Pub Date : 2024-11-19DOI: 10.1016/j.seppur.2024.130585
Zifang Chi, Xinyang Liu, Huai Li
The compound pollution of nitrate and hexavalent chromium (Cr(VI)) in groundwater poses a serious hazard to human health and ecology. The use of H2-connected graphene oxide loaded nano zero-valent iron (rGO/nZVI) chemical reduction coupled with hydrogen autotrophic bioreduction system is expected to reduce the economic cost and alleviate the problem of gas blockage. In this study, we investigated the process and mechanism of the removal of NO3–/Cr(VI) compound pollution by rGO/nZVI coupled HAM under weak magnetic field (WMF). The results showed that rGO/nZVI coupled HAM system had the highest removal of NO3– (93.8 %), and the allocation ratio of chemical reduction to biological reduction of nitrate was about 4:1. Under the compound pollution conditions, the removal of Cr(VI) in the coupled system could reach 100 %. The abiotic reaction mechanism should be the main pathway for Cr(VI) removal, and the ratio of chemical reduction to biological reduction was 99:1 within 24 h. The results showed that the chemical reduction and biological reduction of Cr(VI) in the coupled system was the most effective way to remove Cr(VI). High N2 conversion of rGO/nZVI coupled with HAM system at 30 mT was obtained (66.98 % and 43.17 %) at NO3– and NO3–/Cr(VI) composite contamination systems, respectively. The presence of WMF corroded rGO/nZVI towards lepidocrocite moving the denitrification process towards harmlessness (high N2 selectivity). This finding provides a theoretical basis of the coupled system of rGO/nZVI and HAM for the groundwater compound pollution removal.
{"title":"Enhanced Cr(VI) and nitrate reduction using rGO/nZVI coupled hydrogen autotrophs under weak magnetic field: Performance and mechanisms","authors":"Zifang Chi, Xinyang Liu, Huai Li","doi":"10.1016/j.seppur.2024.130585","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130585","url":null,"abstract":"The compound pollution of nitrate and hexavalent chromium (Cr(VI)) in groundwater poses a serious hazard to human health and ecology. The use of H<sub>2</sub>-connected graphene oxide loaded nano zero-valent iron (rGO/nZVI) chemical reduction coupled with hydrogen autotrophic bioreduction system is expected to reduce the economic cost and alleviate the problem of gas blockage. In this study, we investigated the process and mechanism of the removal of NO<sub>3</sub><sup>–</sup>/Cr(VI) compound pollution by rGO/nZVI coupled HAM under weak magnetic field (WMF). The results showed that rGO/nZVI coupled HAM system had the highest removal of NO<sub>3</sub><sup>–</sup> (93.8 %), and the allocation ratio of chemical reduction to biological reduction of nitrate was about 4:1. Under the compound pollution conditions, the removal of Cr(VI) in the coupled system could reach 100 %. The abiotic reaction mechanism should be the main pathway for Cr(VI) removal, and the ratio of chemical reduction to biological reduction was 99:1 within 24 h. The results showed that the chemical reduction and biological reduction of Cr(VI) in the coupled system was the most effective way to remove Cr(VI). High N<sub>2</sub> conversion of rGO/nZVI coupled with HAM system at 30 mT was obtained (66.98 % and 43.17 %) at NO<sub>3</sub><sup>–</sup> and NO<sub>3</sub><sup>–</sup>/Cr(VI) composite contamination systems, respectively. The presence of WMF corroded rGO/nZVI towards lepidocrocite moving the denitrification process towards harmlessness (high N<sub>2</sub> selectivity). This finding provides a theoretical basis of the coupled system of rGO/nZVI and HAM for the groundwater compound pollution removal.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"11 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670892","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 : 2024-11-19DOI: 10.1016/j.seppur.2024.130556
Shuyi Liu, Yinghao Xue, Yan Jia, Hanxue Wang, Qing Nie, Jianwei Fan
Catalytic oxidation of carbon monoxide (CO) has gained increasing interest in recent years due to its promising applications. Cerium-based catalysts have been widely employed in CO oxidation processes due to their reversible oxygen storage/release capacity (OSC), excellent redox activity, and the most abundant rare earth element in the crust (46 ppm). However, conventional CeO2 catalysts still face challenges of insufficient activity and poor stability. Herein, strategies to enhance the activity of CeO2 catalysts are detailed, including crystal facet engineering, metal-support modification, and heteroatom doping. In conclusion, these strategies aim to increase the number of oxygen vacancies, optimize surface active sites, and strengthen the metal-support interaction, thereby significantly improving the activity of catalytic CO oxidation.
