Separation and Purification Technology最新文献_第3页

Enhanced gravity-driven membrane filtration for purifying roof rainwater using multi-walled carbon nanotubes tuned PVDF hollow fiber membranes 利用多壁碳纳米管调谐聚偏二氟乙烯中空纤维膜增强重力驱动膜过滤技术净化屋顶雨水

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-26 DOI: 10.1016/j.seppur.2024.129869

The collection and reuse of roof rainwater can alleviate water shortage for daily life. In this study, polyvinylidene fluoride hollow fiber membranes tuned with three multi-walled carbon nanotubes (pure MWCNTs, MWCNTs-COOH, and MWCNTs-OH) were prepared using a non-solvent induced phase separation method for gravity-driven membrane filtration to purify roof rainwater. The results showed that the MWCNTs were distributed on the membrane surface and throughout the porous structure of the cross-section, which changed the pore structure parameters and hydrophilicity. The pure water flux of the MWCNTs tuned membranes increased by 152.5 % at 1.0 bar, and the rejection rates of humic acid and bovine serum albumin increased from 97.4 % and 75.7 % to 98.9 % and 96.3 %, respectively. The extended Derjaguin, Landau, Verwey, and Overbeek (xDLVO) theory states that the presence of MWCNTs leads to changes in the physicochemical properties of the membrane surface, resulting in membranes with different anti-fouling behaviors. A gravity-driven membrane filtration test was continuously operated for 100 days, and all membranes removed 25.0–26.7 %, 49.5–53.0 %, and 89.0–93.3 % of total dissolved solids, dissolved organic carbon, and turbidity from roof rainwater, respectively. However, the pure MWCNTs modified membrane with relatively hydrophobic properties showed a 12.4 % increase in flux over the unmodified membrane. Importantly, the presence of the MWCNTs in the membrane changed the microbial diversity in the biofilter cake layer.

屋顶雨水的收集和再利用可缓解日常生活用水短缺的问题。本研究采用非溶剂诱导相分离法制备了含有三种多壁碳纳米管（纯 MWCNTs、MWCNTs-COOH 和 MWCNTs-OH）的聚偏氟乙烯中空纤维膜，用于重力驱动膜过滤净化屋顶雨水。结果表明，MWCNTs 分布在膜表面和整个截面的多孔结构中，改变了孔结构参数和亲水性。在 1.0 巴的压力下，MWCNTs 调谐膜的纯水通量增加了 152.5%，腐植酸和牛血清白蛋白的去除率分别从 97.4% 和 75.7% 增加到 98.9% 和 96.3%。扩展的 Derjaguin、Landau、Verwey 和 Overbeek（xDLVO）理论指出，MWCNT 的存在会导致膜表面的物理化学性质发生变化，从而产生具有不同防污行为的膜。重力驱动膜过滤试验连续运行了 100 天，所有膜分别去除屋顶雨水中 25.0-26.7%、49.5-53.0% 和 89.0-93.3%的总溶解固体、溶解有机碳和浊度。然而，具有相对疏水特性的纯微碳纳米管改性膜比未改性膜的通量增加了 12.4%。重要的是，膜中的 MWCNTs 改变了生物滤饼层中微生物的多样性。

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引用次数: 0

Rational construction p-n heterojunction Ni(OH)2/NiS2 on g-C3N4 nanosheet to promote the charge carriers separation efficiency for boosting photocatalytic hydrogen evolution 在 g-C3N4 纳米片上合理构建 p-n 异质结 Ni(OH)2/NiS2，提高电荷载流子分离效率以促进光催化氢气进化

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-26 DOI: 10.1016/j.seppur.2024.129905

