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Photodegradation of xylene isomers:Kinetics,mechanism,secondary pollutant formation potential and health risk evaluation

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Journal of Environmental Sciences 2024年第2期136卷 658-669页

作者： Xiaoyan chen Weikun Zhu Sufen Feng jiangyao chen Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Photodegradation technology has been widely applied in the purification of industrial aromatic hydrocarbons.However,whether this technology efficiently removes the pollutants to prevent secondary pollution and health risk is still unclear.Here,the photodegradation processes of three xylenes were compared under designed reaction atmospheres and light sources.Xe lamp showed poor photodegradation ability toward xylenes,no matter in N_(2) or N_(2)+O_(2)system,while much higher photodegradation performance of xylenes were obtained under ultraviolet(UV)and vacuum ultraviolet(VUV)irradiation,especially in N_(2)+O_(2)+VUV system,where 97.9%of m-xylene,99.0%of o-xylene or 87.5%of p-xylene with the initial concentration of 860 mg/m^(3) was removed within 240 min.The xylenes underwent three processes of photo-isomerization,photodecomposition and photo-oxidation to produce intermediates of aromatics,alkanes and carbonyls.Among them,the photo-isomerization products showed the highest concentration percentage(e.g.,≥50%in o-xylene system),confirming that photo-isomerization reaction was the dominated photodegradation process of xylenes.Moreover,these isomerized products not only contributed about 97%and91%to the formation potential of O3(OFP)and secondary organic aerosols(SOAFP),but also displayed obvious non-carcinogenic risk,although one of photodecomposition product—benzene showed the highest occupational exposure risk.Therefore,the secondary pollution and health risks of photodegradation products of xylenes were non-ignorable,although the OFP,SOAFP and health risks of the generated products reduced at least 4.5 times in comparison with that of the degraded xylenes.The findings are helpful for the appropriate application of this technology in the purification of industrial organic waste gas.

关键词： Isomer aromatics Photodegradation Ozone formation Secondary organic aerosols Health risk

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Underestimated contribution of fugitive emission to VOCs in pharmaceutical industry based on pollution characteristics, odorous activity and health risk assessment

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Journal of Environmental Sciences 2023年第4期126卷 722-733页

作者： Qinhao Lin Zhong Gao Weikun Zhu jiangyao chen Taicheng An Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health Guangzhou Key Laboratory of Environmental Catalysis and Pollution ControlSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Fugitive emission has been becoming an important source of volatile organic compounds(VOCs) in pharmaceutical industry,but the exact contribution of fugitive emission remains incompletely understood.In present study,pollution characteristics,odorous activity and health risk of stack and fugitive emissions of VOCs from four functional units (e.g.,workshop,sewage treatment station,raw material storage and hazardous waste storage) of three representative pharmaceutical factories were investigated.Workshop was the dominant contributor to VOCs of fugitive emission in comparison with other functional units.Extreme high concentration of VOCs from fugitive emission in unsealed workshop (94.87 mg/m^(3))was observed relative to sealed one (1.18 mg/m^(3)),accounting for 31%and 5%of total VOCs,respectively.Fugitive emission of VOCs in the unsealed workshop mainly consisted of nhexane,1-hexene and dichloromethane.Odorous activity indexes and non-cancer hazard ratios of these VOCs from fugitive emission in the unsealed workshop were as high as that from stack exhaust.Furthermore,cancer risk of dichloromethane from fugitive emission and stack exhaust was up to (1.6-1.8)×10^(-5).Odorous activity or health risk index of the VOCs from fugitive emission was up to 13 or 11 times of the corresponding threshold value,posing remarkable health threat on pharmaceutical workers.Our?ndings highlighted the possibly underestimated contribution of fugitive emission on VOCs in the pharmaceutical industry.

关键词： Pharmaceutical industry VOC pollution Fugitive emission Odorous activity index Health risk

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Competing pathways of cresol formation in toluene photooxidation:OH-toluene adducts react with NO_(2) or with O_(2)?

