal that is challenging to enrich and purify without any side effects, especially stability and selectivity. Here the role of carbonyl acid in selective separation of germanium from complex industrial liquids was highlighted. Integrating theoretical and experimental analyses, carbonyl acids exhibit strong binding ability and high selectivity to germanium was demonstrated. The first set of carbonyl acid extractant (CAE) for germanium extraction was successfully synthesized with a solubility of less than 50 mg/L at pH = 0. The process analysis exhibits the extraction rate of germanium in a single stage by CAEs exceeds 99.9 %, while the separation factor surpasses 103, far beyond 101 of hydroxamic acids. Furthermore, the stripping rate for germanium in a single stage exceeds 83.0 %, with germanium accounting for over 99.9 % of the total metal content in the stripping solution. The CAE extraction process is straightforward and characterized by high germanium separation efficiency. The development of CAE not only realises the stable, green, low-carbon, and high-efficiency purification of germanium, but also the universality and inspiration of CAE make it highly significant and valuable in both theoretical research and practical applications.
{"title":"An improvement for enrichment and purification of germanium using carbonyl acid extractants","authors":"","doi":"10.1016/j.seppur.2024.129770","DOIUrl":"10.1016/j.seppur.2024.129770","url":null,"abstract":"<div><div>Germanium is a strategic metal that is challenging to enrich and purify without any side effects, especially stability and selectivity. Here the role of carbonyl acid in selective separation of germanium from complex industrial liquids was highlighted. Integrating theoretical and experimental analyses, carbonyl acids exhibit strong binding ability and high selectivity to germanium was demonstrated. The first set of carbonyl acid extractant (CAE) for germanium extraction was successfully synthesized with a solubility of less than 50 mg/L at pH = 0. The process analysis exhibits the extraction rate of germanium in a single stage by CAEs exceeds 99.9 %, while the separation factor surpasses 10<sup>3</sup>, far beyond 10<sup>1</sup> of hydroxamic acids. Furthermore, the stripping rate for germanium in a single stage exceeds 83.0 %, with germanium accounting for over 99.9 % of the total metal content in the stripping solution. The CAE extraction process is straightforward and characterized by high germanium separation efficiency. The development of CAE not only realises the stable, green, low-carbon, and high-efficiency purification of germanium, but also the universality and inspiration of CAE make it highly significant and valuable in both theoretical research and practical applications.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129849
The low selectivity of traditional organic solvents and the limited mass transfer efficiency caused by the high viscosity of ionic liquids (ILs) pose challenges in separating of dimethyl carbonate (DMC)/methanol/water mixtures. Therefore, a novel mixed solvent is proposed with a mass ratio of methyl salicylate to 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide of 6:4. The synergistic effects of thermodynamic, kinetic, and economic performance using the mixed solvent are investigated. Comparisons of overall efficiency and total annual cost (TAC) for four process configurations using direct and indirect extractive distillation sequences to produce industrial and battery-grade DMC products are conducted. The results indicate that direct extractive distillation outperforms the indirect sequence, reducing TAC by 6.1–14.3 % for producing industrial-grade DMC and 6.6–15.8 % for battery-grade DMC. Additionally, using mixed solvents in direct extractive distillation is more effective than using pure solvents, enhancing mass transfer coefficients by 2.8–20.9 % for industrial-grade DMC and 1.8–17.8 % for battery-grade DMC. This approach also reduces TAC by 3.2–3.6 % for industrial-grade DMC and 4.7–5.7 % for battery-grade DMC.