The Ni(OH)₂/NiS₂/g-C₃N₄ hybrid with sandwich-like structure was successfully designed and synthesized through a solvothermal and condensation reflux method. Furthermore, it should be noted that the p-type Ni(OH)₂ was in situ generated on the surface of the n-type NiS₂, because the Ni²⁺ of the Ni(OH)₂ came from the NiS₂. Therefore, the p-n heterojunction was constructed between the interface of the Ni(OH)₂ and NiS₂ in the hybrid. Furthermore, the results revealed the optimized Ni(OH)₂/NiS₂/g-C₃N₄ hybrid displayed superior H₂ evolution property than that of the g-C₃N₄, NiS₂/g-C₃N₄, and Ni(OH)₂/g-C₃N₄ illuminating with visible-light or simulated-sunlight. The apparent quantum yield (AQY) of Ni(OH)₂/NiS₂/g-C₃N₄-6 % at 360, 380 and 400 nm were 1.65 %, 1.31 % and 1.05 %, respectively. Moreover, the resultant Ni(OH)₂/NiS₂/g-C₃N₄-6 % hybrid both displayed satisfactory photochemistry durability. Besides this, according to the microstructure and photoelectric property characterizations, theoretical calculation, and in situ XPS test, the promoted H₂ evolution property of the ternary catalyst was profit from the synergy impact of the particular sandwich-like structure, and p-n heterojunction. Because they could memorably boost the carriers’ separation efficiency, and offer abundant active sites for H₂ production.

通过溶热和冷凝回流法，成功设计并合成了具有三明治结构的Ni(OH)2/NiS2/g-C3N4杂化物。此外，值得注意的是，p 型 Ni(OH)2 是在 n 型 NiS2 表面原位生成的，因为 Ni(OH)2 中的 Ni2+ 来自 NiS2。因此，在杂化物中 Ni（OH）2 和 NiS2 的界面之间构建了 p-n 异质结。此外，研究结果表明，与 g-C3N4、NiS2/g-C3N4 和 Ni(OH)2/g-C3N4 相比，经过优化的 Ni(OH)2/NiS2/g-C3N4 杂化物在可见光或模拟太阳光照射下具有更优越的 H2 演化性能。在 360、380 和 400 纳米波长下，Ni(OH)2/NiS2/g-C3N4-6 % 的表观量子产率（AQY）分别为 1.65 %、1.31 % 和 1.05 %。此外，所得到的 Ni(OH)2/NiS2/g-C3N4-6 % 混合物都显示出令人满意的光化学耐久性。此外，根据微观结构和光电特性表征、理论计算和原位 XPS 测试，三元催化剂促进 H2 演化的特性得益于特殊的三明治状结构和 p-n 异质结的协同作用。因为它们能显著提高载流子的分离效率，并为 H2 的产生提供丰富的活性位点。

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引用次数: 0

Alkoxy-functionalized covalent organic Framework membranes for efficient molecular sieving with high water permeance 用于高效分子筛和高透水性的烷氧基官能化共价有机框架膜

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-26 DOI: 10.1016/j.seppur.2024.129903

The presence of various trace water-soluble organic pollutants, such as dyes, poses significant potential risks to human health and ecosystems. Membrane technology presents a promising and sustainable approach for their removal from aqueous environments. However, the amorphous structure of most commercial membranes makes it challenging to achieve effective separation with high water flux. Here, we present a novel series of hydrophilic COF membranes with different alkoxy sidechain lengths for the first time. These alkoxy sidechain functional COF membranes exhibit efficient rejection of water-soluble organic dyes, including rose bengal (> 50 %), congo red (> 98 %), brilliant blue R250 (> 99 %), and alcian blue (> 99 %). Moreover, these membranes demonstrate a high water flux exceeding 291.8 L m^-2h⁻¹ bar⁻¹ and exceptional long-term operational stability lasting at least 2880 min. The superior performance of COF membranes is attributed to their optimal pore size, excellent hydrophilicity, and high crystallinity. This finding offers a promising approach for effectively eliminating water-soluble organic pollutants, thereby ensuring the safety and sustainability of the water supply.

