SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Lilin Fang,Peng Cui,Dongni Liu,Xiaosi Sun,Hao Ren,Hanyu Zhang,Yan Huang,Wenshuai Zhu,Zhichang Liu
The polycyclic aromatic hydrocarbons (PAHs) are serious organic contaminants that are produced naturally and anthropogenically. The separation of PAHs by adsorption approach provides an efficient method to avoid the negative effects of PAHs pollution. In this study, cyclodextrin (CD) was grafted to chitosan (CS) by using glutaraldehyde as crosslinking agent to construct shaped CD-CS polymers and carbonization was executed subsequently. The carbonized β-CD-CS-1000 exhibited a significant increasement of BET surface area (CD-CS polymer: 1 m 2 ·g −1 ; β-CD-CS-1000: 1083 m 2 ·g −1 ) and great PAHs adsorption performance (anthracene: 106.34 mg/g; acenaphthylene: 41.02 mg/g). The adsorption kinetic behavior and the equilibrium adsorption process were further explored. β-CD-CS-1000 showed good cyclic adsorption capacity and anti-interference stability with the xylenes as interferon. Furthermore, the adsorbents based CD-CS can be synthesized at the gram-level in the lab and exhibited great adsorption capacity in real diesel. The large-scale preparation of shaped CD-CS adsorbents made it possible to be applied to the petrochemical industry.
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ANALYTICA CHIMICA ACTA
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2024
·
IF 5.7
Min Sun,Jiaqing Feng,Yang Feng,Xubo Xin,Yali Ding,Juanjuan Feng
Background Because of the advantages of good selectivity , high sensitivity, and fast analysis, high performance liquid chromatography (HPLC) has become one of the modern analytical techniques in wide application range, such as biological analysis, environmental detection, pharmaceutical and food inspection, agriculture and other fields. The stationary phase greatly decides the chromatographic separation performance, so the development of novel stationary phase is most important for HPLC. Results Pyridyl conjugated microporous polymers (P-CMP) with one to four layers were modified on the surface of amino silica to obtain a novel core-shell material (SiO2@P-CMP) by the layer-by-layer assembly strategy and Chichibabin reaction . The relationship between the structure of SiO2@P-CMP and chromatographic performance was carefully investigated, and the retention mechanism was revealed. The interactions including π-π stacking, hydrophobic effect and hydrogen bond gradually enhanced with the increase of P-CMP layers on the silica surface. Compared with C18 column, SiO2@P-CMP columns displayed better separation selectivity for polycyclic aromatic hydrocarbons (PAHs). According to the relative retention values ( α ), the separation performance of SiO2@P-CMP columns ( α = 1.144–1.884) for PAH isomers and other analytes was obviously better than that of C18 column ( α = 0.998–1.487). Furthermore, the SiO2@P-CMP column with four layers was selected to separate different types of analytes (eight PAHs, four bisphenols , four estrogens and nine phthalates), and the peak order of analytes was different from that on the C18 column due to the influence of hydrogen-bonding and π-π interactions. The relative standard deviations (n = 10) of retention time and peak area on SiO2@P-CMP column were between 0.28 % and 1.98 %. Significance and novelty Pyridyl conjugated microporous polymer was introduced as the stationary phase for the first time in HPLC. The proposed column displayed better separation characteristics compared to Zorbax SB-C 18 column. It provided a new idea for the separation of small molecules and the development of chromatographic packing or extraction material.
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ANALYTICAL LETTERS
·
2024
·
IF 1.6
Tianhan Zhang,Chengyi Xie,Yong Wu,Wenqing Gao,Chenlu Wang,Keqi Tang,Jiancheng Yu
A compact in-trap single photon ionization (SPI) system, termed discontinuous atmospheric pressure interface (DAPI) ion trap mass spectrometry (ITMS), for the rapid determination of trace volatile organic compounds (VOCs). DAPI enables the maintenance of high analyte pressure in the SPI source while preserving the vacuum. Utilizing vacuum ultraviolet (VUV) lamp as the ion source, we ionize the analyte within an enclosed miniature 3D ion trap for efficient analysis. Experimental findings demonstrate that the system achieves a mass resolution of less than 0.5 atomic mass units for full width at half maxima (FWHM), providing unit resolution. For the response for benzene, the system achieves almost instantaneous response, with rise and fall times of only 2 s, which is a significant advantage compared to the membrane inlet (MI) approach necessary for on-site detection. Additionally, tandem mass spectrometry (MS/MS) with unit m/z isolation window was achieved and resolved dimethyl disulfide and phenol with similar molecular weights. Our results demonstrate that the system provides excellent performance and we anticipate its application in rapidly determining VOCs.
