ENERGY & FUELS
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2021
·
IF 3.605
Jinjin Li,Xiuwei Ma,Hao Wu,Linjun Yang
A large amount of water vapor present in low-concentration organic exhaust gases severely inhibited the adsorption of volatile organic compounds (VOCs). In this paper, three coal-based activated carbon samples were prepared by heat treatment, sodium hydroxide impregnation, and ammonia solution impregnation and were analyzed by N2 adsorption isotherm, X-ray photoelectron spectroscopy (XPS), Boehm titration, and water and toluene adsorption isotherms. Besides, the low-concentration toluene adsorption performance of samples was investigated under different humidities, and the desorption activation energies (DAEs) of toluene and water on samples were estimated through temperature programmed desorption (TPD) experiments. Furthermore, the effect of molecule polarity was investigated under 0 and 60 RH%. The results indicated that samples treated by heating (CAC-1) significantly improved the uptake of low-concentration toluene under humid conditions compared to samples modified by alkali impregnation, which is related to surface chemistry. The analysis confirmed that CAC-1 possessed more graphitic (C + N), enhancing the π–π interaction, and possessed lower acidic groups, reducing the bonding sites with water. The Yoon and Nelson (Y–N) model indicated that CAC-1 presented a higher diffusion rate of toluene than CAC under high humidity. TPD experiments further demonstrated that the CAC-1 had smaller DAE of water and larger DAE of toluene, suggesting a stronger hydrophobic and stronger interaction with toluene. In addition, the experiments demonstrated that CAC-1 had superior adsorption performance both for polar and weakly polar VOCs at high humidity, especially for weakly polar VOCs. These conclusions would help to emphasize that activated carbons after heat treatment have better selectivity in removing low-concentration VOCs from high-humid conditions.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2016
·
IF 7.476
Lei Liu,Diming Zhang,Qian Zhang,Xing Chen,Gang Xu,Yanli Lu,Qingjun Liu
Volatile organic compounds (VOCs) detection is in high demand for clinic treatment, environment monitoring, and food quality control. Especially, VOCs from human exhaled breath can serve as significant biomarkers of some diseases, such as lung cancer and diabetes. In this study, a smartphone-based sensing system was developed for real-time VOCs monitoring using alternative current (AC) impedance measurement. The interdigital electrodes modified with zinc oxide (ZnO), graphene, and nitrocellulose were used as sensors to produce impedance responses to VOCs. The responses could be detected by a hand-held device, sent out to a smartphone by Bluetooth, and reported with concentration on an android program of the smartphone. The smartphone-based system was demonstrated to detect acetone at concentrations as low as 1.56 ppm, while AC impedance spectroscopy was used to distinguish acetone from other VOCs. Finally, measurements of the exhalations from human being were carried out to obtain the concentration of acetone in exhaled breath before and after exercise. The results proved that the smartphone-based system could be applied on the detection of VOCs in real settings for healthcare diagnosis. Thus, the smartphone-based system for VOCs detection provided a convenient, portable and efficient approach to monitor VOCs in exhaled breath and possibly allowed for early diagnosis of some diseases.