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Journal of Environmental Sciences 2022年第4期34卷 211-220页

作者： Baocong Zhao Yongpeng Ji Dandan Qin Yuemeng Ji jiangyao chen Taicheng An Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthInstitute of Environmental Health and Pollution controlGuangdong University of TechnologyGuangzhou 510006China Key Laboratory of City Cluster Environmental Safety and Green development Guangzhou Key Laboratory of Environmental Catalysis and Pollution ControlSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Methyl-hydroxy-cyclohexadienyl radicals(OTAs)are the key products of the photooxidation of toluene,with implications for the fate of toluene.Hence,we investigated the photooxidation mechanisms and kinetics of three main OTAs(o-OTA,m-OTA,and p-OTA)with NO_(2)using quantum chemical calculations as well as the fate of OTAs under the different concentration ratios of NO_(2)and O_(2).The mechanism results show that the pathway of Habstraction by NO_(2)to anti-HONO(anti-H-abstraction)is more favorable than the syn-Habstraction pathway,because the strong interaction between OTAs and NO_(2)is formed in the transition states of the anti-H-abstraction pathways.The branching ratios of the antiH-abstraction pathways are more than 99%in the temperature range of 216-298 K.The total rate constant of the OTA-NO_(2)reaction is 9.9×10^(-12)cm^(3)/(molecule·sec)at 298 K,which is contributed about 90%by o-OTA+NO_(2),and the main products are o-cresol and anti-HONO.The half-lives of the OTA-NO_(2)reaction in some polluted areas of China are 35 times longer than those of the OTA-O_(2)reaction.In the atmosphere,the NO_(2^(-))and O_(2^(-))initiated reactions of OTAs have the same ability to form cresols as[NO_(2)]is up to 142.1 ppmV,which is impossible to achieve.It implies that under the experimental condition,the[NO_(2)]/[O_(2)]should be controlled to be less than 7.8×10^(-5)to simulate real atmospheric oxidation of toluene.Our results reveal that for the photooxidation of toluene,the yield of cresol is not affected by the concentration of NO_(2)under the atmospheric environment.

关键词： Methyl-hydroxy-cyclohexadienyl radicals Toluene photooxidation Reaction mechanism Kinetics Cresols

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Reactor characterization and primary application of a state of art dual-reactor chamber in the investigation of atmospheric photochemical processes

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Journal of Environmental Sciences 2020年第12期32卷 161-168页

作者： Hao Luo Guiying Li jiangyao chen Yujie Wang Taicheng An Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangzhou Key Laboratory Environmental Catalysis and Pollution ControlSchool of Environmental Science and EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China

Increasing attention has been paid to the air pollution more recently. Smog chamber has been proved as a necessary and effective tool to study atmospheric processes, including photochemical smog and haze formation. A novel smog chamber was designed to study the atmospheric photochemical reaction mechanism of typical volatile organic compounds(VOCs) as well as the aging of aerosols. The smog chamber system includes an enclosure equipped with black lights as the light source, two parallel reactors(2 m^3 of each) with separate control of light source and temperature, with a series of coupled instruments for online monitoring of gas phase and particle phase reactants and products. Chamber characterization, including air source stability, effective light intensity, temperature stability, as well as gas phase and particle phase wall losses, were carried out before further research. The results showed that our smog chamber systems developed by other domestic and international groups. It was also observed that the wall loss of aromatic VOCs varied with different functional groups as well as the isomerism. The results of preliminary simulation experiment from styrene-NO_x demonstrated that the chamber can be well utilized to simulate gas-particle conversion progresses in the atmosphere.

关键词： Smog chamber Dual-reactors Volatile organic compounds Ozone formation Secondary organic aerosol

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Assessing the role of mineral particles in the atmospheric photooxidation of typical carbonyl compound

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Journal of Environmental Sciences 2021年第7期33卷 56-63页

作者： Yongpeng Ji Xingyu chen Yuqi Xiao Yuemeng Ji Weina Zhang Jiaxin Wang jiangyao chen Guiying Li Taicheng An Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthInstitute of Environmental Health and Pollution controlKey Laboratory of City Cluster Environmental Safety and Green developmentSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Mineral particles are ubiquitous in the atmosphere and exhibit an important effect on the photooxidation of volatile organic compounds(VOCs).However,the role of mineral particles in the photochemical oxidation mechanism of VOCs remains unclear.Hence,the photooxi-dation reactions of acrolein(ARL)with OH radical(OH)in the presence and absence of SiO_(2) were investigated by theoretical approach.The gas-phase reaction without SiO_(2) has two distinct pathways(H-abstraction and OH-addition pathways),and carbonyl-H-abstraction is the dominant pathway.In the presence of SiO_(2),the reaction mechanism is changed,i.e.,the dominant pathway from carbonyl-H-abstraction to OH-addition to carbonyl C-atom.The energy barrier of OH-addition to carbonyl C-atom deceases 21.33 kcal/mol when SiO_(2) is added.Carbonyl H-atom of ARL is occupied by SiO_(2) via hydrogen bond,and carbonyl C-atom is ac-tivated by SiO_(2).Hence,the main product changes from H-abstraction product to OH-adduct in the presence of SiO_(2).The OH-adduct exhibits a thermodynamic feasibility to yield HO_(2) radical and carboxylic acid via the subsequent reactions with O_(2),with implications for O 3 formation and surface acidity of mineral particles.