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JOURNAL OF CHROMATOGRAPHY A
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2024
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IF 3.8
Yali Yang,Jia Chen,Xiaojing Liang,Bei Liu,Kaijun Quan,Xiuhui Liu,Hongdeng Qiu
In this paper, three imidazole- and C18- bifunctional silica stationary phases (Sil-Im-C18) were prepared by adjusting introduction interval of octadecyltrichlorosilane (ODS) and 3-imidazol-1-ylpropyl(trimethoxy)silane (TMPImS), which can be used for reversed-phase liquid chromatography (RPLC) and ion exchange chromatography (IEC) with adjustable performance. The successful preparation of Sil-Im-C18 were confirmed by the characterizations of elemental analysis, infrared spectroscopy (FTIR) and contact angle (CA). Chromatographic performance of Sil-Im-C18 were evaluated by the separation of Tanaka test mixture, alkylbenzenes, linear PAHs and a set of analytes with different properties (uracil, phenol, 1,2-dinitrobenzene and naphthalene), and compared with commonly used C18 column. It was found that the chromatographic performance of Sil-Im-C18 changed significantly with the difference in bonding amount of imidazole and C18. Sil-Im-C18 demonstrated the excellent separation performance towards polycyclic aromatic hydrocarbons (PAHs), phenylesters, phenylamines , phenols and inorganic anions, and notably, nucleobases and nucleosides can be separated using pure water as mobile phases . The van Deemter plot showed that the column efficiency of Sil-Im-C18-3 was 64,933 plate· m − 1 for naphthalene, indicated that Sil-Im-C18 was reasonably chromatographic columns. The RSD values of retention time were 0.22 %-0.61 % for 10 needles alkylbenzenes injected continuously at 50 °C to investigate thermal stability and repeatability, all the fluctuations of k of naphthalene were less than 2.3 % for Sil-Im-C18-1 during flushing 24 h with the mobile phase at different pH values (pH = 3 and 8), the retention time of alkylbenzenes were almost same for Sil-Im-C18-1 at different time, the RSD values of retention time of alkylbenzenes were 0.45 %-2.28 % for two batches Sil-Im-C18-1, revealing the excellent repeatability, thermal stability, durability and reproducibility of Sil-Im-C18, and implying a commercial prospect.
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JOURNAL OF HAZARDOUS MATERIALS
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2025
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IF 11.3
Yuqian Li,Haomin Chen,Wei Li,Beidou Xi,Caihong Huang
The remediation of sites co-contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) poses challenges for efficient and ecofriendly restoration methods. In this study, three strains ( Pseudomonas sp. PDC-1, Rhodococcus sp. RDC-1, and Enterobacter sp. EDC-1) were isolated from sites contaminated with PAHs and HMs. The constructed bacteria consortium was then immobilized using biochar, bentonite, and peat. The immobilized bacteria consortium (IBC) demonstrated efficient removal ability of phenanthrene (58.1 %-73.4 %) and benzo[ a ]pyrene (69.6 %-83.5 %) during 60 days. Additionally, the IBC decreased soil bacterial richness and diversity, but increased the relative abundance of Proteobacteria phylum and Ochrobactrum genus, which were capable of degrading PAHs. Soil microbial co-occurrence network with IBC was classified into three main modules, and 14 genera were identified as keystone taxa linked to PAHs degradation and HMs resistance. The IBC enhanced the dioxygenase metabolic pathways for PAHs degradation, including phthalic acid and salicylic acid pathways, which became the main driving factor affecting PAHs removal efficiency based on the structural equation modeling analysis. This study confirmed the potential application of the constructed IBC in the bioremediation of soil co-contaminated with PAHs-HMs, and provides insights into key removal mechanism and main driving factor of the enhanced elimination of PAHs.