各种痕量水溶性有机污染物（如染料）的存在对人类健康和生态系统构成了巨大的潜在风险。膜技术为从水环境中去除这些污染物提供了一种前景广阔的可持续方法。然而，大多数商用膜的无定形结构使其难以实现高水通量的有效分离。在此，我们首次提出了一系列具有不同烷氧基侧链长度的新型亲水性 COF 膜。这些烷氧基侧链功能 COF 膜能有效阻隔水溶性有机染料，包括玫瑰红（50%）、刚果红（98%）、艳蓝 R250（99%）和阿尔金山蓝（99%）。此外，这些膜还具有超过 291.8 L m-2h-1 bar-1 的高水通量和至少 2880 分钟的长期运行稳定性。COF 膜的卓越性能归功于其最佳的孔径、出色的亲水性和高结晶度。这一发现为有效消除水溶性有机污染物提供了一种可行的方法，从而确保了供水的安全性和可持续性。

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引用次数: 0

Effective elimination of multiple heavy metal ions from wastewater using circular liquid-liquid extraction based on trioctylammonium carboxylate ionic liquids 利用基于三辛基铵羧酸盐离子液体的循环液液萃取技术有效去除废水中的多种重金属离子

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-26 DOI: 10.1016/j.seppur.2024.129880

The widespread discharge of effluents containing heavy metal ions (HMIs) from various industries into natural water bodies has become an alarming concern due to their harmful effects. Recently, ionic liquid (IL)-assisted liquid–liquid extraction (LLE) has emerged as a rapid and facile method for treating industrial effluents, effectively reducing the risk of secondary pollution. The primary objective of this study was to design novel hydrophobic ILs for the extractive removal of toxic HMIs from aqueous media. These hydrophobic ILs were designed by incorporating cyclic carboxylic acids (thiobenzoic acid, pyridine dicarboxylic acid, and pyrimidine dicarboxylic acid) with trioctylamine. The aim was to evaluate the effect of different coordinating atoms in the cyclic carboxylic acids on HMI extraction, while the trioctylamine moiety was chosen to provide the necessary hydrophobicity. The synthesized ILs were evaluated for their efficiency in the extractive removal of toxic HMIs, including Cu(II), Cd(II), Ni(II), and Pb(II), both individually and from their mixtures, under simulated industrial conditions. Thorough optimization was performed to identify the key parameters affecting extraction efficiency. The HMI concentrations were adjusted to their reported maximum contamination limits to ensure real-time applicability, and the ILs demonstrated successful extraction under these conditions. Experimental studies showed that the ILs were able to effectively remove HMIs even from mixtures, confirming their practical relevance. A detailed comparison with literature data revealed that the extraction mechanism primarily relied on the preferential coordination of metals, following the HSAB principle. Furthermore, metal ions were stripped back using disodium EDTA solution, facilitating the regeneration of the ILs for multiple reuse cycles and supporting a sustainable, circular process.

由于重金属离子（HMIs）的有害影响，各行各业普遍向自然水体排放含有重金属离子（HMIs）的污水，这已成为一个令人担忧的问题。最近，离子液体（IL）辅助液液萃取（LLE）已成为一种快速、简便的处理工业废水的方法，可有效降低二次污染的风险。本研究的主要目的是设计新型疏水性离子液体，用于从水介质中萃取去除有毒的 HMIs。通过将环状羧酸（硫代苯甲酸、吡啶二羧酸和嘧啶二羧酸）与三辛胺结合，设计出了这些疏水型 IL。目的是评估环状羧酸中不同配位原子对 HMI 提取的影响，而选择三辛胺则是为了提供必要的疏水性。在模拟工业条件下，评估了合成的 ILs 在单独萃取和从混合物中萃取去除有毒 HMIs（包括 Cu(II)、Cd(II)、Ni(II)和 Pb(II)）方面的效率。为确定影响萃取效率的关键参数，进行了彻底的优化。为了确保实时适用性，将 HMI 浓度调整到了其报告的最大污染限值，在这些条件下，ILs 成功地实现了萃取。实验研究表明，即使在混合物中，ILs 也能有效地去除 HMIs，这证实了它们的实用性。与文献数据的详细对比显示，萃取机理主要依赖于金属的优先配位，遵循了 HSAB 原理。此外，使用乙二胺四乙酸二钠溶液可将金属离子剥离出来，从而促进了惰性离子的再生，实现了多次重复利用，支持了可持续的循环工艺。