研究领域:
环境科学
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生物医学工程
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分析化学
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移动健康技术
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DOI
PubMed
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 45
·e202201614
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IF 2.307
Yafei Zhao,Ye Zhuang,Kai Ye,Yifei Wu,Changhe Luo,Dan Li,Yi Zhang,Jin Yao,Sajid Ali
Graphical To test the VOCs treatment performance of plasma catalysis at a pilot scale (50 m 3 /h), a novel multi-tube DBD coupled with Ag-MnO x /Al 2 O 3 was built, and the toluene (30 mg/m 3 ) removal efficiency and energy yield achieved by the system were 85.4 % and 5.2 g/kWh at the SED of 39.7 J/L, which were nearly three times as much as the single DBD. A pilot-scale multi-tube dielectric barrier discharge (DBD) reactor coupled with a series of Mn−Ag based catalysts for VOCs abatement was set up and investigated. The DBD with 2 %Ag-MnO x /Al 2 O 3 catalyst exhibited the best performance of removal efficiency (85.4 %) and energy yield (5.2 g/kWh) of toluene at the specific energy density of 39.7 J/L, much higher than the single DBD reactor (34.9 %, 2.1 g/kWh). Moreover, the degradation efficiencies of styrene, dimethyl, ethyl acetate and xylene in the plasma catalysis system were also studied. The catalyst presented high stability during the 50 hours of toluene plasma-catalysis oxidation. Finally, the physicochemical properties of this catalyst were characterized and discussed using an energy dispersive spectrometer, X-ray diffraction patterns, and X-ray photoelectron spectroscopy.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2016
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IF 8.328
Xufang Qian,Dongting Yue,Zheyi Tian,Meng Reng,Yao Zhu,Miao Kan,Taiyang Zhang,Yixin Zhao
We incorporated highly stable carbon quantum dots (CQDs) with Bi 2 WO 6 to sufficiently photocatalytic removal of gaseous volatile organic compounds (VOCs) utilize solar energy. With the facile decoration of CQDs, the composite photocatalysts of CQDs/Bi 2 WO 6 extend the absorption into visible light region and improve the photoexcited charge separation in comparison with pristine Bi 2 WO 6 . The CQDs/Bi 2 WO 6 exhibited higher photocatalytic oxidation activities towards acetone and toluene under both UV–vis and visible light irradiation. In all, CQDs could be a promising candidate for visible light photocatalysts due to their superior ability to extend the visible absorption and suppress the photo-excited charge recombination.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Xue Gao,Kai Zheng,Qiyan Zhang,Xiaoqing Cao,Shan Wu,Jixin Su
In this work, the TiO 2 -RGO/LDHs photocatalyst was synthesized by a hydrothermal method using GO/LDHs as substrates. The structure and property of prepared materials were characterized via XRD, SEM, EDS, XPS, TEM, UV–vis spectroscopy, etc. Toluene, methanol, and ethyl acetate were selected as typical volatile organic pollutants model pollutants to examine the photocatalytic degradation effect of TiO 2 -RGO/LDHs. The photocatalytic efficiency of the TiO 2 -RGO/LDHs system was further investigated in contaminated air (NOx = 20 ppm). The results indicated that the prepared TiO 2 -RGO/LDHs nanocomposite possess better photodegradation activity than pure TiO 2 and TiO 2 -RGO samples, and the photocatalyst has excellent application for the elimination of three kinds of VOCs. The photochemical and materials characterization revealed that the graphene has enlarged the light response range and inhibited the recombination of electron-hole pairs of TiO 2 . Meanwhile, LDHs can offer more hydroxide ions to accelerate the oxidation reaction, resulting in more radicals and better pollutants degradation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2022
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IF 6.796
Ruijie Xie,Dongxue Lei,Xiaowen Xie,Ziyi Suo,Dennis Y.C. Leung,Jianping Cao,Fang Ruimei,Haibao Huang
Vacuum ultraviolet (VUV) photolysis is a facile method for volatile organic compounds (VOCs) elimination, but is greatly limited by the relatively low removal efficiency and the possible secondary pollution. To overcome above drawbacks, we developed an efficient method for VOCs elimination via VUV photolysis coupled with wet scrubbing process. In this coupled process, volatile toluene, a representative of VOCs, was oxidized by the gas-phase VUV photolysis, and then scrubbed into water for further oxidation by the liquid-phase VUV photolysis. More than 96% of toluene was efficiently removed by this coupled process, which was 2 times higher than that in the gas-phase VUV photolysis. This improvement was attributed to the synergistic effect between gas-phase and liquid-phase VUV photolysis. O 3 and HO • are the predomination reactive species for the toluene degradation in this coupled process, and the generation of O 3 in gas-phase VUV photolysis can efficiently enhance the HO • production in liquid-phase VUV photolysis. The result from in-situ proton transfer reaction ionization with mass analyzer (PTR-MS) further suggested that most intermediates were trapped by the wet scrubbing process and efficiently oxidized by the liquid-phase VUV photolysis, showing a high performance for controlling the secondary pollution. Furthermore, the result of stability test and the reuse of solution demonstrated that this coupled process has a highly stable and sustainable performance for toluene degradation. This study presents an environmentally benign and highly efficient VUV photolysis for gaseous VOCs removal in the wet scrubbing process.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Mengmeng Lou,Jingzi Li,Xiaowei Zhu,Jingchao Chen,Xingran Zhang,Xiaofeng Fang,Fang Li