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Catalysts
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2024
·Vol. 14
·期 12
·924
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IF 3.8
Yu Yue,Guozhi Zhu,Min Liu,Yue Zhu,Weilong Ji,Xiaoqin Si,Tianliang Lu
As an important biomass resource, γ-valerolactone (GVL) shows considerable potential for applications in biofuel production, organic synthesis, polymer, and food industries. Herein, an effective method was presented for synthesizing GVL through the catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) under mild conditions. Using isopropanol as a hydrogen donor, a 100% conversion of ethyl levulinate and an 88.7% yield of GVL were achieved over 2%Zr-Beta-7d catalyst at 110 °C for 8 h. The acidic sites of synthesized Zr-Beta via hydrothermal methods easily adjusted and offered high catalytic activity and selectivity. The Lewis (L) acid sites on the zeolite serve as the active centers for the conversion of EL. Characterization results indicate that the amounts of L acid sites on Zr-Beta increased with the Zr content and crystallization time rose, thus enhancing the selectivity for GVL. Additionally, the influences of catalyst dosage, reaction temperature, and time on catalytic performance are studied, as well as calculations of kinetic parameters such as reaction rate constants and activation energies. The 2%Zr-Beta-7d catalyst retains its high performance after five cycles. The current research may present an efficient approach for the conversion of EL to GVL under mild conditions.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2024
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IF 3.7
Pengcheng Hu,Jinke Yang,Aonan Lai,Shufeng Zhou
The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid (IL) were investigated. The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL. As the water concentration increased to 65 mg·g –1 , the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%, and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201. When the concentration of impurities increased to a critical value, the chloroaluminate IL began to deactivate, leading to a decrease in naphthalene conversion. The critical concentrations for ethanolamine, water, methanol, ether, and diisopentyl sulfide were 33 mg·g –1 , 65 mg·g –1 , 67 mg·g –1 , 87 mg·g –1 , and 123 mg·g –1 , respectively. Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation. The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27 Al NMR spectroscopy. 2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better, but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks. 2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL. With the increase in water concentration, the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid, and the Lewis acid gradually decreased, while the Brønsted acid showed a change of increasing first and then decreasing.
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Journal of Energy Chemistry
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2024
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IF 14
Wen-Jing Zhang,Yan-Cheng Hu,Yan-Hong Tan,Jia Li,Ning Li,Jing-Pei Cao
High-energy-density (HED) fuel (e.g. widely used JP-10 and RJ-4), featuring compact 3D polycyclic structure with high strain, is of critical importance for volume-limited military aircraft, since their high density and combustion heat can provide more propulsion energy. To reduce the reliance on petroleum source, it is highly desirable to develop renewable alternatives for the production of strained polycyclic HED fuel, but which remains a big challenge because of the inaccessibility caused by the high strain. We herein demonstrate a three-step catalytic route towards highly strained C 17 and C 18 spirofuel with biomass feedstocks. The process includes catalytic aldol condensation of renewable cyclohexanone/cyclopentanone with benzaldehyde, catalytic spiro Diels-Alder (D-A) reaction of aldol adduct with isoprene, and catalytic hydrodeoxygenation. The key spiro D-A reaction is enabled by the catalysis of heterogeneous Lewis acidic ionic liquid. The chloroaluminate IL, formed by benign urea and AlCl 3 , exhibits good catalytic performance and reusability for this step. An eventual hydrodeoxygenation (HDO) over Pd/C and H-Y produces strained tricyclic spirofuel with density >0.93 g/mL, combustion heat >41 MJ/L and freezing point < −40 °C, which are better than the properties of tactical fuel RJ-4. Therefore, it is anticipated that the as-prepared renewable fuels have the potential to replace traditional petroleum-derived HED fuels.
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Journal of Water Process Engineering
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2024
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IF 6.3
Hai-Xu Zou,Yang-Yang Xu,Xing Fan,Feng-Yun Ma,Wei-Dong Cao,De-Quan Li,Jia-Feng Song
Simulated wastewater samples, representative of coal chemical industry and comprising major constituents such as phenol , p -cresol, o -cresol, and naphthalene , were subjected to treatment in a range of catalytic ozonation systems. To prepare the catalysts for ozonation, three series of metal oxides, iron oxides , manganese oxides , and cerium oxides, were manufactured onto the surface of γ-Al 2 O 3 support in varying loadings. The determination of the optimal loading amount for each catalyst was based on the observed removal efficiency of chemical oxygen demand (COD) in phenol-containing aqueous solution. Primary small molecular organic acids formed in the aqueous solution during the degradation of phenol were analyzed by ion chromatography . The decomposition of ozone without catalyst can directly oxidize phenol, and catalytic ozonation can reach the same goal through the generation of OH. The synergy effects between ozone and the catalysts facilitate the production of highly reactive oxidizing species, leading to more efficacious degradation of phenol and an increased total concentration of organic acids till 37.8 mg/L. Radical capture experiments revealed that the generation of OH within the catalyzed ozonation system is associated with the presence of oxygen defects on the catalyst's surface, which significantly influenced the catalytic efficacy during the ozonation process. A loading of 20 %CeO2 on γ-Al2O3 support exhibited the best COD removal rate as high as 90 % due to the increased availability of lattice oxygen participating in catalytic ozonation. Thus, the methodology built for the optimization of ozonation catalyst is proven a promising way to prepare candidate catalyst for the treatment of wastewater from coal chemical industry.