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引用次数: 0

Highly selective alginate/CuO mixed matrix membranes for efficient dehydration pervaporation of various organic solvents 用于各种有机溶剂高效脱水渗透的高选择性藻酸盐/氧化铜混合基质膜

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-25 DOI: 10.1016/j.seppur.2024.129865

Pervaporation is an energy-efficient technique for dehydrating organic solvents from aqueous mixtures. To develop a highly selective pervaporation membrane with broad usage, we incorporated three types of CuO particles (solid CuO-S, sea urchin-like CuO-U, and porous CuO-P) into sodium alginate (Alg) for fabricating the Alg/CuO mixed matrix membranes (MMMs). The CuO syntheses and membrane preparation are simple and eco-friendly. The synthesized particles and membranes were systematically characterized. The improved hydrophilic feature of Alg/CuO MMMs was validated from the reduced water contact angle and higher water swelling ratio with increasing CuO wt%. When the Alg/CuO MMMs were applied to the pervaporation of 30 wt% water/isopropanol (IPA) at 25 ℃, both the permeation flux and separation factor were enhanced significantly compared to the pure Alg membrane. The separation efficiency followed the order of Alg/CuO-S MMMs < Alg/CuO-U MMMs < Alg/CuO-P MMMs, in good agreement with their water swelling tendency. The incorporation of 3 wt% porous CuO-P particles in MMM achieved the optimal dehydration efficacy (normalized total flux of 3.5 kg m^-2h⁻¹, separation factor of ca. 5000, and water purity of 99.96 wt%, with a stable performance over 168 h). A further larger loading wt% led to a decreased separation selectivity due to more void formation from particle aggregation. With an increase in feed temperature, both the permeation flux and separation factor were improved; however, the increase in feed water concentration deteriorated the separation selectivity while enhancing the flux. Furthermore, the high selectivity and broad applicability of Alg/3% CuO-P MMM were fruitfully demonstrated by exhibiting superior separation efficiencies in dehydrating various polar aprotic solvents compared with several membranes discussed in the literature.

渗透蒸发是从水性混合物中脱水有机溶剂的一种节能技术。为了开发具有广泛用途的高选择性渗透蒸发膜，我们在海藻酸钠（Alg）中加入了三种类型的 CuO 粒子（固态 CuO-S、海胆状 CuO-U 和多孔 CuO-P），以制造 Alg/CuO 混合基质膜（MMMs）。CuO 的合成和膜的制备简单且环保。对合成的颗粒和膜进行了系统表征。随着 CuO wt% 的增加，Alg/CuO 混合基质膜的水接触角减小，水膨胀率升高，验证了其亲水特性的改善。将 Alg/CuO MMMs 应用于 25 ℃ 下 30 wt% 水/异丙醇（IPA）的渗透蒸发，与纯 Alg 膜相比，渗透通量和分离因子均显著提高。分离效率依次为 Alg/CuO-S MMMs < Alg/CuO-U MMMs < Alg/CuO-P MMMs，这与它们的水溶胀倾向非常吻合。在 MMM 中加入 3 wt%的多孔 CuO-P 颗粒可获得最佳脱水效果（归一化总通量为 3.5 kg m-2h-1，分离因子约为 5000，水纯度为 99.96 wt%，且在 168 小时内性能稳定）。由于颗粒聚集形成了更多的空隙，装载量 wt% 越大，分离选择性越低。随着进料温度的升高，渗透通量和分离因子都得到了改善；然而，进料水浓度的增加在提高通量的同时，却降低了分离选择性。此外，与文献中讨论的几种膜相比，Alg/3% CuO-P MMM 在脱水各种极性烷基溶剂时表现出更高的分离效率，从而证明了它的高选择性和广泛适用性。