Photothermal membrane distillation (PMD) has the potential to address freshwater scarcity, but heat loss during heat transfer from the photothermal surface to the feed bulk inevitably lower the photothermal-vapor conversion efficiency of this process. The permeation of VOCs during PMD also threatens the recycling of distilled water. Herein, a zeolitic imidazolate framework-67 (ZIF-67) wrapped graphene membrane (ZGM) was developed and used for the PMD process. The results demonstrated that the hierarchical porous structure and low heat conductivity of ZIF-67 endowed the ZGM with improved light absorbance and heat localization, thus sustaining a high cross-membrane temperature gradient . Under simulated sunlight illumination, the ZGM attained an additional flux of 0.91 kg m −2 h −1 , corresponding to a photothermal efficiency of 62.1%, which was 183.2% higher than that of the pristine membrane. The temperature change near the photothermal coating was simulated, which showed that ZGM had slower heat conduction into the feed, demonstrating a confined heat effect. Meanwhile, the ZGM exhibited a good interception for phenol when peroxymonosulfate (PMS) was added to the hot feed. The distilled phenol concentration was 88.0% lower than that of the PMD without PS. Electron paramagnetic resonance (EPR) and radical quenching experiments verified that singlet oxygen ( 1 O 2 ) was the dominant reactive oxygen species during in-situ phenol degradation. This work provides a new strategy to develop advanced photothermal membranes to simultaneously promote the photothermal performance and VOC interception.
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产品关联
DOI
高影响因子
Marine Drugs
·
2021
·Vol. 19
·期 4
·192
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IF 5.118
Pengrui Wang,Jiapeng Chen,Lujing Chen,Li Shi,Hongbing Liu
Plant volatile organic compounds (VOCs) represent a relatively wide class of secondary metabolites. The VOC profiles of seven seaweeds (Grateloupia filicina,Polysiphonia senticulosa,Callithamnion corymbosum,Sargassum thunbergii,Dictyota dichotoma,Enteromorpha proliferaandUlva lactuca) from the Yellow Sea of China were investigated using multifiber headspace solid phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC–MS), among them, the VOCs of three red algae Grateloupia filicina, Polysiphonia senticulosa, and Callithamnion corymbosum were first reported. Principal component analysis (PCA) was used to disclose characteristic categories and molecules of VOCs and network pharmacology was performed to predict potential biomedical utilization of candidate seaweeds. Aldehyde was found to be the most abundant VOC category in the present study and (E)-β-ionone was the only compound found to exist in all seven seaweeds. The chemical diversity of aldehydes inE. proliferasuggest its potential application in chemotaxonomy and hinted that divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber is more suitable for aldehyde extraction. VOCs inD. dichotomawere characterized as sesquiterpenes and diterpenes and the most relevant pharmacological pathway was the neuroactive ligand–receptor interaction pathway, which suggests thatD. dichotomamay have certain preventive and therapeutic values in cancer, especially in lung cancer, in addition to neuropsychiatric diseases.Keywords:volatile organic compounds;seaweeds;characteristic VOCs;chemotaxonomy;biomedical utilization;headspace solid phase microextraction
研究领域:
植物化学
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药理学
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海洋生物学
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DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 19
·4691
·
IF 4.2
Wei Lan,Wei Cheng,Ruilong Li,Mei Zhang,Mengmeng Li,Yuan Zhang,Yibin Zhou
Fruit wine production is a practical approach for extending the shelf life and enhancing the value of strawberries (Fragaria×ananassa). Fruit cultivars and juices are important sources of volatile organic compounds (VOCs) that determine fruit wine sensory quality. In this study, VOCs in the juices and wines of four strawberry cultivars were identified using two-dimensional gas chromatography-time-of-flight mass spectrometry, and a sensory analysis of the wines was performed. A total of 1028 VOCs were detected. PCA and OPLS-DA distinguished the four cultivars from which the juices and wines were made. Six VOCs with variable importance in projection values greater than one were the main aroma and flavor components of strawberry wines. ZJ wine had the highest sensory scores for coordination (9.0) and overall evaluation (8.9) among the 18 descriptors of strawberry wine evaluated. Overall, the ZJ wine had the highest alcohol content (13.25 ± 0.59%,v/v) and sensory evaluation score, indicating that the ZJ cultivar is more suitable for fermentation. This study reflects the differences between wines made from four strawberry cultivars and provides a reference for brewing fruit wines.