近年来，一氧化碳（CO）的催化氧化因其广阔的应用前景而受到越来越多的关注。铈基催化剂具有可逆的储氧/释氧能力（OSC）、出色的氧化还原活性以及地壳中最丰富的稀土元素（46 ppm），因此被广泛应用于一氧化碳氧化过程。然而，传统的 CeO2 催化剂仍然面临着活性不足和稳定性差的挑战。本文详细介绍了提高 CeO2 催化剂活性的策略，包括晶面工程、金属支架改性和杂原子掺杂。总之，这些策略旨在增加氧空位的数量、优化表面活性位点以及加强金属与支撑物之间的相互作用，从而显著提高催化 CO 氧化的活性。
{"title":"Catalytic CO oxidation on CeO2-based materials: Modification strategies, structure-performance relationships, challenges and prospects","authors":"Shuyi Liu, Yinghao Xue, Yan Jia, Hanxue Wang, Qing Nie, Jianwei Fan","doi":"10.1016/j.seppur.2024.130556","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130556","url":null,"abstract":"Catalytic oxidation of carbon monoxide (CO) has gained increasing interest in recent years due to its promising applications. Cerium-based catalysts have been widely employed in CO oxidation processes due to their reversible oxygen storage/release capacity (OSC), excellent redox activity, and the most abundant rare earth element in the crust (46 ppm). However, conventional CeO<sub>2</sub> catalysts still face challenges of insufficient activity and poor stability. Herein, strategies to enhance the activity of CeO<sub>2</sub> catalysts are detailed, including crystal facet engineering, metal-support modification, and heteroatom doping. In conclusion, these strategies aim to increase the number of oxygen vacancies, optimize surface active sites, and strengthen the metal-support interaction, thereby significantly improving the activity of catalytic CO oxidation.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"10 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670922","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}
High-efficiency elimination of uranium was a research hotspot from the aspect of nuclear energy development. Metal chelators and porous materials were two cutting-edge technologies for the recovery and separation of uranium from wastewater. However, there was only limited success in transferring the metal coordination function of metal chelators to chemically stable host materials. Herein, oxamic acid (OxA) and glycine (Gly) functionalized MOF-808 were prepared by a simple solvent-assisted ligand incorporation method and used for uranium removal. The ordered porous structure of MOFs provided rapid diffusion channels, and the introduction of amino acids on Zr6 nodes endowed MOF-808 channels more functional groups with strong binding ability and high hydrophily. The MOF-808@OxA exhibited higher elimination ability (qmax = 370.76 mg·g−1), rapider elimination rate (∼40 min), and higher selectivity than those of MOF-808@Gly and original MOF-808 at pH = 5. Particularly, density functional theory calculations revealed that MOF-808@OxA had a stronger affinity for uranium compared to MOF-808@Gly due to the synergistic effect of C = O and –NH2 groups. Thus, this study provided a feasible strategy for modifying MOFs and a promising prospect for MOF-based materials to eliminate uranium from wastewater.
{"title":"Exploiting the nodes of metal-organic framework by grafting functional organic molecules for synergistic uranium extraction","authors":"Zixuan Ma, Chang Sun, Danyan Lin, Wen Yao, Hairui Hou, Dedong Wu, Xinrong Guo, Xin Yu, Xiangxue Wang","doi":"10.1016/j.seppur.2024.130607","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130607","url":null,"abstract":"High-efficiency elimination of uranium was a research hotspot from the aspect of nuclear energy development. Metal chelators and porous materials were two cutting-edge technologies for the recovery and separation of uranium from wastewater. However, there was only limited success in transferring the metal coordination function of metal chelators to chemically stable host materials. Herein, oxamic acid (OxA) and glycine (Gly) functionalized MOF-808 were prepared by a simple solvent-assisted ligand incorporation method and used for uranium removal. The ordered porous structure of MOFs provided rapid diffusion channels, and the introduction of amino acids on Zr<sub>6</sub> nodes endowed MOF-808 channels more functional groups with strong binding ability and high hydrophily. The MOF-808@OxA exhibited higher elimination ability (<em>q</em><sub>max</sub> = 370.76 mg·g<sup>−1</sup>), rapider elimination rate (∼40 min), and higher selectivity than those of MOF-808@Gly and original MOF-808 at pH = 5. Particularly, density functional theory calculations revealed that MOF-808@OxA had a stronger affinity for uranium compared to MOF-808@Gly due to the synergistic effect of C = O and –NH<sub>2</sub> groups. Thus, this study provided a feasible strategy for modifying MOFs and a promising prospect for MOF-based materials to eliminate uranium from wastewater.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670891","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}
