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Benzene, toluene and xylenes levels in new and used vehicles of the same model 认领 引用 被引量：9
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作者 Joanna Faber Krzysztof Brodzik +1 位作者 Anna Go da-Kopek Damian Lomankiewicz 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2013年第11期2324-2330,共7页
The aim of this work was to determine the level of benzene, toluene, o-xylene and m, p-xylene （BTX） in air samples collected from the cabins of new and used vehicles of the same model. Ten new vehicles were examined... The aim of this work was to determine the level of benzene, toluene, o-xylene and m, p-xylene （BTX） in air samples collected from the cabins of new and used vehicles of the same model. Ten new vehicles were examined in order to check interior emission from materials used to equip the passenger compartment. In order to compare and define the impact of exhaust gases, air samples were also collected from two used cars, at different mileages （up to 20,000 kin）. All vehicles tested were of the same type. Samples were collected onto Carbograph 1TD sorbent, thermally desorbed and examined with the use of gas chromatography with flame ionisation and mass spectrometry detectors. All results obtained were referred to Polish and German requirements for indoor air quality （both in public buildings and in workspace environments）. Average benzene, toluene, o-xylene and m, p-xylene concentrations in new cars were determined at the level of 11.8 μg/m^3, 82.7 μg/m^3, 21.2 μg/m^3 and 89.5 μg/m^3, respectively. In the used cars, BTX concentration increased with increasing vehicle mileage. The most significant increase of BTX concentration was observed above 11,000 km mileage. 展开更多
关键词 benzene, toluene, xylenes interior emission vehicle＇s interior indoor air quality thermal desorption gas chromatography
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Bio-removal of mixture of benzene,toluene,ethylbenzene,and xylenes/total petroleum hydrocarbons/trichloroethylene from contaminated water 认领 引用 被引量：3
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作者 SHIM Hojae MA Wei +1 位作者 LIN Aijun CHAN Kaicho 《Journal of Environmental Sciences》 SCIE EI CAS 2009年第6期758-763,共6页
Four pure cultures were isolated from soil samples potentially contaminated with gasoline compounds either at a construction site near a gas station in Fai Chi Kei,Macao SAR or in the northern parts of China（Beijing,... Four pure cultures were isolated from soil samples potentially contaminated with gasoline compounds either at a construction site near a gas station in Fai Chi Kei,Macao SAR or in the northern parts of China（Beijing,and Hebei and Shandong）.The effects of different concentrations of benzene,toluene,ethylbenzene,and three isomers（ortho-,meta-,and para-） of xylene（BTEX）,total petroleum hydrocarbons（TPH）,and trichloroethylene（TCE）,when they were present in mixtures,on the bio-removal effciencies of microbial isolates were investigated,together with their interactions during the bio-removal process.When the isolates were tested for the BTEX（50-350 mg/L）/TPH（2000 mg/L） mixture,BTEoX in BTEoX/TPH mixture was shown with higher bio-removal effciencies,while BTEmX in BTEmX/TPH mixture was shown with the lowest,regardless of isolates.The TPH in BTEmX/TPH mixture,on the other hand,were generally shown with higher bio-removal effciencies compared to when TPH mixed with BTEoX and BTEpX.When these BTEX mixtures（at 350 mg/L） were present with TCE（5-50 mg/L）,the stimulatory effect of TCE toward BTEoX bio-removal was observed for BTEoX/TCE mixture,while the inhibitory effect of TCE toward BTEmX for BTEmX/TCE mixture.The bio-removal effciency for TPH was shown lower in TPH（2000 mg/L）/TCE（5-50 mg/L） mixtures compared to TPH present alone,implying the inhibitory effect of TCE toward TPH bio-removal.For the mixture of BTEX（417 mg/L）,TPH（2000 mg/L） along with TCE（5- 50 mg/L）,TCE was shown co-metabolically removed more effciently at 15 mg/L,probably utilizing BTEX and/or TPH as primary substrates. 展开更多
关键词 bio-removal benzene, toluene, ethylbenzene, and xylenes （BTEX） co-metabolism trichloroethylene total petroleumhydrocarbons
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Advances in inorganic membranes for xylene isomers separation:Fabrication strategies and mechanistic insights 认领 引用
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作者 Guodong Zhang Songling Xu +3 位作者 Xingye Zeng Yanbin Jiang Rujin Zhou Zhiping Lai 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2026年第4期303-322,共20页