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TALANTA
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2014
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IF 3.511
Man Wang,Shihai Cui,Xiaodi Yang,Wentao Bi
An easy preparation of g-C 3 N 4 /Fe 3 O 4 nanocomposites by chemical co-precipitation has been demonstrated. The as-prepared materials were characterized by X-ray diffraction, transmission electron microscopy , Fourier transform infrared spectroscopy and thermogravimetric analysis . The high affinity of g-C 3 N 4 toward polycyclic aromatic hydrocarbons and the magnetic behavior of Fe 3 O 4 were combined to provide an efficient and simple magnetic solid phase extraction (MSPE). The adsorption and desorption of polycyclic aromatic hydrocarbons on g-C 3 N 4 /Fe 3 O 4 were examined. Different factors affecting the magnetic solid phase extraction of polycyclic aromatic hydrocarbons were assessed in terms of adsorption, desorption, and recovery. Under the optimized conditions, the proposed method showed good limits of detection (LOD, S/N=3) in the range of 0.05–0.1 ng mL −1 and precision in the range of 1.8–5.3% (RSDs, n =3). This method was also successfully applied to the analysis of real water samples; good spiked recoveries over the range of 80.0–99.8% were obtained.
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JOURNAL OF HAZARDOUS MATERIALS
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2024
·
IF 12.2
Ziyue Li,Xiaolei Wang,Fei Peng,Ning Chen,Guodong Fang
The use of peracetic acid (PAA) in advanced oxidation processes has gained significant attention recently, but the knowledge of activating PAA to degrade polycyclic aromatic hydrocarbons (PAHs) is limited due to the variety and selectivity of reactive substances in PAA oxidation system. This paper presented the first systemically study on the degradation of PAHs by PAA activation in soil. It was found that heat-activated peracetic acid (heat/PAA) was capable of degrading phenanthrene (PHE) efficiently with degradation efficiency > 90 % within 30 min. Experimental results demonstrated that a series of reactive oxygen species (ROS) including organic radicals (RO • ), hydroxyl radicals (HO • ) and singlet oxygen ( 1 O 2 ) were generated, while acetylperoxyl (CH 3 C(O)OO • ) and acetyloxyl (CH 3 C(O)O • ) radicals were primarily responsible for PHE degradation in soil. Further analysis shows that polymerization products such as diphenic acid , 2′-formyl-2-biphenylcarboxylic acid and other macromolecules were dominant products of PHE degradation, suggesting polymerization driving PHE degradation instead of the conventional mineralization process. Toxicity analysis shows that most of the polymerization products had less toxicity than that of PHE. These results indicate that PAA activation was a highly effective remediation method for PAHs contaminated soil, which also provided a novel mechanism for pollutant degradation with the PAA activation process for environmental remediation.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Gankai Huang,Xinyi Huang,Junlin Huang,Xuye Hou,Youquan Zhang,Fang Lai,Ronghui Lin,Kangquan He,Qunhua Long,Hongbing Ji,Kungang Chai
Efficient purification of xylene isomers, particularly the separation of para- / meta -xylenes (PX/MX), is industrially crucial but challenging. Here, we report a classical aluminum-based metal–organic framework (MIL-160) that exhibits an exceptional meta-selectivity in liquid-phase competitive adsorption of xylene isomers. The outstanding separation performance of MIL-160 for xylene isomers is confirmed by dynamic breakthrough experiments. The PX eluted first and breakthrough of MX didn’t occur until a long retention times, which is in accordance with the results observed from static adsorption experiment. Molecular simulations and calculations suggested that the largest affinity of MIL-160 toward MX, potentially due to the good fitness between the 1D square-shaped channel and MX. To improve the productivity of purified PX in continuous separation mode, we speculated that combining the MX-selective property of MIL-160 and the previously reported ortho -xylene (OX)-selective property of CAU-23 can enhance the separation effect between PX and the other two isomers. So, MIL-160 and CAU-23 were filled simultaneously in column and the effect of mass ratio of them on PX productivity was investigated. The results indicated that when the mass ratio of MIL-160 versus CAU-23 was 4:6, MX and OX almost simultaneously eluted and reached saturation, which can maximize the productivity of PX. This study offers a feasible strategy for isolating PX from xylene isomer with low energy consumption and high efficiency.
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