As the electric vehicle sector experiences swift expansion, there is a notable surge in the quantity of depleted lithium-ion batteries (LIBs). Effective management of these batteries involves separating key metals to enable resource recovery and reuse. The leachate from LIBs (L-LIBs) primarily contains Co(II) and Li(I), and selective extraction of Co(II) is crucial for reducing resource waste and promoting sustainability. In this study, a cost-effective and structurally stable Na-based type A molecular sieve (NaA) MOFs composite, NaA-MOFs(Al), was compounded through a straightforward two-step method for the selective extraction of Co(II) from L-LIBs. The results from the static adsorption trials indicate that the NaA-MOFs(Al) achieves a theoretical saturation point of 435.7 mg/g in its Co(II) adsorptive capacity, surpassing all previously documented values. The material achieved monolayer chemical adsorption through coordination interactions and exhibited excellent selectivity with a Li(I) selectivity coefficient of 328.4. Dynamic separation experiments further demonstrated that NaA-MOFs(Al) could completely separate Co(II) and Li(I), exhibiting a dynamic adsorption capacity of 512.0 mg/g, which aligns closely with the theoretical expectations from the Thomas model. The successful preparation of this new composite material not only reduces the cost of adsorbents but also significantly improves the adsorption capacity and selectivity for Co(II). This advancement provides great potential for the efficient recycling of lithium batteries and contributes to the sustainable development of the new energy industry.
{"title":"Selective separation of Co(II) from leachate of lithium-ion battery cathode material using novel molecular sieve-based MOFs composite NaA-MOFs(Al)","authors":"Chuang Chen, Yue Wang, Qi Zou, Liting Ding, Letian Ji, Jiayi Lu, Yaling Song, Wei Xiong, Guoyuan Yuan","doi":"10.1016/j.seppur.2024.130560","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130560","url":null,"abstract":"As the electric vehicle sector experiences swift expansion, there is a notable surge in the quantity of depleted lithium-ion batteries (LIBs). Effective management of these batteries involves separating key metals to enable resource recovery and reuse. The leachate from LIBs (L-LIBs) primarily contains Co(II) and Li(I), and selective extraction of Co(II) is crucial for reducing resource waste and promoting sustainability. In this study, a cost-effective and structurally stable Na-based type A molecular sieve (NaA) MOFs composite, NaA-MOFs(Al), was compounded through a straightforward two-step method for the selective extraction of Co(II) from L-LIBs. The results from the static adsorption trials indicate that the NaA-MOFs(Al) achieves a theoretical saturation point of 435.7 mg/g in its Co(II) adsorptive capacity, surpassing all previously documented values. The material achieved monolayer chemical adsorption through coordination interactions and exhibited excellent selectivity with a Li(I) selectivity coefficient of 328.4. Dynamic separation experiments further demonstrated that NaA-MOFs(Al) could completely separate Co(II) and Li(I), exhibiting a dynamic adsorption capacity of 512.0 mg/g, which aligns closely with the theoretical expectations from the Thomas model. The successful preparation of this new composite material not only reduces the cost of adsorbents but also significantly improves the adsorption capacity and selectivity for Co(II). This advancement provides great potential for the efficient recycling of lithium batteries and contributes to the sustainable development of the new energy industry.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"53 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691009","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}
Constructing S-scheme heterojunctions with a robust internal electric field (IEF) to enhance the photocatalytic degradation of chlorinated volatile organic compounds (Cl-VOCs) presents a significant challenge. Herein, an innovative S-scheme heterojunction of N-doped titanium dioxide (TiO2) and tungsten trioxide (WO3) with abundant oxygen vacancies (OVs) was first synthesized and manipulated via an eco-friendly two-step plasma. The charge transfer pathway between TiO2 and WO3 was analyzed using UV–Vis DRS, XPS, UPS, and EPR measurements, confirming the successful formation of the S-scheme heterojunction. Interestingly, two novel types of IEF: stream-type and waterfall-type were first proposed to distinguish the IEF strength before and after regulation. Under visible light, 5NTW with the optimal ratio (4.66 at% nitrogen and 5 wt% WO3) achieved the highest degradation efficiency and carbon dioxide mineralization rate of 95.4% and 94.1% for chlorobenzene, respectively. The performance enhancement was attributed to the fact that N-doping modifies the electronic structure and work function of TiO2, enhancing the Fermi level difference (ΔEf) with WO3. Meanwhile, the plasma treatment roughened the surface topography of the catalyst and increased the content of OVs, which serve as charge traps and bolster active sites. These synergies led to a transformation from a stream-type IEF of TW to a waterfall-type IEF of 5NTW. KPFM, zeta potential tests, and DFT calculations confirmed that the IEF strength and the number of electron transfers in the waterfall-type IEF are 3.17 and 2.04 times greater, respectively, than those in the stream-type IEF. This strategy transcends the limitations of previous work, offering a novel perspective on the integrated optimization of photocatalysts for superior performance and also further broadens the application prospects of nonthermal plasma technology.