{"title":"Thermo-kinetic synergy in separating dimethyl carbonate/methanol/water mixtures using ionic liquids-based mixed solvents","authors":"","doi":"10.1016/j.seppur.2024.129849","DOIUrl":"10.1016/j.seppur.2024.129849","url":null,"abstract":"<div><div>The low selectivity of traditional organic solvents and the limited mass transfer efficiency caused by the high viscosity of ionic liquids (ILs) pose challenges in separating of dimethyl carbonate (DMC)/methanol/water mixtures. Therefore, a novel mixed solvent is proposed with a mass ratio of methyl salicylate to 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide of 6:4. The synergistic effects of thermodynamic, kinetic, and economic performance using the mixed solvent are investigated. Comparisons of overall efficiency and total annual cost (TAC) for four process configurations using direct and indirect extractive distillation sequences to produce industrial and battery-grade DMC products are conducted. The results indicate that direct extractive distillation outperforms the indirect sequence, reducing TAC by 6.1–14.3 % for producing industrial-grade DMC and 6.6–15.8 % for battery-grade DMC. Additionally, using mixed solvents in direct extractive distillation is more effective than using pure solvents, enhancing mass transfer coefficients by 2.8–20.9 % for industrial-grade DMC and 1.8–17.8 % for battery-grade DMC. This approach also reduces TAC by 3.2–3.6 % for industrial-grade DMC and 4.7–5.7 % for battery-grade DMC.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129855
The nonaqueous biphasic absorbent was a great choice to overcome the difficulties of high energy consumption and lower desorption efficiency in carbon dioxide (CO2) regeneration processes of traditional chemical absorbents. In this work, a poly-ether solvent poly(oxymethylene) dimethyl ethers (PODE3-5) was introduced as phase separation agent in the anhydrous solution of primary amine 2-(2-aminoethoxy) ethanol (DGA) and dimethyl sulfoxide (DMSO). The optimal DGA/PODE3-5/DMSO biphasic absorbent could have a CO2 capacity of 0.60 mol/mol, with 94.2 % of the charged CO2 concentrated in the lower phase that representing only 48.1 % of the total liquid volume. And the DGA/PODE3-5/DMSO biphasic absorbent had a high CO2 desorption efficiency of up to 90 % in 30 min and a stable cycling capacity of 0.54 mol/mol. Further, the products and reaction mechanism of CO2 absorption process were analyzed based on the results of 13C NMR. The phase separation was triggered by the polarity enhancement of products and the affinity difference to products between PODE3-5 and DMSO. Particularly, the regeneration energy requirement of the DGA/PODE3-5/DMSO biphasic absorbent was 1.90 GJ ton-1 CO2, which is 51.1 % less than 30 wt% MEA-H2O solution.
{"title":"Efficient desorption and energy-saving carbon capture using a nonaqueous primary alkanolamine-based biphasic absorbent","authors":"","doi":"10.1016/j.seppur.2024.129855","DOIUrl":"10.1016/j.seppur.2024.129855","url":null,"abstract":"<div><div>The nonaqueous biphasic absorbent was a great choice to overcome the difficulties of high energy consumption and lower desorption efficiency in carbon dioxide (CO<sub>2</sub>) regeneration processes of traditional chemical absorbents. In this work, a poly-ether solvent poly(oxymethylene) dimethyl ethers (PODE<sub>3-5</sub>) was introduced as phase separation agent in the anhydrous solution of primary amine 2-(2-aminoethoxy) ethanol (DGA) and dimethyl sulfoxide (DMSO). The optimal DGA/PODE<sub>3-5</sub>/DMSO biphasic absorbent could have a CO<sub>2</sub> capacity of 0.60 mol/mol, with 94.2 % of the charged CO<sub>2</sub> concentrated in the lower phase that representing only 48.1 % of the total liquid volume. And the DGA/PODE<sub>3-5</sub>/DMSO biphasic absorbent had a high CO<sub>2</sub> desorption efficiency of up to 90 % in 30 min and a stable cycling capacity of 0.54 mol/mol. Further, the products and reaction mechanism of CO<sub>2</sub> absorption process were analyzed based on the results of <sup>13</sup>C NMR. The phase separation was triggered by the polarity enhancement of products and the affinity difference to products between PODE<sub>3-5</sub> and DMSO. Particularly, the regeneration energy requirement of the DGA/PODE<sub>3-5</sub>/DMSO biphasic absorbent was 1.90 GJ ton<sup>-1</sup> CO<sub>2</sub>, which is 51.1 % less than 30 wt% MEA-H<sub>2</sub>O solution.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129749