研究领域:
食品科学
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农学
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分析化学
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酿酒学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Xiuquan Li,Li Zhang,Zhongqing Yang,Ziqiang He,Peng Wang,Yunfei Yan,Jingyu Ran
In engineering applications, moisture is inevitable in waste gas containing VOCs, which leads to the problem of poor adsorption performance of activated carbon under humid conditions. To improve the adsorption selectivity of VOCs, walnut based activated carbon was modified by polydimethylsiloxane (PDMS) and characterized by FTIR analysis, SEM&EDS and the static water contact angle. Dynamic adsorption column experiments were conducted and Yoon-Nelson (Y-N) model was used to identify adsorption effect for benzene on ACs when relative humidity was 0%, 30%, 60%, 90%. The results show that the activated carbon modified by PDMS increases Si and O elements and forms a hydrophobic coating on the surface in the form of Si-O-Si group. The hydrophobicity changed positively with the increase of modification temperature, but the collapse and blockage of pores were more serious. Adsorption capacity of hydrophilic Bare-AC decreased by 55.9% when the relative humidity increased from 0% to 90%. However, the activated carbon covered with PDMS modified at 200 °C decreased by only 19.3%. Changes in the mass transfer rate of benzene during adsorption under different conditions have also been discovered. This study provides a method to solve the problem of serious deterioration of adsorption capacity of adsorbents in wet environment.
研究领域:
环境工程
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材料科学
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DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 9
·726
·
IF 3.444
Jian Wang,Hainan Zhao,Jianfei Song,Tingyu Zhu,Wenqing Xu
Manganese oxide catalysts, including γ-MnO2, Mn2O3and Mn3O4, were synthesized by a precipitation method using different precipitants and calcination temperatures. The catalytic oxidations of benzene and 1,2-dichloroethane (1,2-DCE) were then carried out. The effects of the calcination temperature on the catalyst morphology and activity were investigated. It was found that the specific surface area and reducibility of the catalysts decreased with the increase in the calcination temperature, and both the γ-MnO2and Mn3O4were converted to Mn2O3. These catalysts showed good activity and selectivity for the benzene and 1,2-DCE oxidation. The γ-MnO2exhibited the highest activity, followed by the Mn2O3and Mn3O4. The high activity could be associated with the large specific surface area, abundant surface oxygen species and excellent low-temperature reducibility. Additionally, the catalysts were inevitably chlorinated during the 1,2-DCE oxidation, and a decrease in the catalytic activity was observed. It suggested that a higher reaction temperature could facilitate the removal of the chlorine species. However, the reduction of the catalytic reaction interface was irreversible.Keywords:benzene;1,2-Dichloroethane;catalytic oxidation;manganese oxide catalysts
研究领域:
环境科学
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催化化学
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DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2024
·Vol. 18
·期 9
·1-11
·
IF 4.3
Lu Xikai,Zhang Chunyan,Wu Meng,Liu Wenjie,Xue Bin,Yao Chao,Li Xiazhang
Photothermal catalytic oxidation emerges as a promising method for the removal of volatile organic compounds (VOCs). Herein, via sol-gel impregnation method, spinel CuMn 2 O 4 was coated on attapulgite honeycombs with integrating biochar (BC) film as the second carrier, using chestnut shell as complexation agent. Various mass ratios of CuMn 2 O 4 to chestnut shell was modulated to investigate the catalytic toluene degradation performance. Results indicated that the monolithic CuMn 2 O 4 /BC/honeycomb catalyst demonstrated superior photothermal catalytic toluene degradation with a low T 90 (temperature at 90% degradation) of 263 °C when the mass ratio of CuMn 2 O 4 to biomass was 1:4. The addition of BC film substantially increased the honeycomb’s specific surface area and improved the photothermal conversion of spinel, leading to enhanced photothermal catalytic activity. This study presents a cost-effective strategy for eliminating industrial VOCs using clay-biomass based monolithic catalyst.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
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