{"title":"Plasma-Assisted construction of waterfall-type IEF in N-TiO2/WO3 S-scheme heterojunction for efficient Visible-Light-Driven degradation of Cl-VOCs","authors":"Ran Sun, Yujie Tan, Wei Zhao, Lijie Song, Ruina Zhang, Xingang Liu, Jianyuan Hou, Yuan Yuan, Feng Qin, Danyan Cen, Renxi Zhang","doi":"10.1016/j.seppur.2024.130626","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130626","url":null,"abstract":"Constructing S-scheme heterojunctions with a robust internal electric field (IEF) to enhance the photocatalytic degradation of chlorinated volatile organic compounds (Cl-VOCs) presents a significant challenge. Herein, an innovative S-scheme heterojunction of N-doped titanium dioxide (TiO<sub>2</sub>) and tungsten trioxide (WO<sub>3</sub>) with abundant oxygen vacancies (OVs) was first synthesized and manipulated via an eco-friendly two-step plasma. The charge transfer pathway between TiO<sub>2</sub> and WO<sub>3</sub> was analyzed using UV–Vis DRS, XPS, UPS, and EPR measurements, confirming the successful formation of the S-scheme heterojunction. Interestingly, two novel types of IEF: stream-type and waterfall-type were first proposed to distinguish the IEF strength before and after regulation. Under visible light, 5NTW with the optimal ratio (4.66 at% nitrogen and 5 wt% WO<sub>3</sub>) achieved the highest degradation efficiency and carbon dioxide mineralization rate of 95.4% and 94.1% for chlorobenzene, respectively. The performance enhancement was attributed to the fact that N-doping modifies the electronic structure and work function of TiO<sub>2</sub>, enhancing the Fermi level difference (ΔE<sub>f</sub>) with WO<sub>3</sub>. Meanwhile, the plasma treatment roughened the surface topography of the catalyst and increased the content of OVs, which serve as charge traps and bolster active sites. These synergies led to a transformation from a stream-type IEF of TW to a waterfall-type IEF of 5NTW. KPFM, zeta potential tests, and DFT calculations confirmed that the IEF strength and the number of electron transfers in the waterfall-type IEF are 3.17 and 2.04 times greater, respectively, than those in the stream-type IEF. This strategy transcends the limitations of previous work, offering a novel perspective on the integrated optimization of photocatalysts for superior performance and also further broadens the application prospects of nonthermal plasma technology.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"47 2 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673947","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 : 2024-11-19DOI: 10.1016/j.seppur.2024.130584
Durga Prasad Kotla, Venkateswara Rao Anna, Seepana Praveenkumar, Sayed M. Saleh, S. Shanmugan
Sugarcane (Saccharum officinarum L. (SO)), a widely cultivated tropical crop, provides a sustainable source of raw material for producing TiO2 nanoparticles (T). This study investigates the potential of these nanoparticles to improve the efficiency of Single Basin Solar Distiller (SBD), which is devices that harness solar energy to purify water. A novel SBD design featuring a unique basin shape and aluminum silver bottles (AS) filled with TiO2 nanofluid (ASTSO) was constructed and tested in Vijayawada, India. The AS arranged in a bowl-like configuration and filled with nanofluid, significantly enhance heat absorption. Moreover, the SBD’s unique basin shape increases the evaporative surface area by 26 % compared to conventional solar stills (CSS). The SBD demonstrated a notable increase in water production, achieving yields of 8.437 kg/m2/day in summer and 8.087 kg/m2/day in winter. This corresponds to a daily efficiency (ASTSO) of 58.73 % in summer and 47.52 % in winter, representing a substantial improvement over traditional solar stills. The enhanced performance is attributed to the improved thermal properties of the nanofluid, which accelerate the evaporation and condensation processes. The nanofluids higher thermal conductivity and heat absorption capacity contribute to the increased water production. A comparative economic analysis of the SBD and CSS was conducted, revealing that the projected cost of distilled water from both systems is expected to remain stable at Rs 1.93/kg and Rs 2.19/kg, respectively, over the next decade. This research presents a promising approach to enhance the efficiency and productivity of solar stills, providing a sustainable and cost-effective solution for water purification. Future research will focus on optimizing nanofluid concentrations, exploring other nanomaterials, and integrating advanced solar stills with renewable energy technologies to develop sustainable water purification systems.