The separation and purification of xylene isomers represent a pivotal process in the petrochemical industry.Compared to ortho-xylene and meta-xylene,para-xylene possesses greater application value.Membrane separation ... The separation and purification of xylene isomers represent a pivotal process in the petrochemical industry.Compared to ortho-xylene and meta-xylene,para-xylene possesses greater application value.Membrane separation technology has shown great potential for application due to its environmental benefits,ease of operation,low energy consumption and excellent selectivity.Notably,attributed to unique pore structures and surface properties,inorganic membrane systems engineered from porous inorganic materials exhibit excellent separation performance for xylene isomers.Through precise molecular discrimination capabilities,this process enables selective recovery of individual isomers,facilitating downstream processing into high-value-added derivatives.This review systematically summarizes recent progress in xylene isomer separation using inorganic membranes.The preparation methods and separation mechanisms of four inorganic membranes were summarized in detail.Furthermore,the two processes involved in the separation of xylene using inorganic membranes were discussed,focusing on solvation diffusion kinetics and the molecular size sieving effect.Subsequently,the challenges currently faced by inorganic membranes were elaborated.Finally,the future development prospects of xylene industrial production were discussed from three perspectives,including membrane material modification strategies,advanced intelligent anti fouling technologies,and comprehensive analysis of mass transfer mechanisms. 展开更多
关键词 Membranes Separation Xylene isomers Pervaporation Vapor permeation
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Trace detection of benzene,toluene and xylene(BTX)by chemiresistive metal oxide-based gas sensors:Recent advances in heterojunction materials design 认领 引用
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作者 Yidan Chen Junzhou Xu +2 位作者 Yanjun Pan Qi Cao Kaiping Yuan 《Chinese Chemical Letters》 SCIE CAS CSCD 2026年第2期72-87,共16页
As the chemical industry expands,the use of benzene,toluene,and xylene(collectively known as BTX)in industrial production has increased greatly.Meanwhile,the toxic nature and potential health hazards of BTX gases cann... As the chemical industry expands,the use of benzene,toluene,and xylene(collectively known as BTX)in industrial production has increased greatly.Meanwhile,the toxic nature and potential health hazards of BTX gases cannot be ignored due to low-concentration leaks underline the critical need for rapid and real-time monitoring of these gases.Chemiresistive metal oxide semiconductor(MOS)-based gas sensors,which are extensively used for gas detection in both industrial settings and everyday life,emerge as one of the optimal solutions for trace BTX detection.These sensors are highly valued for their high sensitivity and low detection limits.Nevertheless,the improvement of selectivity towards specific BTX gases to achieve efficient and precise detection still remains challenging.This review summarizes the chemiresistive MOS-based gas sensors designed for BTX detection,categorizing them based on the components of sensing materials-basically into three groups:single-component,single heterojunction,and multiple heterojunctions gas sensing materials.Further,the review proposes the future application prospects of chemiresistive MOS-based BTX gas sensors,with specific emphasis on their significance in promoting industrial safety and environmental monitoring. 展开更多
关键词 Trace detection Benzene,toluene and xylene(BTX) Chemiresistive Heterojunction Metal oxide semiconductor(Mos)
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Bilayer cascade of WO3nanofibers/Ag@CeO2nanosheets for ppb-level xylene detection under the catalysis-gas sensitivity synergistic mechanism 认领 引用 被引量：1
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作者 Ding Wang Rui-Jie Qin +7 位作者 Jie-Jie Yu Jin-Wu Hu Wen-Hui Zhang Hui Xu Jing-Cheng Xu Qiao-Bo Liao Hui-Jun Li Xu-Hui Wang 《Rare Metals》 SCIE EI CAS CSCD 2025年第7期4868-4880,共13页