关键词： Photochemical oxidation Mineral particles Acrolein Reaction mechanism

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基于光通量计量法的紫外辐射测定方法建立及其应用研究

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大气与环境光学学报 2024年第2期19卷 175-184页

作者：杨栋森李婉赢陈江耀刘新然郑军南京信息工程大学环境科学与工程学院江苏南京210044 广东工业大学环境健康与污染控制研究院和环境科学与工程学院广东广州510006

近年来,我国大气一次污染颗粒物的浓度逐渐下降,二次生成的气溶胶已经成为了大气颗粒物的主要组成部分。新粒子生成作为二次生成气溶胶的重要来源,本世纪以来受到的关注也越来越高。而气态硫酸作为新粒子生成化学过程中一种极为重要的... 详细信息

近年来,我国大气一次污染颗粒物的浓度逐渐下降,二次生成的气溶胶已经成为了大气颗粒物的主要组成部分。新粒子生成作为二次生成气溶胶的重要来源,本世纪以来受到的关注也越来越高。而气态硫酸作为新粒子生成化学过程中一种极为重要的前体物,由于其浓度极低,检测所需的仪器灵敏度极高,因此如何准确定量气态硫酸是新粒子形成机制研究中最大的难点。现有的气态硫酸的定量方法主要是基于光化学法,利用紫外辐射光解水汽产生OH自由基后与过量的二氧化硫反应最终生成气态硫酸,气态硫酸的浓度由紫外光强与水汽浓度共同决定。其中紫外光强的直接测量存在着较大的不确定性,这主要是由于光强在气态硫酸标定装置的反应腔体中分布不均匀,此外,在实际大气条件下标定时还会受到背景气溶胶的散射、吸收作用的影响。因此,此研究建立并比较了两种分别基于臭氧和氧化亚氮光通量计量法的紫外辐射测定的间接测量方法。结果表明:基于臭氧的间接测量法的主要误差来自于氧气的吸收截面,理论误差>60%,实际实验室的重复实验误差约为12%;基于氧化亚氮的间接测量法的主要误差来自于二级反应速率kn的测量误差、反应产物检测仪器及流量控制装置的不确定性,理论误差<16%,实际实验室的重复实验误差<1%。将基于氧化亚氮的间接测量法应用于外场观测的气态硫酸检测时,在为期半个月每天一次的定标气态硫酸中,气态硫酸的测量误差约为24%,接近或优于国外观测结果,证明基于氧化亚氮的光通量计量法对于紫外辐射的测定方法具有较好的准确性和稳定度,可以有效应用于气态硫酸的定量测量。

关键词：紫外辐射光通量计量法气态硫酸

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信息管理软件自动化测试方法的设计

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自动化仪表 2024年第1期45卷 86-90页

作者：裘雨音张静陈江尧国网浙江省电力有限公司浙江杭州310012 国网浙江省电力有限公司培训中心浙江杭州310015 浙江华云信息科技有限公司浙江杭州310012

为了提高信息管理软件异常识别的准确率,基于深度神经网络设计了一种信息管理软件自动化测试方法。利用Markov链构建信息管理软件任务剖面模型,提取用于信息管理软件自动化测试的任务流。深度优先遍历剖面,融合自动化测试操作行为的变... 详细信息

为了提高信息管理软件异常识别的准确率,基于深度神经网络设计了一种信息管理软件自动化测试方法。利用Markov链构建信息管理软件任务剖面模型,提取用于信息管理软件自动化测试的任务流。深度优先遍历剖面,融合自动化测试操作行为的变化条件、后置条件、操作概率等信息。在此基础上,提取信息管理软件自动测试的任务流。结合已知的软件任务状态转移概率计算极限概率,将重要性显著的用例与参数信息作为优先测试的信息,完成网络训练。建立软件异常自动化识别模型,根据异常识别结果对软件异常位置进行定位,完成信息管理软件自动化测试。测试结果表明,该方法的软件自动化测试结果更准确、自动化效率更高,具有一定的应用价值。

关键词：深度神经网络信息管理软件自动化测试自编码器

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形变退火工艺对2024铝合金性能的影响

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湖南工业大学学报 2024年第4期38卷 98-106页

作者：肖可谋蹇海根陈淼牌君君伍江瑶杨曼湖南工业大学材料与先进制造学院湖南株洲412007 株洲欧科亿数控精密刀具股份有限公司湖南株洲412500 山东省先进铝基材料与技术重点实验室山东滨州262207