Uranium (U) is a chemical and radioactive groundwater contaminant that needs to be regulated in drinking water to avoid health hazards. In this study, we have investigated the mechanisms underlying ultrafiltration (UF) process, a low energy-intensive technology, for the removal of uranium from contaminated groundwater, in the presence of dissolved organic matter (i.e. Humic Acid [HA]) under environmentally-relevant conditions representative of regional scenario of Punjab, India. Stirred cell UF experiments with aqueous solutions containing uranium were performed with five different UF membranes with molecular weight cut off (MWCO) ranging from 1 kDa to 30 kDa at a pH of 8.5 that represented ambient groundwater scenario. In the absence of HA, the U(VI) removal was highest for the UF membrane with the lowest MWCO (i.e. 1 kDa) and vice-versa. Further, the effect of various solution parameters viz. pH, concentration of HA, and salinity have been studied using three different UF membranes viz. 5 kDa, 10 kDa, and 30 kDa. Uranium rejection was found to be maximum at pH 5.5 with ca. 97 %, 94 %, and 87 % rejection for 5 kDa, 10 kDa, and 30 kDa membranes, respectively. Further, U(VI) speciation results of the hydrogeochemical model corroborated that the removal of U(VI) in the presence of HA was highly dependent on feed solution pH. Moreover, U(VI) removal increased significantly with an increase in HA concentration, indicating the dominant role of U(VI)-HA complexes. Further, it was observed that increasing the salinity levels to 100 mM in the feed solution (i.e. semi-brackish water scenario) decreased U(VI) rejection primarily due to the charge screening effect. Our results show that using the UF separation process, the World Health Organization’s drinking water guideline value of 30 µg of U L−1 could be achieved in U(VI) contaminated groundwater that contains significant HA levels.
{"title":"Influence of dissolved organic matter on U(VI) removal at varying hydrogeochemical scenarios in ultrafiltration process","authors":"","doi":"10.1016/j.seppur.2024.129749","DOIUrl":"10.1016/j.seppur.2024.129749","url":null,"abstract":"<div><div>Uranium (U) is a chemical and radioactive groundwater contaminant that needs to be regulated in drinking water to avoid health hazards. In this study, we have investigated the mechanisms underlying ultrafiltration (UF) process, a low energy-intensive technology, for the removal of uranium from contaminated groundwater, in the presence of dissolved organic matter (i.e. Humic Acid [HA]) under environmentally-relevant conditions representative of regional scenario of Punjab, India. Stirred cell UF experiments with aqueous solutions containing uranium were performed with five different UF membranes with molecular weight cut off (MWCO) ranging from 1 kDa to 30 kDa at a pH of 8.5 that represented ambient groundwater scenario. In the absence of HA, the U(VI) removal was highest for the UF membrane with the lowest MWCO (i.e. 1 kDa) and vice-versa. Further, the effect of various solution parameters viz. pH, concentration of HA, and salinity have been studied using three different UF membranes viz. 5 kDa, 10 kDa, and 30 kDa. Uranium rejection was found to be maximum at pH 5.5 with ca. 97 %, 94 %, and 87 % rejection for 5 kDa, 10 kDa, and 30 kDa membranes, respectively. Further, U(VI) speciation results of the hydrogeochemical model corroborated that the removal of U(VI) in the presence of HA was highly dependent on feed solution pH. Moreover, U(VI) removal increased significantly with an increase in HA concentration, indicating the dominant role of U(VI)-HA complexes. Further, it was observed that increasing the salinity levels to 100 mM in the feed solution (i.e. semi-brackish water scenario) decreased U(VI) rejection primarily due to the charge screening effect. Our results show that using the UF separation process, the World Health Organization’s drinking water guideline value of 30 µg of U L<sup>−1</sup> could be achieved in U(VI) contaminated groundwater that contains significant HA levels.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129846
The addition of organic carbon sources into the culture medium represents an effective strategy for microalgae cultivation. However, its influence on the subsequent flocculation process remains poorly understood. In this study, four representative organic carbon sources were supplemented to microalgal cultures with the aim of evaluating their potential to enhance biomass accumulation, optimize fatty acid composition and improve phototolerance. The results demonstrated that the addition of ethanol, sodium acetate, glucose and fructose to the cultures resulted in extracellular protein contents of 90.9, 125.7, 67.5 and 46.0 mg/g, respectively, compared to 36.8 mg/g observed in the control culture with pure BG-11 medium. The addition of organic carbon sources led to alterations in protein content and the composition ratio of charged groups within the extracellular polymeric substances of microalgae, which in turn influenced the flocculation process. This study provides valuable insights into the selection of appropriate organic carbon sources for promoting microalgal growth and clarifies the flocculation mechanisms under various carbon utilization strategies.
