Pub Date : 2024-09-21DOI: 10.1016/j.seppur.2024.129754
Currently, most commercial membranes are used at temperatures below 50 °C. For high temperature water treatment, nanofiltration membranes with good thermal stability are highly sought after. In order to construct a novel polyamide thin-film composite nanofiltration (TFC NF) membrane, Congo red (CR) as monomer was introduced to the aqueous phase and the chemical structure of the selective layer was changed. Next, a thorough investigation was conducted into the impacts of the piperazine (PIP) to CR ratio on the surface morphology, separation efficiency and chemical structure of the membranes. The TFC NF membrane prepared after parameter optimization exhibited high retention (Na2SO4, >98 %) and flux up to 30 L·m−2·h−1·bar−1 at room temperature. Moreover, the Na2SO4 retention of the TFC NF membrane decreased by less than 1 % when used at 90 °C, demonstrating excellent heat resistance. Meanwhile, the incorporation of CR allowed the structure of the TFC NF membranes to be altered under UV irradiation conditions, which provided new insights into the optical modulation of the composite membrane properties. A promising and reproducible methodology for the development of high flux TFC NF membrane with thermal stability was offered, achieving a breakthrough in water treatment technology under high-temperature conditions.
{"title":"Photosensitive and high temperature resistant polyamide composite nanofiltration membranes with high flux and stable retention","authors":"","doi":"10.1016/j.seppur.2024.129754","DOIUrl":"10.1016/j.seppur.2024.129754","url":null,"abstract":"<div><div>Currently, most commercial membranes are used at temperatures below 50 °C. For high temperature water treatment, nanofiltration membranes with good thermal stability are highly sought after. In order to construct a novel polyamide thin-film composite nanofiltration (TFC NF) membrane, Congo red (CR) as monomer was introduced to the aqueous phase and the chemical structure of the selective layer was changed. Next, a thorough investigation was conducted into the impacts of the piperazine (PIP) to CR ratio on the surface morphology, separation efficiency and chemical structure of the membranes. The TFC NF membrane prepared after parameter optimization exhibited high retention (Na<sub>2</sub>SO<sub>4</sub>, >98 %) and flux up to 30 L·m<sup>−2</sup>·h<sup>−1</sup>·bar<sup>−1</sup> at room temperature. Moreover, the Na<sub>2</sub>SO<sub>4</sub> retention of the TFC NF membrane decreased by less than 1 % when used at 90 °C, demonstrating excellent heat resistance. Meanwhile, the incorporation of CR allowed the structure of the TFC NF membranes to be altered under UV irradiation conditions, which provided new insights into the optical modulation of the composite membrane properties. A promising and reproducible methodology for the development of high flux TFC NF membrane with thermal stability was offered, achieving a breakthrough in water treatment technology under high-temperature conditions.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327460","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129827
Tetrabromobisphenol A epoxy resin (TBBPAER) is the main non-metallic component of electronic waste. The scale of electronic waste production and the accompanying TBBPAER waste disposal problems represent a great opportunity for chemical upcycling. But the chemical upcycling of TBBPAER faces great challenges due to its high bromine content and thermally stability. In this study, a subcritical water ammonia (SWA) process combined with waste copper-based catalyst (WCC) selectively converted TBBPAER in high yields (63.46 % at 300°C for 15 min and 73.66 % for 60 min) to low molecular-weight liquid products including high value-added methyl pyrimidine and phenols. The electron transfer among multivalent copper species contained in the WCC promoted the production of free radicals OH, O2−, NH2, and :NH, which resulted in the efficient conversion of TBBPAER and a 99.29 % of debromination ratio. The molecular chain of TBBPAER was snipped by OH and NH2 to produce tetrabromobisphenol A groups (TAG) and ternary carbon groups (TCG). The further degradation of TAG resulted in the producing of phenol chemicals with a purity of 91.8 % (GC peak area%). The further cyclization of TCG induced by :NH produced methyl pyrimidine with a purity of 91.9 % (GC peak area%). The formation of copper ammonia complex led to the leaching/recovery of 86.6 % of copper from the WCC. The SWA-WCC approach demonstrated how TBBPAER waste could be a viable feedstock for the producing of high value-added methyl pyrimidine and phenol chemicals. This study provided a novel sustainable strategy for synchronous treatment/upcycling of the two different wastes of TBBPAER and WCC. The leaching toxicity test of Cu and Zn for the solid residue after the co-treatment showed that their leaching concentrations were much lower than the hazardous waste standard.
