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A Kinetic Study of Ozone and Nitric Oxides in Dielectric Barrier Discharges for O_2/NO_x Mixtures 被引量:5
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作者 孙继忠 Stirner T 王德真 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第2期1227-1238,共12页
A simple model is described to simulate kinetic processes in dielectric barrier dis-charges for O2/NOx mixtures. A threshold of ozone production found experimentally is confirmedby the calculations of this modeling, a... A simple model is described to simulate kinetic processes in dielectric barrier dis-charges for O2/NOx mixtures. A threshold of ozone production found experimentally is confirmedby the calculations of this modeling, and the underiying chemical reaction mechanisms are dis-cussed. It is also found that the effects of diffusion processes in the period of the lifetime of Oatoms are not important to microdischarge channels with a large radius, i.e. larger than l50 μm. 展开更多
关键词 A Kinetic Study of ozone and Nitric oxides in Dielectric Barrier Discharges for O2/nox Mixtures NO
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Simultaneous removal of ethanol, acetaldehyde and nitrogen oxides over V-Pd/γ-Al_2O_3-TiO_2 catalyst
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作者 Zhe Li Jing Wang Kai He Xia An Wei Huang Kechang Xie 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2011年第2期167-172,共6页
V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy ... V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method. X-ray diffraction (XRD), N2 adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS) and catalytic removal of ethanol, acetaldehyde and nitrogen oxides at low temperature (〈300 ?C) were used to assess the properties of the catalysts. The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol, acetaldehyde and nitrogen oxides. The conversions of ethanol, acetaldehyde and nitrogen oxides at 250 ?C were 100%, 74.4% and 98.7%, respectively. V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface, and possessed a larger mole fraction of V4+ species and unique PdO species on the surface, which can be attributed to the strong synergistic effect among palladium, vanadium and the carriers. The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4+ and Pd2+ species on the surface, which might be favorable for the formation of active sites. 展开更多
关键词 V-Pd/γ-Al2o3-TiO2 simultaneous removal ETHANOL ACETALDEHYDE nitrogen oxides
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Protective Effect of Ozone against Hemiscorpius lepturus Envenomation in Mice 被引量:1
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作者 Parvaneh Naserzadeh Farshad Shahi +5 位作者 Delavar Shahbazzadeh Mostafa Ghanei Khadijeh Ashtari Yoones Panahi Mir-Jamal Hosseini Morteza Izadi 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第8期581-590,共10页
Objective Scorpion (Hemiscorpius lepturus) stings are a public health concern in Iran, particularly in south and southwestern regions of Iran. The gold standard for the treatment of a scorpion sting is anti-venom th... Objective Scorpion (Hemiscorpius lepturus) stings are a public health concern in Iran, particularly in south and southwestern regions of Iran. The gold standard for the treatment of a scorpion sting is anti-venom therapy. However, immunotherapy can have serious side effects, such as anaphylactic shock (which can sometimes even lead to death). The aim of the current study was to demonstrate the protective effect of ozone against toxicity induced by Hemiscorpius lepturus (H. lepturus) venom in mice. Methods Eight hours after the injection of ozone to the experimental design groups, the male mice were decapitated and mitochondria were isolated from five different tissues (liver, kidney, heart, brain, and spinal cord) using differential ultracentrifugation. Then, assessment of mitochondrial parameters including mitochondrial reactive oxidative species (ROS) production, mitochondrial membrane potential (MMP), ATP level, and the release of cytochrome c from the mitochondria was performed. Results Our results showed that H. lepturus venom-induced oxidative stress is related to ROS production and MMP collapse, which is correlated with cytochrome c release and ATP depletion, indicating the predisposition to the cell death signaling. Conclusion In general, ozone therapy in moderate dose can be considered as clinically effective for the treatment of H. lepturus sting as a protective and antioxidant agent. 展开更多