{"title":"Different organic carbon sources affect microalgal growth and extracellular polymeric substances synthesis to trigger biomass flocculation process","authors":"","doi":"10.1016/j.seppur.2024.129846","DOIUrl":"10.1016/j.seppur.2024.129846","url":null,"abstract":"<div><div>The addition of organic carbon sources into the culture medium represents an effective strategy for microalgae cultivation. However, its influence on the subsequent flocculation process remains poorly understood. In this study, four representative organic carbon sources were supplemented to microalgal cultures with the aim of evaluating their potential to enhance biomass accumulation, optimize fatty acid composition and improve phototolerance. The results demonstrated that the addition of ethanol, sodium acetate, glucose and fructose to the cultures resulted in extracellular protein contents of 90.9, 125.7, 67.5 and 46.0 mg/g, respectively, compared to 36.8 mg/g observed in the control culture with pure BG-11 medium. The addition of organic carbon sources led to alterations in protein content and the composition ratio of charged groups within the extracellular polymeric substances of microalgae, which in turn influenced the flocculation process. This study provides valuable insights into the selection of appropriate organic carbon sources for promoting microalgal growth and clarifies the flocculation mechanisms under various carbon utilization strategies.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129766
Marine recirculating aquaculture systems (marine RAS) are increasingly utilized for their high productivity and minimal environmental impact. However, effective nutrient management and biosecurity measures remain crucial for sustainable operation of marine RAS. This study successfully established a simultaneous nitrification and denitrification (SND) process using a biofloc technology (BFT)–ultrafiltration (UF) combined approach. A stable autotrophic marine nitrification system was rapidly initiated within 23 days using a ceramic ring (CR)–granular activated carbon (GAC)–UF process (CGUF), followed by the substitution of polyhydroxyalkanoates (PHA) for GAC filter to achieve rapid start-up of SND in 24 h (CG/PUF). Soluble reactive phosphate (SRP) was removed in-situ via biofloc adsorption. The co-existence of ammonia-oxidizing archaea (Candidatus_Nitrosopumilus) and denitrifying bacteria (Stenotrophomonas, Ruegeria and Ilumatobacter) synergistic promoted the SND start-up in CG/PUF process. Stenotrophomonas emerged as the keystone species which closely linked to amoA/B/C, hao and nosZ genes (p < 0.05). The CG/PUF process effectively enhanced the biosecurity of marine RAS, with 100 % elimination of potential pathogens (Vibrio and Tenacibaculum). UF membrane could maintain fluxes at 15 L∙ m−2∙ h−1 (LMH) for 180 days, with a 2-day intermittent hydraulic flushing keeping transmembrane pressure below 50 kPa. These findings provide insights for broader application of BFT–UF combined process in marine RAS.