The semiconductor gas sensors used for xylene gas detection in real time has been restricted by the inadequate sensitivity and selectivity.Constructing a bilayer cascade sensor with the catalysis-gas sensitivity syner... The semiconductor gas sensors used for xylene gas detection in real time has been restricted by the inadequate sensitivity and selectivity.Constructing a bilayer cascade sensor with the catalysis-gas sensitivity synergistic is considered as an effective solution.Herein,the Ag@CeO2nanosheets are synthesized by heat treating the Ag@Ce-MOF,which synthesized via solvothermal method.The morphological evolution of cerium metalorganic framework(Ce-MOF),regulated by Ag ions,is investigated,and the transformation mechanism is proposed.The bilayer sensors were constructed by using WO3nanofibers,prepared via the electrospinning method,as the sensitive layer and the Ag@CeO2nanosheets as the catalytic layer,respectively.The bilayer sensors exhibit remarkable performance in response to xylene.The response value(Ra/Rg)of WO3/Ag@CeO2sensor to10 ppm xylene gas reaches 32.13 at the operating temperature of 160℃.Additionally,the sensor displays an exceptional response to even trace amounts of xylene,as low as parts per billion(ppb).The catalysis-gas sensitivity synergistic mechanism was elucidated by capturing catalytic intermediates using online mass spectrometry.These findings provide a novel strategy for benzene series(BTEX)sensor and offer a novel approach to prepare twodimensional Ce-MOF and its derived materials with tailored properties. 展开更多
关键词 Ce-MOF nanosheets Gas-sensitive materials Bilayer sensors Xylene detection
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Production of BTX through Catalytic Depolymerization of Lignin 认领 引用 被引量：1
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作者 范明慧 邓淑梅 +1 位作者 王铁军 李全新 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2014年第2期221-226,I0004,共6页
Lignin is the only nature renewable resource which can provide large quantities of aromatic compounds. In the work, transformation of lignin into benzene, toluene, and xylenes （BTX） was investigated over the HZSM-5,... Lignin is the only nature renewable resource which can provide large quantities of aromatic compounds. In the work, transformation of lignin into benzene, toluene, and xylenes （BTX） was investigated over the HZSM-5, HY, and MCM-22 catalysts, and the HZSM-5 catalyst showed the highest carbon yield of BTX. The reaction condition, including temperature, the gas flow rate, and the catalyst/lignin ratio, was also investigated. The carbon yield of BTX reached about 25.3 C-mol% over HZSM-5 catalyst under T=550℃, f（N2）=300 cm^3/min, and catalyst/lignin ratio of 2. 展开更多
关键词 Lignin Benzene Toluene Xylenes Depolymerization
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Indoor and outdoor BTX levels in Barcelona City metropolitan area and Catalan rural areas 认领 引用 被引量：1
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作者 E. Gallego F. X. Roca +1 位作者 X. Guardino M. G. Rosell 《Journal of Environmental Sciences》 SCIE EI CAS 2008年第9期1063-1069,共7页
Five aromatic hydrocarbons (benzene, toluene, and three isomeric xylenes) were monitored in indoor and outdoor air of 7 public buildings and 54 private homes, located in Barcelona City metropolitan area and in several... Five aromatic hydrocarbons (benzene, toluene, and three isomeric xylenes) were monitored in indoor and outdoor air of 7 public buildings and 54 private homes, located in Barcelona City metropolitan area and in several rural areas of Catalonia. The sampling was carried out over four periods: spring-summer and winter of 2000, and summer and winter of 2001. Passive ORSA 5 Dra¨ger samplers were used for benzene, toluene, and xylenes (BTX) adsorption. BTX were extracted with carbon disulphide and analysed using ... 展开更多
关键词 benzene toluene and xylenes （BTX） indoor air outdoor air
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Synthesis of highly active Cu(Ⅰ)-Y(Ⅲ)-Y zeolite and its selective adsorption desulfurization performance in presence of xylene isomers 认领 引用 被引量：1
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作者 Bo-Long Jiang Nan Jiang You-Xin Chang 《Petroleum Science》 SCIE EI CAS CSCD 2021年第1期295-306,共12页
A bimetal-exchanged NaY zeolite(Cu(Ⅰ)-Y(Ⅲ)-Y)with a desirable adsorptive desulfurization(ADS)performance was prepared and characterized by means of X-ray diffraction,specific surface area measurements,X-ray fluoresc... A bimetal-exchanged NaY zeolite(Cu(Ⅰ)-Y(Ⅲ)-Y)with a desirable adsorptive desulfurization(ADS)performance was prepared and characterized by means of X-ray diffraction,specific surface area measurements,X-ray fluorescence spectrometer,X-ray photoelectron spectroscopy,thermal gravity analysis and Fourier transform infrared spectroscopy.The effect of Y(Ⅲ)ions on ADS in the presence of the xylenes was investigated.Results indicated that the ADS performance of Y(Ⅲ)-Y is higher than that of most reported CeY.The Y(Ⅲ)-based Cu(Ⅰ)-Y(Ⅲ)-Y demonstrated the higher breakthrough loading than those of reported Ce(Ⅲ)/Ce(Ⅳ)-based transition metal Y zeolites,showing that Y(Ⅲ)ions play a promoting role in improving the ADS selectivity.For Cu(Ⅰ)-Y(Ⅲ)-Y,a new strong S-M interaction(S stands for sulfur,while M stands for metal)active site was formed,which might be caused by the synergistic effect between Cu(Ⅰ)and Y(Ⅲ).The Cu(Ⅰ)-Y(Ⅲ)-Y,which combined the advantages of Cu(I)-Y and Y(Ⅲ)-Y,is a kind of promising adsorbent.The breakthrough loading decreased in the order of Cu(Ⅰ)-Y(Ⅲ)-Y>Y(Ⅲ)-Y>Cu(Ⅰ)-Y,and the effect of xylene isomers on the sulfur removal was in the order of ortho-xylene>meta-xylene>para-xylene,which exhibited the same trend with the bond order of xylenes. 展开更多