{"title":"Selective upcycling of brominated epoxy resin by subcritical water ammonia process with waste copper-based catalyst: Production of high purity methyl pyrimidine/phenols and copper recovery","authors":"","doi":"10.1016/j.seppur.2024.129827","DOIUrl":"10.1016/j.seppur.2024.129827","url":null,"abstract":"<div><div>Tetrabromobisphenol A epoxy resin (TBBPAER) is the main non-metallic component of electronic waste. The scale of electronic waste production and the accompanying TBBPAER waste disposal problems represent a great opportunity for chemical upcycling. But the chemical upcycling of TBBPAER faces great challenges due to its high bromine content and thermally stability. In this study, a subcritical water ammonia (SWA) process combined with waste copper-based catalyst (WCC) selectively converted TBBPAER in high yields (63.46 % at 300°C for 15 min and 73.66 % for 60 min) to low molecular-weight liquid products including high value-added methyl pyrimidine and phenols. The electron transfer among multivalent copper species contained in the WCC promoted the production of free radicals <img>OH, <img>O<sub>2</sub><sup>−</sup>, <img>NH<sub>2</sub>, and :NH, which resulted in the efficient conversion of TBBPAER and a 99.29 % of debromination ratio. The molecular chain of TBBPAER was snipped by <img>OH and <img>NH<sub>2</sub> to produce tetrabromobisphenol A groups (TAG) and ternary carbon groups (TCG). The further degradation of TAG resulted in the producing of phenol chemicals with a purity of 91.8 % (GC peak area%). The further cyclization of TCG induced by :NH produced methyl pyrimidine with a purity of 91.9 % (GC peak area%). The formation of copper ammonia complex led to the leaching/recovery of 86.6 % of copper from the WCC. The SWA-WCC approach demonstrated how TBBPAER waste could be a viable feedstock for the producing of high value-added methyl pyrimidine and phenol chemicals. This study provided a novel sustainable strategy for synchronous treatment/upcycling of the two different wastes of TBBPAER and WCC. The leaching toxicity test of Cu and Zn for the solid residue after the co-treatment showed that their leaching concentrations were much lower than the hazardous waste standard.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327602","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129829
With the ongoing development of human society and technological advancements, the widespread discharge and utilization of pollutants such as antibiotics, resistance genes, and pathogens present a significant threat to human health. Advanced oxidation technology based on persulfate (PS) is widely used in pollutant treatment. Photoactivation has the advantages of safety, economy, and high efficiency; therefore, it has been applied in water treatment research. However, there have been no reports summarizing how the active species are produced during PS activation. This study elucidated the activation mechanism of the photoactivated PS from two aspects: photoexcitation and photocatalysis. Subsequently, the current research and applications of photoactivated PS to remove pollutants are discussed, important reactive oxygen species (ROS) in this technology are summarized, and the production path and reaction mechanism of ROS are further analyzed and summarized. Finally, it is proposed that the catalyst is the key to photoactivated PS, and the method and mechanism of catalyst modification are discussed to provide theoretical support for improving the efficiency of photoactivated PS technology. This study is helpful for further understanding the mechanism and key factors of photoactivated PS removal from pollutants and provides better prospects for future research.