{"title":"Innovative approaches for enhanced nutrient (N and P) removal and biosecurity in marine recirculating aquaculture systems using biofloc and ultrafiltration combined systems","authors":"","doi":"10.1016/j.seppur.2024.129766","DOIUrl":"10.1016/j.seppur.2024.129766","url":null,"abstract":"<div><div>Marine recirculating aquaculture systems (marine RAS) are increasingly utilized for their high productivity and minimal environmental impact. However, effective nutrient management and biosecurity measures remain crucial for sustainable operation of marine RAS. This study successfully established a simultaneous nitrification and denitrification (SND) process using a biofloc technology (BFT)–ultrafiltration (UF) combined approach. A stable autotrophic marine nitrification system was rapidly initiated within 23 days using a ceramic ring (CR)–granular activated carbon (GAC)–UF process (CGUF), followed by the substitution of polyhydroxyalkanoates (PHA) for GAC filter to achieve rapid start-up of SND in 24 h (CG/PUF). Soluble reactive phosphate (SRP) was removed in-situ via biofloc adsorption. The co-existence of ammonia-oxidizing archaea (<em>Candidatus_Nitrosopumilus</em>) and denitrifying bacteria (<em>Stenotrophomonas</em>, <em>Ruegeria</em> and <em>Ilumatobacter</em>) synergistic promoted the SND start-up in CG/PUF process. <em>Stenotrophomonas</em> emerged as the keystone species which closely linked to <em>amoA/B/C</em>, <em>hao</em> and <em>nosZ</em> genes (<em>p</em> < 0.05). The CG/PUF process effectively enhanced the biosecurity of marine RAS, with 100 % elimination of potential pathogens (<em>Vibrio</em> and <em>Tenacibaculum</em>). UF membrane could maintain fluxes at 15 L∙ m<sup>−2</sup>∙ h<sup>−1</sup> (LMH) for 180 days, with a 2-day intermittent hydraulic flushing keeping transmembrane pressure below 50 kPa. These findings provide insights for broader application of BFT–UF combined process in marine RAS.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129792
Calixarene possessing advantages of small intrinsic cavity size, small particle dimension, and facile dispersion or dissolution in common solvents, is promising filler candidates in mixed matrix membranes (MMMs) for gas separation. Herein, the supramolecular C-propylpyrogallol[4]arene (PgC3) was successfully synthesized via a phenolic resin condensation reaction. It was then incorporated into a polyether-polyamide block copolymer (Pebax-1657) to prepare mixed matrix membranes (MMMs) with varying PgC3 loadings for CO2/N2 separation. The formation of hydrogen bonds between PgC3 and Pebax facilitated the uniform dispersion of PgC3 within the polymer matrix, enhancing interfacial compatibility. The incorporation of PgC3 significantly enhanced the CO2/N2 selectivity of the Pebax while preserving its permeability. The 1 wt% PgC3/Pebax MMMs performs the best CO2/N2 selectivity of 58.6, substantially higher than that of pristine Pebax membrane (32.4). This improvement can be attributed to the strong affinity between the abundant –OH groups in PgC3 and CO2 molecules. Moreover, the PgC3/Pebax MMMs exhibited exceptional stability under operating pressures of up to 5 bar, maintaining its performance consistently throughout a demanding100-hour test. The good separation performance together with the excellent stability enables PgC3 a promising filler in MMMs for CO2/N2 or other gas separations.