{"title":"Optimizing solar still performance: A study of TiO2 nanofluid derived from Saccharum officinarum L.","authors":"Durga Prasad Kotla, Venkateswara Rao Anna, Seepana Praveenkumar, Sayed M. Saleh, S. Shanmugan","doi":"10.1016/j.seppur.2024.130584","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130584","url":null,"abstract":"Sugarcane (Saccharum officinarum L. (SO)), a widely cultivated tropical crop, provides a sustainable source of raw material for producing TiO<sub>2</sub> nanoparticles (T). This study investigates the potential of these nanoparticles to improve the efficiency of Single Basin Solar Distiller (SBD), which is devices that harness solar energy to purify water. A novel SBD design featuring a unique basin shape and aluminum silver bottles (AS) filled with TiO<sub>2</sub> nanofluid (ASTSO) was constructed and tested in Vijayawada, India. The AS arranged in a bowl-like configuration and filled with nanofluid, significantly enhance heat absorption. Moreover, the SBD’s unique basin shape increases the evaporative surface area by 26 % compared to conventional solar stills (CSS). The SBD demonstrated a notable increase in water production, achieving yields of 8.437 kg/m2/day in summer and 8.087 kg/m2/day in winter. This corresponds to a daily efficiency (ASTSO) of 58.73 % in summer and 47.52 % in winter, representing a substantial improvement over traditional solar stills. The enhanced performance is attributed to the improved thermal properties of the nanofluid, which accelerate the evaporation and condensation processes. The nanofluids higher thermal conductivity and heat absorption capacity contribute to the increased water production. A comparative economic analysis of the SBD and CSS was conducted, revealing that the projected cost of distilled water from both systems is expected to remain stable at Rs 1.93/kg and Rs 2.19/kg, respectively, over the next decade. This research presents a promising approach to enhance the efficiency and productivity of solar stills, providing a sustainable and cost-effective solution for water purification. Future research will focus on optimizing nanofluid concentrations, exploring other nanomaterials, and integrating advanced solar stills with renewable energy technologies to develop sustainable water purification systems.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"156 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142690845","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}
Oil droplets are inevitably deposited on the surface of membranes, resulting in membrane contamination during oily sewage separation. To effectively prevent oil fouling, a TiO2@MXene membrane with an ultra-glossy hydrophilic surface was designed via in-situ thermal induction to regulate the membrane surface structure and properties. Through high temperature-induced evolving the Ti valence and the functional groups of Ti3C2Tx, uniform TiO2 nanoparticles were generated in-situ on the Ti3C2Tx surface while altering the surface structure and properties, which considerably improved the hydrophilicity, underwater oleophobic properties, and surface finish of the membrane. Specifically, the TiO2@MXene membrane (MT600) exhibited a low water contact angle of 7.5° and a high underwater oil contact angle of 133.3°. Notably, the oil adhesion force of the membrane was as low as 0.0013 μN, outperforming most oil water separation membranes. Thus, the unique structure and surface properties endowed MT600 membrane with excellent oil retention (TOC removal efficiency of > 95 %) and antipollution ability (permeance decay rates of < 10 %) for oil-in-water emulsion separation. This is because the ultra-glossy hydrophilic and oleophobic surface prompted the formation of a continuous and stable hydration layer on the membrane surface and prevented oil droplets from falling into the membrane grooves. Benefiting from the robust, ultra-glossy surface, the MT600 membrane exhibited excellent long-term durability and reusability (emulsion permeance recovery of > 90 %) in high-salt, highly acidic, and highly alkaline environments. This study opens pathways to realize ultra-glossy membrane surface for the efficient demulsification of small size emulsions and long-lasting, stable oil water separation.