关键词 Desulfurization Yttrium Copper Y zeolite Competitive adsorption Xylenes
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Qualitative analysis of aromatic compounds via 1D TOCSY techniques 认领 引用 被引量：1
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作者 Wenbo Dong Qi Zhao +3 位作者 Jiancheng Zhao Jiarong Zhang Yingxiong Wang Yan Qiao 《Magnetic Resonance Letters》 2024年第1期21-27,共7页
The aromatic compounds,including o-xylene,m-xylene,p-xylene,and ethylbenzene,primarily originate from the catalytic reforming of crude oil,and have a wide variety of applications.However,because of similar physical an... The aromatic compounds,including o-xylene,m-xylene,p-xylene,and ethylbenzene,primarily originate from the catalytic reforming of crude oil,and have a wide variety of applications.However,because of similar physical and chemical properties,these compounds are difficult to be identified by gas chromatography(GC)without standard samples.With the development of modern nuclear magnetic resonance(NMR)techniques,NMR has emerged as a powerful and efficient tool for the rapid analysis of complex and crude mixtures without purification.In this study,the parameters of one-dimensional(1D)total correlation spectroscopy(TOCSY)NMR techniques,including 1D selective gradient TOCSY and 1D chemicalshift-selective filtration(CSSF)with TOCSY,were optimized to obtain comprehensive molecular structure information.The results indicate that the overlapped signals in NMR spectra of nonpolar aromatic compounds(including o-xylene,m-xylene,p-xylene and ethylbenzene),polar aromatic compounds(benzyl alcohol,benzaldehyde,benzoic acid),and aromatic compounds with additional conjugated bonds(styrene)can be resolved in 1D TOCSY.More importantly,full molecular structures can be clearly distinguished by setting appropriate mixing time in 1D TOCSY.This approach simplifies the NMR spectra,provides structural information of entire molecules,and can be applied for the analysis of other structural isomers. 展开更多
关键词 1D TOCSY NMR technologies Xylenes Aromatic compounds Structure information of entire molecular Qualitative analysis
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Benzene alkylation with methanol over phosphate modified hierarchical porous ZSM-5 with tailored acidity 认领 引用 被引量：13
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作者 Jinghui Lyu Hualei Hu +7 位作者 Carolyn Tait Jiayao Rui Caiyi Lou Qingtao Wang Wenwen Han Qunfeng Zhang Zhiyan Pan Xiaonian Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第9期1187-1194,共8页
The acidity and acid distribution of hierarchical porous ZSM-5 were tailored via phosphate modification. The catalytic results showed that both benzene conversion and selectivity of toluene and xylene increased with t... The acidity and acid distribution of hierarchical porous ZSM-5 were tailored via phosphate modification. The catalytic results showed that both benzene conversion and selectivity of toluene and xylene increased with the presence of appropriate amount of phosphorus. Meanwhile, side reactions such as methanol to olefins related with the formation of by-product ethylbenzene formation and isomerization of xylene to meta-xylene were suppressed efficiently. The acid strength and sites amount of Br?nsted acid of the catalyst were crucial for improving benzene conversion and yield of xylene, whereas passivation of external surface acid sites played an important role in breaking thermodynamic equilibrium distribution of xylene isomers. 展开更多
关键词 Hierarchical porous ZSM-5 Phosphate modification Benzene alkylation with methanol Xylene
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Synthesized high-silica hierarchical porous ZSM-5 and optimization of its reaction conditions in benzene alkylation with methanol 认领 引用 被引量：6
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作者 Jiayao Rui Jinghui Lyu +3 位作者 Hualei Hu Qunfeng Zhang Qingtao Wang Xiaonian Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第3期757-761,共5页