{"title":"Photoactivated persulfate for water and wastewater remediations: Mechanisms, applications, and catalysts","authors":"","doi":"10.1016/j.seppur.2024.129829","DOIUrl":"10.1016/j.seppur.2024.129829","url":null,"abstract":"<div><div>With the ongoing development of human society and technological advancements, the widespread discharge and utilization of pollutants such as antibiotics, resistance genes, and pathogens present a significant threat to human health. Advanced oxidation technology based on persulfate (PS) is widely used in pollutant treatment. Photoactivation has the advantages of safety, economy, and high efficiency; therefore, it has been applied in water treatment research. However, there have been no reports summarizing how the active species are produced during PS activation. This study elucidated the activation mechanism of the photoactivated PS from two aspects: photoexcitation and photocatalysis. Subsequently, the current research and applications of photoactivated PS to remove pollutants are discussed, important reactive oxygen species (ROS) in this technology are summarized, and the production path and reaction mechanism of ROS are further analyzed and summarized. Finally, it is proposed that the catalyst is the key to photoactivated PS, and the method and mechanism of catalyst modification are discussed to provide theoretical support for improving the efficiency of photoactivated PS technology. This study is helpful for further understanding the mechanism and key factors of photoactivated PS removal from pollutants and provides better prospects for future research.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327388","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129742
Great attention has been paid to effectively capture trace CO2 in air or a confined space for ensuring human safety, but it remains challenging to enhance CO2 capacity and selectivity concurrently. In this study, metal–organic frameworks (MOFs) were combined with amino groups (NH2-MIL-125(Ti) and NH2-UIO-66(Zr)) and amino acid anion-functionalized ionic liquids (ILs), namely 1-Butyl-3-methylimidazolium glycinate ([BMIm]Gly) and 1-Butyl-3-methylimidazolium arginine ([BMIm]Arg) to prepare various ionic liquid (IL) composites containing various IL contents. Relative to pristine supports, incorporating ILs significantly enhanced CO2 capacity together with CO2/N2 selectivity, in particular in the confined spaces (<5000 ppm) or in air (415 ppm). At a 50 wt% IL loading, new ultra-micropores (<0.65 nm) could be obtained in IL-NH2-UIO-66(Zr) composite, but they did not occur within pristine supports or the rest IL-NH2-UIO-66(Zr) (10 wt%, 30 wt% and 70 wt%). Among them, CO2 uptake of 50 wt% [BMIm]Arg-NH2-UIO-66(Zr) peak at 0.0005 and 0.005 bar (2.93 and 3.87 mmolCO2/g-adsorbent, respectively) at 313 K; besides, recyclability significantly increased compared with the latest values reported. Additionally, the excellent optimal CO2/N2 selectivity was determined to be 8916 at 0.005 bar and 288 K, which increased by 254.7 folds relative to NH2-UIO-66(Zr). In the meantime, as revealed by mixed gas breakthrough experimental results, 50 wt% [BMIm]Arg-NH2-UIO-66(Zr) showed superb CO2 separation effect in air and simulated confined spaces. Such ultra-high CO2 separation efficacy is associated with the synergistic effect of chemical interaction of IL anion with amino groups in MOFs and CO2 and the novel ultra-micropore effect. Findings in the present work shed more lights on designing hierarchically porous IL composites that possess ultra-micropores to efficiently remove trace CO2.
为确保人类安全，有效捕获空气或密闭空间中的痕量二氧化碳已受到极大关注，但同时提高二氧化碳的容量和选择性仍具有挑战性。本研究将金属有机框架（MOFs）与氨基（NH2-MIL-125(Ti) 和 NH2-UIO-66(Zr)）和氨基酸阴离子官能化离子液体（ILs）（即 1-丁基-3-甲基咪唑鎓甘氨酸盐（[BMIm]Gly）和 1-丁基-3-甲基咪唑鎓精氨酸盐（[BMIm]Arg））相结合，制备了含有不同 IL 含量的各种离子液体（IL）复合材料。与原始支撑物相比，IL 的加入显著提高了 CO2 容量和 CO2/N2 选择性，尤其是在密闭空间（<5000 ppm）或空气（415 ppm）中。当 IL 含量为 50 wt%时，IL-NH2-UIO-66(Zr)复合材料中会出现新的超微孔（<0.65 nm），但在原始支撑物或其余 IL-NH2-UIO-66(Zr) （10 wt%、30 wt% 和 70 wt%）中则不会出现。其中，50 wt%[BMIm]Arg-NH2-UIO-66(Zr)在 313 K 时的二氧化碳吸收峰值为 0.0005 和 0.005 bar（分别为 2.93 和 3.87 mmolCO2/g-吸附剂）；此外，与最新报道的数值相比，可回收性显著提高。此外，在 0.005 巴和 288 K 条件下，最佳 CO2/N2 选择性为 8916，比 NH2-UIO-66(Zr)提高了 254.7 倍。同时，混合气体突破实验结果表明，50 wt% [BMIm]Arg-NH2-UIO-66(Zr) 在空气和模拟密闭空间中表现出卓越的二氧化碳分离效果。这种超高的二氧化碳分离效果与 IL 阴离子与 MOFs 中氨基的化学作用和二氧化碳的协同效应以及新型超微孔效应有关。本研究的发现为设计具有超微孔的分层多孔 IL 复合材料以高效去除痕量 CO2 提供了更多启示。