{"title":"Highly selective alginate/CuO mixed matrix membranes for efficient dehydration pervaporation of various organic solvents","authors":"","doi":"10.1016/j.seppur.2024.129865","DOIUrl":"10.1016/j.seppur.2024.129865","url":null,"abstract":"<div><div>Pervaporation is an energy-efficient technique for dehydrating organic solvents from aqueous mixtures. To develop a highly selective pervaporation membrane with broad usage, we incorporated three types of CuO particles (solid CuO-S, sea urchin-like CuO-U, and porous CuO-P) into sodium alginate (Alg) for fabricating the Alg/CuO mixed matrix membranes (MMMs). The CuO syntheses and membrane preparation are simple and eco-friendly. The synthesized particles and membranes were systematically characterized. The improved hydrophilic feature of Alg/CuO MMMs was validated from the reduced water contact angle and higher water swelling ratio with increasing CuO wt%. When the Alg/CuO MMMs were applied to the pervaporation of 30 wt% water/isopropanol (IPA) at 25 ℃, both the permeation flux and separation factor were enhanced significantly compared to the pure Alg membrane. The separation efficiency followed the order of Alg/CuO-S MMMs < Alg/CuO-U MMMs < Alg/CuO-P MMMs, in good agreement with their water swelling tendency. The incorporation of 3 wt% porous CuO-P particles in MMM achieved the optimal dehydration efficacy (normalized total flux of 3.5 kg m<sup>-2</sup>h<sup>−1</sup>, separation factor of ca. 5000, and water purity of 99.96 wt%, with a stable performance over 168 h). A further larger loading wt% led to a decreased separation selectivity due to more void formation from particle aggregation. With an increase in feed temperature, both the permeation flux and separation factor were improved; however, the increase in feed water concentration deteriorated the separation selectivity while enhancing the flux. Furthermore, the high selectivity and broad applicability of Alg/3% CuO-P MMM were fruitfully demonstrated by exhibiting superior separation efficiencies in dehydrating various polar aprotic solvents compared with several membranes discussed in the literature.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327386","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}

引用次数: 0

Vinyl-functionalized covalent organic framework via tuning π-conjugation effectively promotes photocatalytic hydrogen evolution 通过调整π-共轭实现乙烯基官能化共价有机框架，有效促进光催化氢气进化

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-25 DOI: 10.1016/j.seppur.2024.129809

Covalent organic frameworks (COFs) show great potential in photocatalytic water splitting. However, it is still crucial to explore the effect of π-conjugation of COFs on photocatalytic performance. Here, a series of COFs with different degrees of conjugation (DHTA-BD COF, DHTA-STP COF, DHTA-AZO COF) have been investigated through the synergistic effect of varying the planarity and π electronic structures. The results show that the vinyl-functionalized DHTA-STP COF achieves an excellent photocatalytic hydrogen generation rate of 16.1 mmol g¹h⁻¹ under visible light conditions, 4.3 times higher than the DHTA-BD COF, and the hydrogen production of the DHTA-AZO COF is extremely low under the same test conditions. Moreover, the synergistic effect of the smaller dihedral angle and ordered π electronic structures with the introduction of vinyl structure in DHTA-STP COF leads to a higher degree of conjugation, facilitating π delocalization efficiency and promoting the redistribution of charges. Experimental and theoretical calculations have demonstrated that DHTA-STP COF is a promising photoactive semiconductor with the strongest photocurrent, the smallest impedance, the narrowest electronic bandgap, and the strongest separation ability of electron-hole pairs. This finding provides guidance for introducing appropriate conjugated units into COFs to improve the photocatalytic hydrogen production efficiency.