In our present work,the high-silica hierarchical porous ZSM-5 with appropriate Br(o|¨)nsted acidity and hierarchical porous structure was synthesized by sol-gel method for continuously catalytic conversion of ben... In our present work,the high-silica hierarchical porous ZSM-5 with appropriate Br(o|¨)nsted acidity and hierarchical porous structure was synthesized by sol-gel method for continuously catalytic conversion of benzene alkylation with methanol to xylene.The effects of temperature,pressure,benzene/methanol molar ratio and weight hour space velocity(WHSV)on the catalytic performance of the catalyst were investigated as well.As a result,the high-silica hierarchical porous ZSM-5 showed great performance as the yield of xylene was up to 41.1%under the optimum reaction conditions(500℃,0.1 MPa,Mbenzene/Mmethanol=1:1.5 and WHSV=4 h 1),while the selectivity to by-product,ethylbenzene,was well suppressed(below 0.1%).In addition,the catalyst structure and properties were characterized by the means of XRD,IR,TPD,SEM,TEM and N_2 physical adsorption technologies. 展开更多
关键词 ZSM-5 Ethylbenzene Xylene Optimization Benzene alkylation
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Occupational Health Risk Assessment of Benzene,Toluene,and Xylene in Shanghai 认领 引用 被引量：7
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作者 WANG Tong Shuai SONG Bo +7 位作者 SUN Qing Hua LIN Yong Xin SUN Yuan SUN Pin JIA Xiao Dong William W.Au MEI Can Hua XIA Zhao Lin 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2021年第4期290-298,共9页
Objective This study was designed to conduct a retrospective and systematic occupational health risk assessment(OHRA)of enterprises that used benzene,toluene,and xylene(BTX)in Shanghai,China.Methods All data for the s... Objective This study was designed to conduct a retrospective and systematic occupational health risk assessment(OHRA)of enterprises that used benzene,toluene,and xylene(BTX)in Shanghai,China.Methods All data for the study were obtained from 1,705 occupational health examination and evaluation reports from 2013 to 2017,and a semiquantitative model following Chinese OHRA guidelines(GBZ/T 298-2017)was applied for the assessment.Results The selected enterprises using BTX were mainly involved in manufacturing of products.Using the exposure level method,health risk levels associated with exposure to BTX were classified as medium,negligible,or low.However,the risk levels associated with benzene and toluene were significantly different according to job types,with gluers and inkers exhibiting greater health risks.For the same job type,the health risk levels assessed using the comprehensive index method were higher than those using the exposure level method.Conclusion Our OHRA reveals that workers who are exposed to BTX still face excessive health risk.Additionally,the risk level varied depending on job categories and exposure to specific chemicals.Therefore,additional control measures recommended by OHRA guidelines are essential to reduce worker exposure levels. 展开更多
关键词 Benzene Toluene Xylene Occupational health risk assessment Exposure level method Comprehensive index method
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Anaerobic biodegradation of benzene series compounds by mixed cultures based on optional electronic acceptors 认领 引用 被引量：11
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作者 HU Zhi-feng DOU Jun-feng +2 位作者 LIU Xiang ZHENG Xi-lai DENG Dong 《Journal of Environmental Sciences》 SCIE EI CAS 2007年第9期1049-1054,共6页
A series of batch experiments were performed using mixed bacterial consortia to investigate biodegradation performance of benzene, toluene, ethylbenzene and three xylene isomers （BTEX） under nitrate, sulfate and fer... A series of batch experiments were performed using mixed bacterial consortia to investigate biodegradation performance of benzene, toluene, ethylbenzene and three xylene isomers （BTEX） under nitrate, sulfate and ferric iron reducing conditions. The results showed that toluene, ethylbenzene, m-xylene and o-xylene could be degraded independently by the mixed cultures coupled to nitrate, sulfate and ferric iron reduction. Under ferric iron reducing conditions the biodegradation of benzene and p-xylene could be occurred only in the presence of other alkylbenzenes. Alkylbenzenes can serve as the primary subs＇rates to stimulate the transformation of benzene and p-xylene under anaerobic conditions. Benzene and p-xylene are more toxic than toluene and ethylbenzene, under the three terminal electron acceptors conditions, the degradation rates decreased with toluene 〉 ethylbenzene 〉 m-xylene 〉 o-xylene〉 benzene 〉 p- xylene. Nitrate was a more favorable electron acceptor compared to sulfate and ferric iron. The ratio between sulfate consumed and the loss of benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene was 4.44, 4.51, 4.42, 4.32, 4.37 and 4.23, respectively; the ratio between nitrate consumed and the loss of these substrates was 7.53, 6.24, 6.49, 7.28, 7.81, 7.61, respectively; the ratio between the consumption of ferric iron and the loss of toluene, ethylbenzene, o-xylene, m-xylene was 17.99, 18.04, 18.07, 17.97, respectively. 展开更多