{"title":"Selective adsorption of trace CO2 by immobilized amino acid ionic liquids with ultra-micropores based on amino MOFs","authors":"","doi":"10.1016/j.seppur.2024.129742","DOIUrl":"10.1016/j.seppur.2024.129742","url":null,"abstract":"<div><div>Great attention has been paid to effectively capture trace CO<sub>2</sub> in air or a confined space for ensuring human safety, but it remains challenging to enhance CO<sub>2</sub> capacity and selectivity concurrently. In this study, metal–organic frameworks (MOFs) were combined with amino groups (NH<sub>2</sub>-MIL-125(Ti) and NH<sub>2</sub>-UIO-66(Zr)) and amino acid anion-functionalized ionic liquids (ILs), namely 1-Butyl-3-methylimidazolium glycinate ([BMIm]Gly) and 1-Butyl-3-methylimidazolium arginine ([BMIm]Arg) to prepare various ionic liquid (IL) composites containing various IL contents. Relative to pristine supports, incorporating ILs significantly enhanced CO<sub>2</sub> capacity together with CO<sub>2</sub>/N<sub>2</sub> selectivity, in particular in the confined spaces (<5000 ppm) or in air (415 ppm). At a 50 wt% IL loading, new ultra-micropores (<0.65 nm) could be obtained in IL-NH<sub>2</sub>-UIO-66(Zr) composite, but they did not occur within pristine supports or the rest IL-NH<sub>2</sub>-UIO-66(Zr) (10 wt%, 30 wt% and 70 wt%). Among them, CO<sub>2</sub> uptake of 50 wt% [BMIm]Arg-NH<sub>2</sub>-UIO-66(Zr) peak at 0.0005 and 0.005 bar (2.93 and 3.87 mmolCO<sub>2</sub>/g-adsorbent, respectively) at 313 K; besides, recyclability significantly increased compared with the latest values reported. Additionally, the excellent optimal CO<sub>2</sub>/N<sub>2</sub> selectivity was determined to be 8916 at 0.005 bar and 288 K, which increased by 254.7 folds relative to NH<sub>2</sub>-UIO-66(Zr). In the meantime, as revealed by mixed gas breakthrough experimental results, 50 wt% [BMIm]Arg-NH<sub>2</sub>-UIO-66(Zr) showed superb CO<sub>2</sub> separation effect in air and simulated confined spaces. Such ultra-high CO<sub>2</sub> separation efficacy is associated with the synergistic effect of chemical interaction of IL anion with amino groups in MOFs and CO<sub>2</sub> and the novel ultra-micropore effect. Findings in the present work shed more lights on designing hierarchically porous IL composites that possess ultra-micropores to efficiently remove trace CO<sub>2</sub>.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320329","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129822
Lately, Ca-based sorbents with a core–shell structure have been effectively produced to augment the sorbent’s capabilities. However, modifying the pristine core of Ca-based pellets with a core–shell structure notably influences the performance of the synthesized sorbent, and research in this domain remains scarce. Here, two categories of Al-stabilized, Ca-based pristine cores were produced using Ca(OH)2 mixed with Al-based stabilizer precursors of insoluble aluminum oxide and soluble aluminum nitrate, respectively, through the extrusion-spheronization technique. Due to the impact of mechanical extrusion, soluble aluminum nitrate can accumulate in-homogeneously in the Ca-based pristine core, leading to its expansion and rupture during the high-temperature calcination stage because of the decomposition of aluminum nitrate. The oxide-form aluminum stabilizer precursor can be uniformly distributed throughout the Ca-based pristine core pellets, demonstrating notably superior cyclic CO2 sorption capability and mechanical strength. The Al-fortified, core–shell structured Ca-based sorbent pellets demonstrated a peak CaO carbonation conversion rate of 54.8 % after 100 cycles when the Ca:Al molar ratio was precisely set to 85:15, which is about 2.1 times higher compared to the core–shell Ca-based sorbent pellets composed of a pure CaO core. This is primarily due to the formation of an evenly distributed inert Ca12Al14O33 within the pristine core, which effectively reduces high-temperature sintering. Hence, core–shell Ca-based sorbent pellet assembled with an Al-stabilized pristine core, could be a promising candidate for application in the CaL process for CO2 capture.