采用正交试验法研究了形变量、预回复温度、预回复时间、退火温度和退火时间5个因素对2024铝合金力学性能和腐蚀性能的影响。结果表明:各因素对材料性能的影响显著,其中对力学性能影响最大的因素为退火温度,对腐蚀性能影响最大和最小的... 详细信息

采用正交试验法研究了形变量、预回复温度、预回复时间、退火温度和退火时间5个因素对2024铝合金力学性能和腐蚀性能的影响。结果表明:各因素对材料性能的影响显著,其中对力学性能影响最大的因素为退火温度,对腐蚀性能影响最大和最小的因素分别为形变量和退火时间。通过正交优化得到的最佳形变退火工艺如下:形变量为80%,且在220℃温度下预回复120 min,320℃温度下退火10 min,此工艺下获得的合金具较好综合性能,样品显微硬度、抗拉强度、屈服强度、延伸率、腐蚀深度、R_(p)和I_(corr)分别为74.49 HV、217.17 MPa、185.84 MPa、13.53%、55.4μm、3885.6Ω·cm^(-2)和9.42E-06A·cm^(-2)。

关键词： 2024铝合金形变退火工艺力学性能腐蚀性能

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Synthetic and immunological studies on the OCT4 immunodominant motif antigen-based anti-cancer vaccine

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Cancer Biology & Medicine 2020年第1期17卷 132-141页

作者： Tingting chen Kan Liu jiangyao Xu Tianying Zhan Maixian Liu Li Li Zhiwen Yang Shuping Yuan Wenyi Zou Guimiao Lin Dennis ACarson Christina CNWu Xiaomei Wang Department of Physiology School of Basic Medical SciencesShenzhen University Health Sciences CenterShenzhen UniversityShenzhen 518060China Carson Lab Moores Cancer CenterUCSDLa Jolla 92093CAUSA

Objective:Cancer stem cell is one of the important causes of tumorigenesis as well as a drug target in the treatment of malignant tumor.However,at present,there is no immune vaccine targeting these cells.Octamer-binding transcription factor 4(OCT4),a marker of embryonic stem cells and germ cells,often highly expresses in the early stages of tumorigenesis and is therefore a good candidate for cancer vaccine development.Methods:To identify the optimal carrier and adjuvant combination,we chemically synthesized and linked three different OCT4 epitope antigens to a carrier protein,keyhole limpet hemocyanin(KLH),combined with Toll-like receptor 9 agonist(TLR9).Results:Immunization with OCT4-3+TLR9 produced the strongest immune response in mice.In prevention assays,significant tumor growth inhibition was achieved in BABL/c mice treated with OCT4-3+TLR9(P<0.01).Importantly,the results showed that cytotoxic T lymphocyte activity and the inhibition of tumor growth were enhanced in mice immunized with OCT4-3 combined with TLR9.Meanwhile,multiple cytokines[such as interferon(IFN)-γ(P<0.05),interleukin(IL)-12(P<0.05),IL-2(P<0.01),and IL-6(P<0.05)]promoting cellular immune responses were shown to be greatly enhanced in mice immunized with OCT4-3+TLR9.Moreover,we considered safety considerations in terms of the composition of the vaccines to help facilitate the development of effective next-generation vaccines.Conclusions:Collectively,these experiments demonstrated that combination therapy with TLR9 agonist induced a tumor-specific adaptive immune response,leading to the suppression of primary tumor growth in testis embryonic carcinoma.

关键词： Cancer prevention cancer immunology OCT4 TLR9 agonist

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废水脉冲电解处理节能高效的原因分析

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环境工程学报 2008年第1期2卷 23-26页

作者：陈彬朱又春李彦旭陈江耀广东工业大学环境科学与工程学院广州510090

将脉冲电源和直流电源分别作为废水电解处理的电源，试验探明其对废水电解处理的电能消耗和COD去除率的影响，并分析废水脉冲电解处理节能高效的原因。试验结果表明，脉冲电流相对直流电流能够更加有效减缓电极的极化，降低电极过电位... 详细信息

将脉冲电源和直流电源分别作为废水电解处理的电源，试验探明其对废水电解处理的电能消耗和COD去除率的影响，并分析废水脉冲电解处理节能高效的原因。试验结果表明，脉冲电流相对直流电流能够更加有效减缓电极的极化，降低电极过电位，使电能消耗降低15%-35%；在脉冲电解处理废水过程中电流效率稳定、Fe^2＋能够有效扩散到废水中，使去污效果增强5%-7%。

关键词：脉冲电解电能消耗 COD去除率极化过电位

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