共价有机框架（COFs）在光催化水分离方面显示出巨大的潜力。然而，探索 COF 的 π 共轭对光催化性能的影响仍然至关重要。本文通过改变平面度和π电子结构的协同效应，研究了一系列不同共轭度的 COFs（DHTA-BD COF、DHTA-STP COF、DHTA-AZO COF）。结果表明，乙烯基官能化的 DHTA-STP COF 在可见光条件下实现了 16.1 mmol g1h-1 的优异光催化产氢率，是 DHTA-BD COF 的 4.3 倍，而 DHTA-AZO COF 在相同测试条件下的产氢率极低。此外，DHTA-STP COF 中较小的二面角和有序的 π 电子结构与乙烯基结构的引入的协同效应导致了较高的共轭度，有利于提高 π 脱ocal 化效率，促进电荷的再分布。实验和理论计算证明，DHTA-STP COF 是一种前景广阔的光活性半导体，具有最强的光电流、最小的阻抗、最窄的电子带隙和最强的电子-空穴对分离能力。这一发现为在 COF 中引入适当的共轭单元以提高光催化制氢效率提供了指导。

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引用次数: 0

Eco-friendly bionic superwetting Janus membranes prepared from paper-based laser-induced graphene for photothermal anti-icing and on-demand oil–water separation 利用纸基激光诱导石墨烯制备环保型仿生超润湿 Janus 膜，用于光热防冰和按需油水分离

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-25 DOI: 10.1016/j.seppur.2024.129859

Laser-induced graphene (LIG) from carbon precursors is used in the manufacture of semiconductors, energy and biomedical devices. To expand its field of applications, there is a strong need to explore LIG conversion of eco-friendly precursors. An approach combining bionic structures and surface modification on paper-based LIG was investigated for producing asymmetric superwetting Janus membranes. Molecular dynamic simulation illustrates the paper-based LIG conversion mechanism. The Octadecanethiol-modified bionic crescent-shaped LIG surface exhibited superhydrophobic performance, the water contact angle (WCA) is 157° and the water sliding angle (WSA) is 3.5°. The plasma-modified LIG surface was superhydrophilic with the WCA of 0°. The Janus membranes were demonstrated for high-efficient separation of light oil–water and heavy oil–water mixtures. Furthermore, the superhydrophobic surface of the Janus membranes with excellent photothermal properties exhibited superior anti-icing capability. The proposed approach for fabrication of bionic Janus membranes would provide an eco-friendly solution to LIG applications.

碳前驱体激光诱导石墨烯（LIG）可用于制造半导体、能源和生物医学设备。为了扩大其应用领域，亟需探索将生态友好型前驱体转化为石墨烯。本文研究了一种结合纸基 LIG 的仿生结构和表面改性的方法，用于生产非对称超润湿 Janus 膜。分子动力学模拟说明了纸基 LIG 的转化机制。十八硫醇改性的仿生新月形 LIG 表面具有超疏水性能，水接触角 (WCA) 为 157°，水滑动角 (WSA) 为 3.5°。等离子体改性的 LIG 表面具有超亲水性，WCA 为 0°。实验证明，Janus 膜能高效分离轻油-水和重油-水混合物。此外，Janus 膜的超疏水表面具有优异的光热性能，表现出卓越的抗结冰能力。所提出的仿生 Janus 膜制造方法将为 LIG 应用提供一种生态友好型解决方案。

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引用次数: 0

Structural and functional design of CTAB-geopolymer adsorbents for rapid removal of tetracycline: A comparative study 用于快速去除四环素的 CTAB-土工聚合物吸附剂的结构和功能设计：比较研究

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-25 DOI: 10.1016/j.seppur.2024.129872

A powder, inorganic membrane and 3D printing cetyltrimethylammonium bromide (CTAB)-geopolymer adsorbents system for adsorbing tetracycline (TC) was developed. And the adsorption properties, adsorption mechanism, adsorption cycle application based on the dynamic pH of adsorption system were systematically investigated by experiment, characterization and density functional theory (DFT) calculation. The introduction of CTAB significantly increased the adsorption response to TC in the high alkaline environment caused by spontaneous alkali release of geopolymer. The adsorption of CTAB-geopolymer for TC was most efficient in the dynamic pH range corresponding to TC^- species. The predominant influencing mechanism between CTAB-geopolymer with TC was electrostatic interaction assisted by the hydrogen bonding and n-π interaction. The powder adsorbent with 11 wt% CTAB can capture 92.38 % TC at 2 min and fitted the pseudo-second-order model, and was also suitable for adsorption of trace TC. Although the extension of the diffusion path of the monolithic adsorbents limited the adsorption rate, the 3D printed adsorbent showed an adsorption efficiency of 84.20 % at 302 min. The outstanding adsorption (4 times)-desorption (3 times) cycle properties of 11 %CT-GA (81.15 % at 24 min, 4th adsorption) and cycle cumulative adsorption efficiency of 11 %CT-3DP (59.23 % at 120 min, 4th adsorption) adsorbent were exhibited. Furthermore, a high accuracy performance prediction model with the mean R² value tended to 1 and the low root mean square error (0.0747) was provided, which can provide theoretical and technical reference for the subsequent industrial application of CTAB-geopolymer adsorbents.