{"title":"Novel mixed matrix membranes containing calixarene for enhanced CO2/N2 separation","authors":"","doi":"10.1016/j.seppur.2024.129792","DOIUrl":"10.1016/j.seppur.2024.129792","url":null,"abstract":"<div><div>Calixarene possessing advantages of small intrinsic cavity size, small particle dimension, and facile dispersion or dissolution in common solvents, is promising filler candidates in mixed matrix membranes (MMMs) for gas separation. Herein, the supramolecular C-propylpyrogallol[4]arene (PgC<sub>3</sub>) was successfully synthesized via a phenolic resin condensation reaction. It was then incorporated into a polyether-polyamide block copolymer (Pebax-1657) to prepare mixed matrix membranes (MMMs) with varying PgC<sub>3</sub> loadings for CO<sub>2</sub>/N<sub>2</sub> separation. The formation of hydrogen bonds between PgC<sub>3</sub> and Pebax facilitated the uniform dispersion of PgC<sub>3</sub> within the polymer matrix, enhancing interfacial compatibility. The incorporation of PgC<sub>3</sub> significantly enhanced the CO<sub>2</sub>/N<sub>2</sub> selectivity of the Pebax while preserving its permeability. The 1 wt% PgC<sub>3</sub>/Pebax MMMs performs the best CO<sub>2</sub>/N<sub>2</sub> selectivity of 58.6, substantially higher than that of pristine Pebax membrane (32.4). This improvement can be attributed to the strong affinity between the abundant –OH groups in PgC<sub>3</sub> and CO<sub>2</sub> molecules. Moreover, the PgC<sub>3</sub>/Pebax MMMs exhibited exceptional stability under operating pressures of up to 5 bar, maintaining its performance consistently throughout a demanding100-hour test. The good separation performance together with the excellent stability enables PgC<sub>3</sub> a promising filler in MMMs for CO<sub>2</sub>/N<sub>2</sub> or other gas separations.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129853
Porous carbon membrane (PCM) derived from MIL-88B-Fe with the ability of in-situ generation of hydroxyl radical was introduced to electro-enhanced aerobic membrane bioreactor (EMBR) for membrane fouling mitigation and wastewater quality improvement. The resultant PCM obtained with the calcination temperature of 1000 °C owned significant enhancement on hydrophilic and conductive properties, which helped PCM under −1.2 V could completely remove 10 mg/L bovine serum albumin with 2.5 % membrane flux loss rate. During the 76-day operation of EMBR, the extracellular polymeric substances could be suppressed for depositing on the −1.2 V enhanced PCM due to the combined effect of electrostatic barrier and OH oxidation. The pollutant intensity of total cells, polysaccharides and proteins were all reduced on PCM with −1.2 V. After operation, 36.0 % of cake layer pores was blocked in EMBR by total cells, polysaccharides and proteins. However, it was accounted for 69.8 % of the control group. Above results explained why the EMBR owned an always lower transmembrane pressure. Meanwhile, the pollutants removal rates of COD and NH4+-N were as high as 95 % and 98 % with electro-enhanced filtration, respectively, which is attributed to the collaborated effect from electrochemical effect and significantly increased microbial species related to organic pollutants removal, such as Azohydromonas, Thermomonas.
{"title":"Electro-Fenton enhanced MBR for fouling alleviation based on MIL-88B-Fe derived carbon membrane with in-situ generated OH","authors":"","doi":"10.1016/j.seppur.2024.129853","DOIUrl":"10.1016/j.seppur.2024.129853","url":null,"abstract":"<div><div>Porous carbon membrane (PCM) derived from MIL-88B-Fe with the ability of in-situ generation of hydroxyl radical was introduced to electro-enhanced aerobic membrane bioreactor (EMBR) for membrane fouling mitigation and wastewater quality improvement. The resultant PCM obtained with the calcination temperature of 1000 °C owned significant enhancement on hydrophilic and conductive properties, which helped PCM under −1.2 V could completely remove 10 mg/L bovine serum albumin with 2.5 % membrane flux loss rate. During the 76-day operation of EMBR, the extracellular polymeric substances could be suppressed for depositing on the −1.2 V enhanced PCM due to the combined effect of electrostatic barrier and <sup><img></sup>OH oxidation. The pollutant intensity of total cells, polysaccharides and proteins were all reduced on PCM with −1.2 V. After operation, 36.0 % of cake layer pores was blocked in EMBR by total cells, polysaccharides and proteins. However, it was accounted for 69.8 % of the control group. Above results explained why the EMBR owned an always lower transmembrane pressure. Meanwhile, the pollutants removal rates of COD and NH<sub>4</sub><sup>+</sup>-N were as high as 95 % and 98 % with electro-enhanced filtration, respectively, which is attributed to the collaborated effect from electrochemical effect and significantly increased microbial species related to organic pollutants removal, such as <em>Azohydromonas</em>, <em>Thermomonas</em>.