关键词 benzene, toluene, ethylbenzene and three xylene isomers （BTEX） anaerobic biodegradation nitrate reduction sulfatereduction ferric iron reduction
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Synthesis of high-crystallinity MIL-125 with outstanding xylene isomer separation performance 认领 引用 被引量：2
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作者 Liping Yang Jiacheng Xing +3 位作者 Danhua Yuan Lin Li Yunpeng Xu Zhongmin Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第12期2313-2321,共9页
MIL-125 is a metal-organic framework with great potential for the adsorption and separation of xylene isomers.However,MIL-125 is usually synthesized under anhydrous and anaerobic conditions.In this study,homogeneously... MIL-125 is a metal-organic framework with great potential for the adsorption and separation of xylene isomers.However,MIL-125 is usually synthesized under anhydrous and anaerobic conditions.In this study,homogeneously shaped and highly crystalline MIL-125 was synthesized by introducing water-resistant titanium-containing oligomers into the synthesis process.With the assistance of the novel oligomers,MIL-125 can be synthesized in the presence of water,which meets batch-production requirements.The adsorption separation performance of the obtained highly crystalline MIL-125 was also significantly enhanced.The para-xylene/meta-xylene selectivity can reach 13.5 in mesitylene,which is higher than the selectivity values of most previously reported para-selective adsorbents.The MIL-125 xylene separation performance was verified using both batch adsorption and breakthrough experiments in the liquid phase.In addition,the influence of the solvent effect was evaluated through microcalorimetric experiments,liquid-phase adsorption experiments,and theoretical calculations. 展开更多
关键词 Titanium-containing oligomers MIL-125 Xylene isomers Adsorption separation Solvent effect
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Anaerobic BTEX degradation in soil bioaugmented with mixed consortia under nitrate reducing conditions 认领 引用 被引量：7
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作者 DOU Junfeng LIU Xiang HU Zhifeng 《Journal of Environmental Sciences》 SCIE EI CAS 2008年第5期585-592,共8页
Different concentrations of BTEX, including benzene, toluene, ethylbenzene, and three xylene isomers, were added into soil samples to investigate the anaerobic degradation potential by the augmented BTEX-adapted conso... Different concentrations of BTEX, including benzene, toluene, ethylbenzene, and three xylene isomers, were added into soil samples to investigate the anaerobic degradation potential by the augmented BTEX-adapted consortia under nitrate reducing conditions. All the BTEX substrates could be anaerobically biodegraded to non-detectable levels within 70 d when the initial concentrations were below 100 mg/kg in soil. Toluene was degraded faster than any other BTEX compounds, and the high-to-low order of degradation rates were toluene 〉 ethylbenzene 〉 m-xylene 〉 o-xylene 〉 benzene 〉 p-xylene. Nitrite was accumulated with nitrate reduction, but the accumulation of nitrite had no inhibitory effect on the degradation of BTEX throughout the whole incubation. Indigenous bacteria in the soil could enhance the BTEX biodegradation ability of the enriched mixed bacteria. When the six BTEX compounds were simultaneously present in soil, there was no apparent inhibitory effect on their degradation with lower initial concentrations. Alternatively, benzene, o-xylene, and p-xylene degradation were inhibited with higher initial concentrations of 300 mg/kg. Higher BTEX biodegradation rates were observed in soil samples with the addition of sodium acetate compared to the presence of a single BTEX substrate, and the hypothesis of primary-substrate stimulation or cometabolic enhancement of BTEX biodegradation seems likely. 展开更多
关键词 benzene toluene ethylbenzene xylene BTEX anaerobic biodegradation nitrate reduction soil bioaugmentation cometabolism
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Comparative study of a vitrinite-rich and an inertinite-rich Witbank coal (South Africa) using pyrolysis-gas chromatography 认领 引用 被引量：2
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作者 Ofentse M.Moroeng Vimbai Mhuka +2 位作者 Mathew M.Nindi RJames Roberts Nicola J.Wagner 《International Journal of Coal Science & Technology》 EI CAS 2019年第4期621-632,共12页