最近，具有核壳结构的钙基吸附剂被有效地生产出来，以增强吸附剂的能力。然而，对具有核壳结构的钙基颗粒的原始内核进行改性会显著影响合成吸附剂的性能，而这方面的研究仍然很少。在此，我们使用 Ca（OH）2 与铝基稳定剂前体（不溶性氧化铝和可溶性硝酸铝）混合，通过挤压-球化技术分别制备了两类铝基稳定的钙基原始内核。由于机械挤压的影响，可溶性硝酸铝会均匀地积聚在钙基原始内核中，导致其在高温煅烧阶段因硝酸铝的分解而膨胀破裂。氧化物形式的铝稳定剂前驱体可以均匀地分布在整个钙基原始芯块中，显示出明显优越的循环二氧化碳吸附能力和机械强度。当 Ca:Al 摩尔比精确设定为 85:15 时，经过 Al 强化的核壳结构 Ca 基吸附剂颗粒在 100 次循环后的 CaO 碳化转化率峰值为 54.8%，与由纯 CaO 核心组成的核壳结构 Ca 基吸附剂颗粒相比，高出约 2.1 倍。这主要是由于在原始内核中形成了均匀分布的惰性 Ca12Al14O33，从而有效地减少了高温烧结。因此，用铝稳定的原始内核组装的核壳钙基吸附剂球团有可能成为钙捕集工艺中用于捕集二氧化碳的理想候选材料。
{"title":"Aluminum-enhanced Ca-based CO2 sorbents: Core-shell assembly and the impact of stabilizer precursors","authors":"","doi":"10.1016/j.seppur.2024.129822","DOIUrl":"10.1016/j.seppur.2024.129822","url":null,"abstract":"<div><div>Lately, Ca-based sorbents with a core–shell structure have been effectively produced to augment the sorbent’s capabilities. However, modifying the pristine core of Ca-based pellets with a core–shell structure notably influences the performance of the synthesized sorbent, and research in this domain remains scarce. Here, two categories of Al-stabilized, Ca-based pristine cores were produced using Ca(OH)<sub>2</sub> mixed with Al-based stabilizer precursors of insoluble aluminum oxide and soluble aluminum nitrate, respectively, through the extrusion-spheronization technique. Due to the impact of mechanical extrusion, soluble aluminum nitrate can accumulate in-homogeneously in the Ca-based pristine core, leading to its expansion and rupture during the high-temperature calcination stage because of the decomposition of aluminum nitrate. The oxide-form aluminum stabilizer precursor can be uniformly distributed throughout the Ca-based pristine core pellets, demonstrating notably superior cyclic CO<sub>2</sub> sorption capability and mechanical strength. The Al-fortified, core–shell structured Ca-based sorbent pellets demonstrated a peak CaO carbonation conversion rate of 54.8 % after 100 cycles when the Ca:Al molar ratio was precisely set to 85:15, which is about 2.1 times higher compared to the core–shell Ca-based sorbent pellets composed of a pure CaO core. This is primarily due to the formation of an evenly distributed inert Ca<sub>12</sub>Al<sub>14</sub>O<sub>33</sub> within the pristine core, which effectively reduces high-temperature sintering. Hence, core–shell Ca-based sorbent pellet assembled with an Al-stabilized pristine core, could be a promising candidate for application in the CaL process for CO<sub>2</sub> capture.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314547","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129806
The extraction of lithium from liquid minerals, such as salt lake brines and underground brines, has garnered extensive interest due to its eco-friendly and cost-effective properties. However, the effectiveness of this method is constrained by the stability and capacity of the materials. Herein, a new-type inorganic carbon-supported H2TiO3 adsorbent was developed by a novel in-situ polymerization synchronous conversion strategy. It was found that when resorcinol and formaldehyde containing Li2CO3 and TiO2 were polymerized in-situ and then calcined at 973.15 K, the resin was successfully carbonized to obtain the carbon supporter with a low degree of disorder, and the Li2CO3 and TiO2 in the supporter were synchronously converted into Li2TiO3 and uniformly dispersed in the carbon matrix. Because of the large specific surface area and strong hydrophilicity of the carbon supporter, the material exhibited a maximum Li+ adsorption capacity of 52.14 mg·g−1, which was far higher than that of inorganic composite materials reported at present. Even the equilibrium adsorption capacity for Li+ at a low concentration of 29.26 mg·L−1 reached 28.51 mg·g−1. Following adsorption, the Li+ in the material was easily eluted by 0.25 mol·L−1 HCl, and the elution rate was more than 90 % within 2 h. Dynamic adsorption using a fixed-bed was also performed at 298.15 and 343.15 K, and the adsorption capacity for the same concentration of Li+ was 7.08 and 9.44 mg·g−1, respectively. Because of the high capacity for low-concentration Li+ and the promoting effect of temperature on adsorption, the material is well-suited for recovering Li+ from liquid resources, particularly from geothermal water with high temperatures and low Li+ concentrations.