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-09-23DOI: 10.1016/j.seppur.2024.129844
The sintering aggregation of carbon material (ZIF-N-C-600), as well as the tendency towards agglomeration and oxidation of zero-valent iron nanoparticles (Fe0) limit their applications in advanced oxidation processes. Hence, a flower-like Fe0@ZIF-N-C-600 was rationally constructed by facile one-step self-assembly to ameliorate peroxydisulfate (PDS) activation. The polyhedral ZIF-N-C-600 aggregates were exfoliated into thinner porous nanosheets and Fe0 nanoparticles were effectively dispersed and anchored onto ZIF-N-C-600. 96.7 % of metronidazole (MNZ) was eliminated by the Fe0@ZIF-N-C-600/PDS system, and the removal reaction rate constant k values were 2 and 2.55 times as high as Fe0@ZIF/PDS and Fe0/PDS, respectively. Fe0, defective sites, C=O and pyridinic N were identified as the active sites promoting PDS activation to produce ·OH, SO4·-, ·O2– and 1O2 for synergistic oxidative elimination of MNZ. The formation rate of ·OH was calculated to be 4.62 times higher than that of the SO4·- by multivariate nonlinear fitting, and the ·OH contributes up to 63.5 %. Fe0@ZIF-N-C-600/PDS system possesses excellent tolerance and selectivity to complicated water bodies, and the effective continuous degradation was achieved in a self-made catalytic reactor. Moreover, DFT calculations and LC-MS analysis were applied to deduce possible pathways for MNZ degradation. This work offers an effective strategy to regulate the morphology of sintered carbon materials and improve the application of metal nanoparticles in advanced oxidation processes.
{"title":"One-step self-assembled ZIF-derived flower-like carbon enhances reactivity of zero-valent iron during persulfate activation","authors":"","doi":"10.1016/j.seppur.2024.129844","DOIUrl":"10.1016/j.seppur.2024.129844","url":null,"abstract":"<div><div>The sintering aggregation of carbon material (ZIF-N-C-600), as well as the tendency towards agglomeration and oxidation of zero-valent iron nanoparticles (Fe<sup>0</sup>) limit their applications in advanced oxidation processes. Hence, a flower-like Fe<sup>0</sup>@ZIF-N-C-600 was rationally constructed by facile one-step self-assembly to ameliorate peroxydisulfate (PDS) activation. The polyhedral ZIF-N-C-600 aggregates were exfoliated into thinner porous nanosheets and Fe<sup>0</sup> nanoparticles were effectively dispersed and anchored onto ZIF-N-C-600. 96.7 % of metronidazole (MNZ) was eliminated by the Fe<sup>0</sup>@ZIF-N-C-600/PDS system, and the removal reaction rate constant k values were 2 and 2.55 times as high as Fe<sup>0</sup>@ZIF/PDS and Fe<sup>0</sup>/PDS, respectively. Fe<sup>0</sup>, defective sites, C=O and pyridinic N were identified as the active sites promoting PDS activation to produce ·OH, SO<sub>4</sub>·<sup>-</sup>, ·O<sub>2</sub><sup>–</sup> and <sup>1</sup>O<sub>2</sub> for synergistic oxidative elimination of MNZ. The formation rate of ·OH was calculated to be 4.62 times higher than that of the SO<sub>4</sub>·<sup>-</sup> by multivariate nonlinear fitting, and the ·OH contributes up to 63.5 %. Fe<sup>0</sup>@ZIF-N-C-600/PDS system possesses excellent tolerance and selectivity to complicated water bodies, and the effective continuous degradation was achieved in a self-made catalytic reactor. Moreover, DFT calculations and LC-MS analysis were applied to deduce possible pathways for MNZ degradation. This work offers an effective strategy to regulate the morphology of sintered carbon materials and improve the application of metal nanoparticles in advanced oxidation processes.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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