{"title":"In-situ thermally induced formation of an ultra-glossy hydrophilic surface for oil fouling prevention in TiO2@MXene membranes","authors":"Yuqing Sun, Chenye Dai, Jian Lu, Yapeng Zhu, Yingxuan Deng, Xianyin Cai, Dong Zou, Wenheng Jing","doi":"10.1016/j.seppur.2024.130599","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130599","url":null,"abstract":"Oil droplets are inevitably deposited on the surface of membranes, resulting in membrane contamination during oily sewage separation. To effectively prevent oil fouling, a TiO<sub>2</sub>@MXene membrane with an ultra-glossy hydrophilic surface was designed via in-situ thermal induction to regulate the membrane surface structure and properties. Through high temperature-induced evolving the Ti valence and the functional groups of Ti<sub>3</sub>C<sub>2</sub>T<em><sub>x</sub></em>, uniform TiO<sub>2</sub> nanoparticles were generated in-situ on the Ti<sub>3</sub>C<sub>2</sub>T<em><sub>x</sub></em> surface while altering the surface structure and properties, which considerably improved the hydrophilicity, underwater oleophobic properties, and surface finish of the membrane. Specifically, the TiO<sub>2</sub>@MXene membrane (MT600) exhibited a low water contact angle of 7.5° and a high underwater oil contact angle of 133.3°. Notably, the oil adhesion force of the membrane was as low as 0.0013 μN, outperforming most oil water separation membranes. Thus, the unique structure and surface properties endowed MT600 membrane with excellent oil retention (TOC removal efficiency of > 95 %) and antipollution ability (permeance decay rates of < 10 %) for oil-in-water emulsion separation. This is because the ultra-glossy hydrophilic and oleophobic surface prompted the formation of a continuous and stable hydration layer on the membrane surface and prevented oil droplets from falling into the membrane grooves. Benefiting from the robust, ultra-glossy surface, the MT600 membrane exhibited excellent long-term durability and reusability (emulsion permeance recovery of > 90 %) in high-salt, highly acidic, and highly alkaline environments. This study opens pathways to realize ultra-glossy membrane surface for the efficient demulsification of small size emulsions and long-lasting, stable oil water separation.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"67 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694296","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}
The effective removal of elemental mercury (Hg0) is a global challenge due to its toxicity and bioaccumulation threat to public health and ecosystems. Photocatalytic technology by visible light-driven photocatalysts is promising for Hg0 removal. However, effective separation of photocatalyst powders from reaction solution limits its widespread use. To solve the problem, we report for the first time the successful fabrication of recoverable Bi2O2S/Bi5O7I/ZA hydrogel beads for enhanced photocatalytic Hg0 removal in the presence of H2O2. Characterization techniques such as XRD, TEM, EDS, XPS, UV–vis DRS, PL, etc. are employed to understand the physicochemical properties and photoelectric performance of the photocatalysts. The serial BOSI photocatalysts all outperform the single component, which is attributed to the formation of a heterojunction between Bi5O7I and Bi2O2S. The coupling of 2-BOSI-ZA beads with H2O2 shows favorable synergistic effect, with Hg0 removal efficiency in the following order: H2O2 + 2-BOSI-ZA < 2-BOSI-ZA + FSL < H2O2 + 2-BOSI-ZA + FSL. TPC, EIS, and PL tests confirm that the introduction of Bi2O2S effectively suppresses charge carrier recombination. ESR and free radicals capture experiments demonstrate that the main species responsible for removal of Hg0 are •O2– and •OH. Density functional theory calculations exhibit that the internal electric field (IEF) between Bi5O7I and Bi2O2S contributes to the spatial charge separation of the heterojunction. The IEF leads to an S-scheme carrier transfer mechanism at the Bi2O2S/Bi5O7I interface that benefits the carrier separation on Bi5O7I, resulting in an enhanced photocatalytic performance. This work can provide further inspiration for designing hydrogel photocatalysts with an excellent activity in conjunction with oxidants in the field of mercury pollution control.