{"title":"Inorganic porous carbon as the supporter of H2TiO3 via in-situ polymerization synchronous conversion for lithium recovery from aqueous solutions","authors":"","doi":"10.1016/j.seppur.2024.129806","DOIUrl":"10.1016/j.seppur.2024.129806","url":null,"abstract":"<div><div>The extraction of lithium from liquid minerals, such as salt lake brines and underground brines, has garnered extensive interest due to its eco-friendly and cost-effective properties. However, the effectiveness of this method is constrained by the stability and capacity of the materials. Herein, a new-type inorganic carbon-supported H<sub>2</sub>TiO<sub>3</sub> adsorbent was developed by a novel in-situ polymerization synchronous conversion strategy. It was found that when resorcinol and formaldehyde containing Li<sub>2</sub>CO<sub>3</sub> and TiO<sub>2</sub> were polymerized in-situ and then calcined at 973.15 K, the resin was successfully carbonized to obtain the carbon supporter with a low degree of disorder, and the Li<sub>2</sub>CO<sub>3</sub> and TiO<sub>2</sub> in the supporter were synchronously converted into Li<sub>2</sub>TiO<sub>3</sub> and uniformly dispersed in the carbon matrix. Because of the large specific surface area and strong hydrophilicity of the carbon supporter, the material exhibited a maximum Li<sup>+</sup> adsorption capacity of 52.14 mg·g<sup>−1</sup>, which was far higher than that of inorganic composite materials reported at present. Even the equilibrium adsorption capacity for Li<sup>+</sup> at a low concentration of 29.26 mg·L<sup>−1</sup> reached 28.51 mg·g<sup>−1</sup>. Following adsorption, the Li<sup>+</sup> in the material was easily eluted by 0.25 mol·L<sup>−1</sup> HCl, and the elution rate was more than 90 % within 2 h. Dynamic adsorption using a fixed-bed was also performed at 298.15 and 343.15 K, and the adsorption capacity for the same concentration of Li<sup>+</sup> was 7.08 and 9.44 mg·g<sup>−1</sup>, respectively. Because of the high capacity for low-concentration Li<sup>+</sup> and the promoting effect of temperature on adsorption, the material is well-suited for recovering Li<sup>+</sup> from liquid resources, particularly from geothermal water with high temperatures and low Li<sup>+</sup> concentrations.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314546","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129795
Electrolytic manganese residue (EMR) and red mud (RM) are solid wastes from electrolytic metallic manganese and alumina production. These wastes continue to accumulate, causing significant environmental damage and resource waste. To solve these problems, porous zeolite X (ERZ) was synthesized with EMR and RM as the main raw materials. ERZ was then employed to adsorb the leaching solution generated during EMR purification. Also, an investigation was carried out to ascertain the most favorable parameters for the synthesis of zeolite, and the resulting ERZ was characterized. The results indicated that the synthesized ERZ exhibits excellent crystallinity, high thermal stability, and a large specific surface area. Next, solid-state NMR (SSNMR), XRD, and Raman spectroscopy were used to characterize the ERZ synthesis process: the structural units of X zeolite are β cages and 4Rs. Additionally, the study examined the adsorption impact of ERZ on impurity ions in the leaching solution, revealing that the adsorption mechanism is chemisorption. Furthermore, the effective regeneration of ERZ demonstrated its significant practical utility. To summarize, this study presents a new feasible way for effectively utilizing EMR and BA.