开发了一种粉末、无机膜和3D打印十六烷基三甲基溴化铵（CTAB）-土工聚合物吸附剂系统，用于吸附四环素（TC）。通过实验、表征和密度泛函理论（DFT）计算，系统研究了基于吸附体系动态 pH 值的吸附性能、吸附机理和吸附循环应用。结果表明：在高碱性环境中，由于土工聚合物自发释碱，CTAB的引入明显提高了对TC的吸附响应。在与 TC 物种相对应的动态 pH 值范围内，CTAB-土工聚合物对 TC 的吸附效率最高。CTAB-土工聚合物与 TC 的主要影响机制是静电作用，辅以氢键和 n-π 作用。含有 11 wt% CTAB 的粉末吸附剂在 2 min 时可捕获 92.38 % 的 TC，符合伪二阶模型，也适用于痕量 TC 的吸附。虽然整体吸附剂扩散路径的延长限制了吸附速率，但三维打印吸附剂在 302 分钟时的吸附效率达到 84.20%。11 %CT-GA 的吸附（4 次）-解吸（3 次）循环性能（24 分钟时为 81.15%，第 4 次吸附）和 11 %CT-3DP 的循环累积吸附效率（120 分钟时为 59.23%，第 4 次吸附）均表现突出。此外，还提供了一个平均 R2 值趋于 1 且均方根误差（0.0747）较低的高精度性能预测模型，可为 CTAB-土工聚合物吸附剂的后续工业应用提供理论和技术参考。

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引用次数: 0

Defluoridation of spent cathode carbon using molten salt assisted roasting 利用熔盐辅助焙烧对废阴极碳进行脱氟处理

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-25 DOI: 10.1016/j.seppur.2024.129885

Spent cathode carbon (SCC), generated during production of aluminum electrolysis was classified as hazardous solid waste for contain fluoride and cyanide. The harmless treatment is great significance in reducing environmental pollution and resource recovery. This study investigated the optimal process parameters and action mechanism for Na₂CO₃ and Na₂SiO₃ assisted roasting SCC. Under optimal conditions, C and F content of roasting solid products by Na₂CO₃ and Na₂SiO₃ were 95.78 wt%, 1.4 wt% and 86.57 wt%, 1.27 wt%, respectively. Na₂CO₃ reacts with CaF₂ and Na₃AlF₆ inside the pores by infiltration to form NaF and generate thermal stresses to reduce median particle size of SCC from 5.98 μm (conventional roasting) to 4.56 μm and promoting fluoride removal. Na₂SiO₃ could effectively remove Na₃AlF₆ and adheres to surface of carbon as spherical particles. The results provide a reference basis for efficient defluoridation and fixed carbon high-value recycling, which consistent with green and sustainable development concept.