{"title":"Fabrication of recoverable Bi2O2S/Bi5O7I/ZA hydrogel beads for enhanced photocatalytic Hg0 removal in the presence of H2O2","authors":"Haixing Du, Anchao Zhang, Qianqian Zhang, Yihong Sun, Haowei Zhu, Hua Wang, Zengqiang Tan, Xinmin Zhang, Guoyan Chen","doi":"10.1016/j.seppur.2024.130597","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130597","url":null,"abstract":"The effective removal of elemental mercury (Hg<sup>0</sup>) is a global challenge due to its toxicity and bioaccumulation threat to public health and ecosystems. Photocatalytic technology by visible light-driven photocatalysts is promising for Hg<sup>0</sup> removal. However, effective separation of photocatalyst powders from reaction solution limits its widespread use. To solve the problem, we report for the first time the successful fabrication of recoverable Bi<sub>2</sub>O<sub>2</sub>S/Bi<sub>5</sub>O<sub>7</sub>I/ZA hydrogel beads for enhanced photocatalytic Hg<sup>0</sup> removal in the presence of H<sub>2</sub>O<sub>2</sub>. Characterization techniques such as XRD, TEM, EDS, XPS, UV–vis DRS, PL, etc. are employed to understand the physicochemical properties and photoelectric performance of the photocatalysts. The serial BOSI photocatalysts all outperform the single component, which is attributed to the formation of a heterojunction between Bi<sub>5</sub>O<sub>7</sub>I and Bi<sub>2</sub>O<sub>2</sub>S. The coupling of 2-BOSI-ZA beads with H<sub>2</sub>O<sub>2</sub> shows favorable synergistic effect, with Hg<sup>0</sup> removal efficiency in the following order: H<sub>2</sub>O<sub>2</sub> + 2-BOSI-ZA < 2-BOSI-ZA + FSL < H<sub>2</sub>O<sub>2</sub> + 2-BOSI-ZA + FSL. TPC, EIS, and PL tests confirm that the introduction of Bi<sub>2</sub>O<sub>2</sub>S effectively suppresses charge carrier recombination. ESR and free radicals capture experiments demonstrate that the main species responsible for removal of Hg<sup>0</sup> are <sup>•</sup>O<sub>2</sub><sup>–</sup> and <sup>•</sup>OH. Density functional theory calculations exhibit that the internal electric field (IEF) between Bi<sub>5</sub>O<sub>7</sub>I and Bi<sub>2</sub>O<sub>2</sub>S contributes to the spatial charge separation of the heterojunction. The IEF leads to an S-scheme carrier transfer mechanism at the Bi<sub>2</sub>O<sub>2</sub>S/Bi<sub>5</sub>O<sub>7</sub>I interface that benefits the carrier separation on Bi<sub>5</sub>O<sub>7</sub>I, resulting in an enhanced photocatalytic performance. This work can provide further inspiration for designing hydrogel photocatalysts with an excellent activity in conjunction with oxidants in the field of mercury pollution control.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670890","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}
Volatile organic compounds (VOCs) are important sources of air pollution complex in China and exist as mixtures of different-sized components in industrial exhaust gases. Activated carbon is a type of widely-used adsorbent for VOCs removal, but faced with poor VOCs co-adsorption performance due to competitive adsorption. Herein, an efficient strategy of constructing hierarchical pore configuration was proposed to alleviate competitive adsorption of VOCs with different kinetic diameters and further enhance co-adsorption capacity. The role of hierarchical pore configuration in co-adsorption of typical VOCs toluene and dichloromethane was revealed based on coal-based porous carbon with tunable pore hierarchy. Dynamic adsorption experiments show that micropore-dominant carbon, adsorption capacities of toluene and dichloromethane under co-adsorption dramatically decreased by 14 % and 42 % respectively compared to single component adsorption. However, the loss of adsorption capacity within the hierarchical porous carbon was only 9 % and 14 % under the same conditions. Correlation analyses and molecular dynamics simulations showed that hierarchical porous carbon could induce unique adsorption behavior in which toluene tends to be stored in mesopore and dichloromethane is mainly distributed in micropore, thus effectively reducing the competitive adsorption. Guided by the found mechanism, we further prepared hierarchical porous carbon with high specific surface area and pore volume, based on which adsorption capacity of toluene and dichloromethane under co-adsorption condition was enhanced by more than 50 % compared to micropore-dominant carbon. The relevant mechanism provides a theoretical basis for advancing the optimization of co-adsorption process of mixed VOCs.