{"title":"Electrolytic manganese residue and red mud co-treatment: Synthesizing zeolite X and adsorbing leaching solution from electrolytic manganese residue","authors":"","doi":"10.1016/j.seppur.2024.129795","DOIUrl":"10.1016/j.seppur.2024.129795","url":null,"abstract":"<div><div>Electrolytic manganese residue (EMR) and red mud (RM) are solid wastes from electrolytic metallic manganese and alumina production. These wastes continue to accumulate, causing significant environmental damage and resource waste. To solve these problems, porous zeolite X (ERZ) was synthesized with EMR and RM as the main raw materials. ERZ was then employed to adsorb the leaching solution generated during EMR purification. Also, an investigation was carried out to ascertain the most favorable parameters for the synthesis of zeolite, and the resulting ERZ was characterized. The results indicated that the synthesized ERZ exhibits excellent crystallinity, high thermal stability, and a large specific surface area. Next, solid-state NMR (SSNMR), XRD, and Raman spectroscopy were used to characterize the ERZ synthesis process: the structural units of X zeolite are β cages and 4Rs. Additionally, the study examined the adsorption impact of ERZ on impurity ions in the leaching solution, revealing that the adsorption mechanism is chemisorption. Furthermore, the effective regeneration of ERZ demonstrated its significant practical utility. To summarize, this study presents a new feasible way for effectively utilizing EMR and BA.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314545","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 : 2024-09-21DOI: 10.1016/j.seppur.2024.129810
Photocatalytic materials have attracted considerable attention owing to its positive environmental impact and efficiency in wastewater treatment. Herein, tin (Sn)-doped copper oxide (Cu2O) photocatalysts were successfully synthesized via a facile hydrothermal approach. The doping of Sn ions into the Cu2O lattice promoted the formation of more oxygen vacancies, which increased the separation efficiency of photogenerated carriers and enhanced photocatalytic activity. Moreover, the presence of Sn ions enhanced light absorption and the specific surface area of Cu2O, and reduced photogenerated carriers recombination. The synergistic effect of the abovementioned advantages, induced excellent photocatalytic activity to the as-prepared catalysts. Tin chloride (30 mg)-doped Cu2O showed optimal photocatalytic properties with the highest norfloxacin degradation rate of 83.9 % in 140 min under visible light irradiation. Hydroxy radicals played a major role during degradation as demonstrated by the capturing of active species experiment and EPR testing. Photocatalytic mechanisms and possible degradation pathways were proposed based on Perdew-Burke-Ernzerhof and high-performance liquid chromatography-mass spectrometry techniques. The toxicity analyses of the intermediates proved their low toxicity. Repeated cycling experiments confirmed the excellent stability of the catalysts. This work provides a feasible strategy for fabricating high-performance Cu2O-based photocatalysts.
{"title":"Introducing oxygen cacancies to tune Cu2O by Sn ion-doped for high-effective photocatalytic degradation of norfloxacin in wastewater","authors":"","doi":"10.1016/j.seppur.2024.129810","DOIUrl":"10.1016/j.seppur.2024.129810","url":null,"abstract":"<div><div>Photocatalytic materials have attracted considerable attention owing to its positive environmental impact and efficiency in wastewater treatment. Herein, tin (Sn)-doped copper oxide (Cu<sub>2</sub>O) photocatalysts were successfully synthesized via a facile hydrothermal approach. The doping of Sn ions into the Cu<sub>2</sub>O lattice promoted the formation of more oxygen vacancies, which increased the separation efficiency of photogenerated carriers and enhanced photocatalytic activity. Moreover, the presence of Sn ions enhanced light absorption and the specific surface area of Cu<sub>2</sub>O, and reduced photogenerated carriers recombination. The synergistic effect of the abovementioned advantages, induced excellent photocatalytic activity to the as-prepared catalysts. Tin chloride (30 mg)-doped Cu<sub>2</sub>O showed optimal photocatalytic properties with the highest norfloxacin degradation rate of 83.9 % in 140 min under visible light irradiation. Hydroxy radicals played a major role during degradation as demonstrated by the capturing of active species experiment and EPR testing. Photocatalytic mechanisms and possible degradation pathways were proposed based on Perdew-Burke-Ernzerhof and high-performance liquid chromatography-mass spectrometry techniques. The toxicity analyses of the intermediates proved their low toxicity. Repeated cycling experiments confirmed the excellent stability of the catalysts. This work provides a feasible strategy for fabricating high-performance Cu<sub>2</sub>O-based photocatalysts.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358970","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 : 2024-09-20DOI: 10.1016/j.seppur.2024.129812
Landfill leachate usually contains a substantial content of refractory dissolved organic matter (RDOM), which mainly consists of humic acid and fulvic acid. RDOM easily blocks the membrane pores resulting in membrane fouling when treated using membrane technologies, and it costs abundant chemical regents using advanced oxidation processes. To achieve the economically efficient treatment of RDOM in landfill leachate, this study established the electroflocculation coupled with ozone (EFCO) system. EFCO achieved a higher removal for organic matter than single electroflocculation and ozonation, where RDOM was the main component of organic matter in landfill leachate. The remaining RDOM was decomposed into lots of micromolecule weight and biodegradable proteins and lipids. Ozone improved the removal of dissolved organic matter (DOM) mainly by changing the functional groups on its surface and improving the mechanical strength of flocs to enhance the complexation between flocs and DOM. Cl2− and ClO produced in the EFCO system were the main active chlorine species, which enhanced the mineralization of RDOM. The study provides an efficient method for the pretreatment of RDOM in landfill leachate.