This study aims to compare iso-rank vitrinite-rich and inertinite-rich coal samples to understand the impact of coal-forming processes on pyrolysis chemistry.A medium rank C bituminous coal was density-fractionated to... This study aims to compare iso-rank vitrinite-rich and inertinite-rich coal samples to understand the impact of coal-forming processes on pyrolysis chemistry.A medium rank C bituminous coal was density-fractionated to create a vitrinite-rich and an inertinite-rich sub-sample.The vitrinite-rich sample has 83 vol% total vitrinite (mineral-matter-free basis),whereas the inertinite-rich counterpart has 66 vol% total inertinite.The vitrinite-rich sample is dominated by collotelinite and collodetrinite.Fusinite,semifusinite,and inertodetrinite are the main macerals of the inertinite-rich sample.Molecular chemistry was assessed using a pyrolysis gas chromatograph (py-GC) equipped with a thermal desorption unit coupled to a time of flight mass spectrometer (MS) (py-GC/MS) and solid-state nuclear magnetic resonance (13C CP-MAS SS NMR).The pyrolysis products of the coal samples are generally similar,comprised of low and high molecular weight alkanes,alkylbenzenes,alkylphenols,and alkyl-subtituted polycyclic aromatic hydrocarbons,although the vitrinite-rich sample is chemically more diverse.The lack of diversity exhibited by the inertinite-rich sample upon pyrolysis may be interpreted to suggest that major components were heated in their geologic history.Based on the 13C CP-MAS SS NMR analysis,the inertinite-rich sample has a greater fraction of phenolics,reflected in the py-GC/MS results as substituted and unsubstituted derivatives.The greater abundance of phenolics for the inertinite-rich sample may suggest a fire-related origin for the dominant macerals of this sample.The C2-alkylbenzene isomers (p-xylene and o-xylene) were detected in the pyrolysis products for the vitrinite-rich and inertinite-rich samples,though more abundant in the former.The presence of these in both samples likely reflects common source vegetation for the dominant vitrinite and inertinite rnacerals. 展开更多
关键词 Py-TD-GC-TOFMS Main Karoo Basin Pyrolysis products 13C CP-MAS SS NMR Molecular chemistry Phenolics Xylene(C2-alkylbenzene)isomers
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Solid-Liquid Equilibria of Musk Ketone, Musk Xylene and 1,3-Dimethyl-2,4-Dinitro-5-Tert-Butyl Benzene 认领 引用 被引量：2
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作者 曲红梅 白鹏 +1 位作者 杨志才 余国琮 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2004年第2期294-296,共3页
The solid-liquid equilibria of musk ketone + musk xylene, musk xylene +l,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are measured by differential scanning calorimeter (DSC), these systems are proved to be simple eutec... The solid-liquid equilibria of musk ketone + musk xylene, musk xylene +l,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are measured by differential scanning calorimeter (DSC), these systems are proved to be simple eutectics. Moreover the melting points and the fusion enthalpies of musk ketone, musk xylene and 1,3-dimethyl-2,4-dinitro-5-tert-butyl benzene are also measured by the DSC. These solid-liquid equilibrium data and the heats of fusion are reported for the first time. Then UNIFAC model is used to correlate the sofid-liquid equilibrium data. It is shown that the solid-liquid equilibria of musk systems can be predicted by the UNIFAC model. 展开更多
关键词 solid-liquid equilibria differential scanning calorimeter musk ketone musk xylene 1 3-dimethy1-2 4-dinitro-5-tert-butyl benzene
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Selective Hydrogenation of Polycyclic Aromatics to Monocyclic Aromatics over NiMoC/HβCatalysts in a Methane and Hydrogen Environment 认领 引用 被引量：1
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作者 Shen Zhibing Fu Rao +7 位作者 Zhang Shangli Wang Shunmei Zhang Wu Tang Ruiyuan Liang Shengrong Zhang Juntao Yuan Shibao Jiang Haiyan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2023年第2期92-100,共9页
To obtain high yields of monocyclic aromatic hydrocarbons with methyl side chains,such as toluene and xylene,methane(CH4)can be introduced into the hydrocracking of polycyclic aromatic hydrocarbons.CH4can partic... To obtain high yields of monocyclic aromatic hydrocarbons with methyl side chains,such as toluene and xylene,methane(CH4)can be introduced into the hydrocracking of polycyclic aromatic hydrocarbons.CH4can participate in the reaction,supply methyl side chains to the product,and improve product distribution.In this study,the hydrogenation reaction of polycyclic aromatic hydrocarbons over a carbonized NiMo/Hβcatalyst in a CH4and hydrogen(H2)environment was investigated to study the promotional effect of CH4on the hydrocracking of polycyclic aromatics.Under conditions of 3.5 MPa,380℃,volume air velocity of 4 h-1,gas-oil volume ratio of 800,and H2:CH4molar ratio of 1:1,the conversion rate of naphthalene was 99.97%,the liquid phase yield was 