电解铝生产过程中产生的废阴极炭（SCC）因含有氟化物和氰化物而被列为危险固体废物。无害化处理对减少环境污染和资源回收具有重要意义。本研究探讨了 Na2CO3 和 Na2SiO3 辅助焙烧 SCC 的最佳工艺参数和作用机理。在最佳条件下，Na2CO3和Na2SiO3焙烧固体产物的C和F含量分别为95.78 wt%、1.4 wt%和86.57 wt%、1.27 wt%。Na2CO3 与孔隙内的 CaF2 和 Na3AlF6 通过渗透反应生成 NaF，并产生热应力，使 SCC 的中值粒径从 5.98 μm（传统焙烧）减小到 4.56 μm，从而促进氟的去除。Na2SiO3 能有效去除 Na3AlF6，并以球形颗粒附着在碳表面。研究结果为高效脱氟及固定碳高值化回收利用提供了参考依据，符合绿色可持续发展理念。

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引用次数: 0

Study on the gas dissolution performance and bubble generation characteristics of a jet flow type pressurized tubular microbubble generator 喷流式加压管状微气泡发生器的气体溶解性能和气泡生成特性研究

IF 8.1 1区工程技术 Q1 ENGINEERING, CHEMICAL

Separation and Purification Technology

Pub Date : 2024-09-25 DOI: 10.1016/j.seppur.2024.129886

Microbubble generation technology has the potential to significantly enhance the separation efficiency of offshore oilfield produced water flotation treatment devices, which currently display unstable performance. In this study, we developed a jet flow type pressurized tubular microbubble generator, comprising a jet-dissolved gas tube (JDGT) and a standard ball valve. The JDGT was designed based on the principle of intensifying bubble breakup through jet nozzles and enhancing gas dissolution via up-down circulation vortex. We proposed an innovative Computational Fluid Dynamics (CFD) model that utilizes User Defined Functions (UDF) to predict the flow pattern and dissolved oxygen (DO) distribution within the tube. The relative error between numerical simulations and experimental results was 5.25 %. Under identical operating conditions, the JDGT can efficiently produce gas-dissolved water in 3.5 s, achieving a dissolved gas efficiency of 80.24 %, compared to 58.31 % for a conventional jet vertical vessel with a hydraulic retention time of 30 s. High-quality microbubbles can be generated through decompression via a standard ball valve. The oxygen volumetric mass transfer coefficient increases with the inlet water flow rate, the gas–liquid volume ratio, and increased dissolved pressure. As the inlet water flow rate increases, the Sauter mean bubble diameter initially increases before decreasing. Both the gas–liquid volume ratio and dissolved gas pressure are exponentially related to the Sauter mean bubble diameter. An engineering prototype with a treatment capacity of 35 m³/h was successfully field-tested on a platform in the South China Sea. The test results indicated that when the microbubble generator was connected to a vertical air flotation unit with a 10 % reflux flow system, the average oil concentration at the unit’s outlet was 13 mg/L. The calculated average oil removal efficiency was 72.38 %, which is 12.8 % higher than that achieved without a tubular microbubble generator.

目前，海上油田采出水气浮处理装置的性能不稳定，而微气泡生成技术有望显著提高其分离效率。在这项研究中，我们开发了一种射流式加压管状微气泡发生器，由一个射流溶解气体管（JDGT）和一个标准球阀组成。JDGT 的设计原理是通过射流喷嘴强化气泡破裂，并通过上下循环涡流加强气体溶解。我们提出了一种创新的计算流体动力学（CFD）模型，利用用户定义函数（UDF）来预测管内的流动模式和溶解氧（DO）分布。数值模拟与实验结果之间的相对误差为 5.25%。在相同的操作条件下，JDGT 可以在 3.5 秒内高效地产生气溶水，溶气效率达到 80.24%，而水力停留时间为 30 秒的传统垂直喷射容器的溶气效率为 58.31%。氧气体积传质系数随进水流速、气液体积比和溶解压力的增加而增加。随着进水流量的增加，萨特平均气泡直径最初会增大，然后减小。气液体积比和溶解气体压力与萨特平均气泡直径呈指数关系。处理能力为 35 立方米/小时的工程原型在南海的一个平台上成功进行了现场测试。试验结果表明，当微气泡发生器连接到带有 10% 回流流量系统的垂直气浮装置时，装置出口处的平均油类浓度为 13 mg/L。计算得出的平均除油效率为 72.38%，比不使用管式微气泡发生器时的除油效率高 12.8%。

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