{"title":"Revealing the role of hierarchical pore in alleviating competitive adsorption between different-sized VOCs: A mechanistic study using coal-based activated carbon with tunable porous hierarchy","authors":"Yingjian Chen, Zhibin Qu, Fei Sun, Xuhan Li, Jingjie Wang, Junfeng Li, Jihui Gao, Guangbo Zhao","doi":"10.1016/j.seppur.2024.130609","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130609","url":null,"abstract":"Volatile organic compounds (VOCs) are important sources of air pollution complex in China and exist as mixtures of different-sized components in industrial exhaust gases. Activated carbon is a type of widely-used adsorbent for VOCs removal, but faced with poor VOCs co-adsorption performance due to competitive adsorption. Herein, an efficient strategy of constructing hierarchical pore configuration was proposed to alleviate competitive adsorption of VOCs with different kinetic diameters and further enhance co-adsorption capacity. The role of hierarchical pore configuration in co-adsorption of typical VOCs toluene and dichloromethane was revealed based on coal-based porous carbon with tunable pore hierarchy. Dynamic adsorption experiments show that micropore-dominant carbon, adsorption capacities of toluene and dichloromethane under co-adsorption dramatically decreased by 14 % and 42 % respectively compared to single component adsorption. However, the loss of adsorption capacity within the hierarchical porous carbon was only 9 % and 14 % under the same conditions. Correlation analyses and molecular dynamics simulations showed that hierarchical porous carbon could induce unique adsorption behavior in which toluene tends to be stored in mesopore and dichloromethane is mainly distributed in micropore, thus effectively reducing the competitive adsorption. Guided by the found mechanism, we further prepared hierarchical porous carbon with high specific surface area and pore volume, based on which adsorption capacity of toluene and dichloromethane under co-adsorption condition was enhanced by more than 50 % compared to micropore-dominant carbon. The relevant mechanism provides a theoretical basis for advancing the optimization of co-adsorption process of mixed VOCs.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"11 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691011","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 : 2024-11-19DOI: 10.1016/j.seppur.2024.130604
Yu Ni, Ruixin Zhao, Mei Jiang, Dongmei Bi, Jiyan Ma, Yongjun Li
The synergistic mechanism of nitrogen-containing chemicals (NCCs) production was explored from the co-pyrolysis of corn cob and the three major biomass components (cellulose, xylan, and lignin) with urea. Compared to individual pyrolysis, the stability of co-pyrolysis oil was significantly enhanced. The three components showed a synergistic effect during co-pyrolysis. The phenolic compounds generated from lignin interacted with the pyran compounds produced from cellulose or xylan. Especially in the presence of urea, this cross-reaction enhanced the formation of nitrogen-containing heterocycles (NHCs). At 500 ℃, the highest yield of NCCs was observed in the co-pyrolysis oil of corn cob and urea, reaching 47.6 wt%. The NHCs exhibited a selectivity of up to 96.9 wt%. the high concentration of urea promoted the pyrolysis of hemicellulose and cellulose, inhibiting the reaction between cellulose-derived products and free amines to form amines. FT-IR analysis of the char revealed that the addition of urea promoted the decomposition of corn cob, enhancing C–H bond breakdown and dehydrogenation reactions. Finally, a potential formation mechanism for The primary NHCs in corn cob pyrolysis oil was pyridine during the co-pyrolysis of corn cob and urea were proposed. The findings of this paper provide theoretical support for the production of NCCs from biomass through the synergistic interaction of its three components.
{"title":"Synergistic effect of nitrogen-rich pyrolysis of three components and nitrogen transformation mechanism","authors":"Yu Ni, Ruixin Zhao, Mei Jiang, Dongmei Bi, Jiyan Ma, Yongjun Li","doi":"10.1016/j.seppur.2024.130604","DOIUrl":"https://doi.org/10.1016/j.seppur.2024.130604","url":null,"abstract":"The synergistic mechanism of nitrogen-containing chemicals (NCCs) production was explored from the co-pyrolysis of corn cob and the three major biomass components (cellulose, xylan, and lignin) with urea. Compared to individual pyrolysis, the stability of co-pyrolysis oil was significantly enhanced. The three components showed a synergistic effect during co-pyrolysis. The phenolic compounds generated from lignin interacted with the pyran compounds produced from cellulose or xylan. Especially in the presence of urea, this cross-reaction enhanced the formation of nitrogen-containing heterocycles (NHCs). At 500 ℃, the highest yield of NCCs was observed in the co-pyrolysis oil of corn cob and urea, reaching 47.6 wt%. The NHCs exhibited a selectivity of up to 96.9 wt%. the high concentration of urea promoted the pyrolysis of hemicellulose and cellulose, inhibiting the reaction between cellulose-derived products and free amines to form amines. FT-IR analysis of the char revealed that the addition of urea promoted the decomposition of corn cob, enhancing C–H bond breakdown and dehydrogenation reactions. Finally, a potential formation mechanism for The primary NHCs in corn cob pyrolysis oil was pyridine during the co-pyrolysis of corn cob and urea were proposed. The findings of this paper provide theoretical support for the production of NCCs from biomass through the synergistic interaction of its three components.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670888","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：