93.62%,and the selectivity of BTX were 17.76%,25.17%,and 20.47%,respectively.In comparison to the use of a H2atmosphere,the selectivity of benzene was significantly decreased,whereas the selectivity of toluene and xylene were increased.It was shown that CH4can participate in the hydrocracking of naphthalene and improve the selectivity of toluene and xylene in the liquid product.The carbonized NiMo/Hβcatalyst was characterized by a range of analytical methods(such as X-ray diffraction(XRD),ammonia-temperature-programmed desorption(NH3-TPD),hydrogen-temperature-programmed reduction(H2-TPR),and X-ray photoelectron spectroscopy(XPS)).The results indicated that Ni and Mo carbides were the major species in the carbonized NiMo/Hβcatalyst and were considered to be active sites for the activation of CH4and H2.After loading the metal components,the catalyst displayed prominent weak acidic sites,which may be suitable locations for cracking,alkylation,and other related reactions.Therefore,the carbonized NiMo/Hβcatalyst displayed multiple functions during the hydrocracking of polycyclic aromatic hydrocarbons in a CH4and H2environment.These results could be used to develop a new way to efficiently utilize polycyclic aromatic hydrocarbons and natural gas resources. 展开更多
关键词 methane polycyclic aromatic hydrocarbons hydrocracking NiMoC/Hβ toluene xylene
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可见光响应碳掺杂的光催化剂涂覆于塞流反应器上分解气态芳香化合物(英文) 认领 引用 被引量：1
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作者 Ho‐Hwan CHUN Wan‐Kuen JO 《催化学报》 2013年第6期1256-1261,共6页
A plug‐flow reactor coated with carbon‐doped TiO2 (C‐TiO2 ) powder was investigated for the control of vaporous aromatics (benzene, toluene, ethylbenzene, and o‐xylene (BTEX)) under a range of experimental conditi... A plug‐flow reactor coated with carbon‐doped TiO2 (C‐TiO2 ) powder was investigated for the control of vaporous aromatics (benzene, toluene, ethylbenzene, and o‐xylene (BTEX)) under a range of experimental conditions. The characteristics of the as‐prepared C‐TiO2 and a reference Degussa P25 TiO2 powder were examined using X‐ray diffraction, scanning electron microscopy, diffuse‐reflectance ultraviolet‐visible‐near infrared spectroscopy, and Fourier transform infrared spectroscopy. The experimental conditions for the photocatalytic performance of the as‐prepared C‐TiO2 photocatalyst were controlled using three operational parameters, relative humidity, flow rate, and input concentration. Unlike other target compounds, very little benzene was removed by the C‐TiO2 photocatalyst under visible‐light irradiation. In contrast, the C‐TiO2 exhibited higher removal efficiencies for the other three target compounds (toluene, ethylbenzene, and xylene) compared with those achieved using unmodified TiO2 under visible‐light irradiation. The highest removal efficiency was obtained at a relative humidity value of 45%. Specifically, the toluene removal efficiency determined at a relative humidity of 45% was 78%, whereas it was close to 0%, 7.2%, and 5.5% for relative humidity values of 20%, 70%, and 95%, respectively. In addition, the removal efficiencies for the three target compounds decreased as the flow rate or input concentration increased. These findings indicate that the as‐prepared C‐TiO2 photocatalyst could be used for the removal of toxic vaporous aromatics under optimized operating conditions. 展开更多
关键词 Photocatalysis Vaporous aromatics Benzene Toluene Ethylbenzene o‐Xylene Operational parameter Continuous treatment Indoor air control
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Study on Solution Crystallization of Musk Ketone and Musk Xylene 认领 引用
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作者 曲红梅 周立山 +2 位作者 白鹏 杨志才 余国琮 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2005年第4期548-551,共4页
The ternary phase diagrams of musk ketone, musk xylene and various solvent were obtained by calcu- lations. Moreover, the double saturated lines were found to be curve for the first time. The methods to separate eutec... The ternary phase diagrams of musk ketone, musk xylene and various solvent were obtained by calcu- lations. Moreover, the double saturated lines were found to be curve for the first time. The methods to separate eutectic mixtures of musks by solution crystallization were suggested on the basis of these phase diagrams. A new process was proposed to get musk ketone and musk xylene from the eutectics by adding acetonitrile and heptane in turn, which was verified by experiments. Musk xylene with purity of 97.50% and musk ketone with purity of 98.10% were obtained. 展开更多
关键词 musk ketone musk xylene ternary phase diagram solution crystallization
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