{"title":"Mechanism and molecular level insight of refractory dissolved organic matter in landfill leachate treated by electroflocculation coupled with ozone","authors":"","doi":"10.1016/j.seppur.2024.129812","DOIUrl":"10.1016/j.seppur.2024.129812","url":null,"abstract":"<div><div>Landfill leachate usually contains a substantial content of refractory dissolved organic matter (RDOM), which mainly consists of humic acid and fulvic acid. RDOM easily blocks the membrane pores resulting in membrane fouling when treated using membrane technologies, and it costs abundant chemical regents using advanced oxidation processes. To achieve the economically efficient treatment of RDOM in landfill leachate, this study established the electroflocculation coupled with ozone (EFCO) system. EFCO achieved a higher removal for organic matter than single electroflocculation and ozonation, where RDOM was the main component of organic matter in landfill leachate. The remaining RDOM was decomposed into lots of micromolecule weight and biodegradable proteins and lipids. Ozone improved the removal of dissolved organic matter (DOM) mainly by changing the functional groups on its surface and improving the mechanical strength of flocs to enhance the complexation between flocs and DOM. Cl<sub>2</sub><sup><img>−</sup> and ClO<sup><img></sup> produced in the EFCO system were the main active chlorine species, which enhanced the mineralization of RDOM. The study provides an efficient method for the pretreatment of RDOM in landfill leachate.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314549","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 : 2024-09-20DOI: 10.1016/j.seppur.2024.129813
The Cu-Fe bimetallic composite carbon (CuFeO2@CR) was synthesized by using the waste cation exchange resins as the carbon source to degrade carbamazepine (CBZ) by activating peroxymonulfate (PMS). Results found that 91.3 % of CBZ was degraded under the optimal condition ([PMS] = 0.2 g/L, [CuFeO2@CR] = 0.3 g/L, T = 25℃). CuFeO2@CR could efficiently degrade CBZ at pH 3.03–9.02 and maintain the degradation at 83.6 % in the fifth cycle. The reactive oxygen species (ROS) were SO4•−, •OH, and 1O2 with the relative contribution of 35 %, 29 %, and 36 %, respectively. DFT calculation demonstrated that CuFeO2@CR exhibited a preferential affinity for PMS and greater transfer electrons capacity than CR. Three reaction pathways were proposed in the CuFeO2@CR/PMS system, and the degradation could effectively reduce the toxicity into non-toxic. The continuous flow catalytic experiment indicated the promising application in the treatment of antibiotic wastewater. This work provides guidance and theoretical support for CBZ degradation mechanisms.
{"title":"The efficient degradation of carbamazepine by Cu-Fe bimetallic composite carbon derived from the waste cation exchange resins: Mechanism, ecotoxicity, and continuous flow catalysis","authors":"","doi":"10.1016/j.seppur.2024.129813","DOIUrl":"10.1016/j.seppur.2024.129813","url":null,"abstract":"<div><div>The Cu-Fe bimetallic composite carbon (CuFeO<sub>2</sub>@CR) was synthesized by using the waste cation exchange resins as the carbon source to degrade carbamazepine (CBZ) by activating peroxymonulfate (PMS). Results found that 91.3 % of CBZ was degraded under the optimal condition ([PMS] = 0.2 g/L, [CuFeO<sub>2</sub>@CR] = 0.3 g/L, T = 25℃). CuFeO<sub>2</sub>@CR could efficiently degrade CBZ at pH 3.03–9.02 and maintain the degradation at 83.6 % in the fifth cycle. The reactive oxygen species (ROS) were SO<sub>4</sub><sup>•−</sup>, •OH, and <sup>1</sup>O<sub>2</sub> with the relative contribution of 35 %, 29 %, and 36 %, respectively. DFT calculation demonstrated that CuFeO<sub>2</sub>@CR exhibited a preferential affinity for PMS and greater transfer electrons capacity than CR. Three reaction pathways were proposed in the CuFeO<sub>2</sub>@CR/PMS system, and the degradation could effectively reduce the toxicity into non-toxic. The continuous flow catalytic experiment indicated the promising application in the treatment of antibiotic wastewater. This work provides guidance and theoretical support for CBZ degradation mechanisms.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314544","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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