关键词 Hemiscorpius lepturus VENOM o3/O2 mixture ozone Oxidative stress
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Equivalent oxide thickness scaling of Al_2O_3/Ge metal-oxide-semiconductor capacitors with ozone post oxidation 被引量:1
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作者 孙家宝 杨周伟 +6 位作者 耿阳 卢红亮 吴汪然 叶向东 张卫 施毅 赵毅 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期561-564,共4页
Aluminum-oxide films deposited as gate dielectrics on germanium (Ge) by atomic layer deposition were post oxidized in an ozone atmosphere. No additional interfacial layer was electron microscopy and X-ray photoelect... Aluminum-oxide films deposited as gate dielectrics on germanium (Ge) by atomic layer deposition were post oxidized in an ozone atmosphere. No additional interfacial layer was electron microscopy and X-ray photoelectron spectroscopy detected by the high-resolution cross-sectional transmission measurements made after the ozone post oxidation (OPO) treatment. Decreases in the equivalent oxide thickness of the OPO-treated Al2O3/Ge MOS capacitors were confirmed. Furthermore, a continuous decrease in the gate leakage current was achieved with increasing OPO treatment time. The results can be attributed to the film quality having been improved by the OPO treatment. 展开更多
关键词 Al2o3 gate dielectric ozone post oxidation equivalent oxide thickness electrical properties
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Influence of Reactive Volatile Organic Compounds on Ozone Production in Houston-Galveston-Brazoria Area
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作者 Samarita Sarker Raghava R. Kommalapati Ziaul Huque 《Journal of Environmental Protection》 2015年第4期399-408,共10页
Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-... Secondary pollutant ozone (O3) formation in a particular area is often influenced by various factors. Source of emissions is one of the factors. In south east Texas, Houston-Galveston-Brazoria (HGB) is a marginal non-attainment area for ozone (O3). A summer episode of May 28 to July 2, 2006 is simulated using Comprehensive Air Quality Model with extensions (CAMx). During this period O3 concentration in HGB often exceeds the National Ambient Air Quality Standards (NAAQS) 0.075 ppm of average 8 hour O3 concentration. HGB area has numerous point sources. Various studies found that some specific volatile organic compounds are very reactive in atmosphere. The objective of this study is to analyze the influence of volatile organic compounds present in point source emissions on the air quality of HGB area. For this purpose ozone sensitivity for HGB area is analyzed by the ratio of hydrogen peroxides (H2O2) to nitric acid (HNO3). HGB area is found NOx limited but reactive VOCs are found to be influential too. From (1-4 June, 2006) maximum O3 concentration was found on weekend, June 3. VOCs such as Acetaldehyde (ALD2), Formaldehyde (FORM) and Alkane (ETHA) showed good correlation with O3 concentrations on that day. In addition, Peroxyacetyl nitrate (PAN) formation was found correlated to higher ozone production. Criteria pollutant Sulfur dioxide (SO2) was found to influence the ALD2 and ETHA concentrations, and thus indirectly influenced O3 production. 展开更多
关键词 Comprehensive Air Quality Model with Extensions (CAMx) nitrogen oxides (nox) ozone (o3) VOLATILE Organic Compound (VOC) Correlation of VOC with o3
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An Experimental Observation of the Thermal Effects and NO Emissions during Dissociation and Oxidation of Ammonia in the Presence of a Bundle of Thermocouples in a Vertical Flow Reactor
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作者 Samuel Ronald Holden Zhezi Zhang +2 位作者 Jian Gao Junzhi Wu Dongke Zhang 《Advances in Chemical Engineering and Science》 2023年第3期250-264,共15页
Ammonia (NH<sub>3</sub>) dissociation and oxidation in a cylindrical quartz reactor has been experimentally studied for various inlet NH<sub>3</sub> concentrations (5%, 10%, and 15%) and reacto... Ammonia (NH<sub>3</sub>) dissociation and oxidation in a cylindrical quartz reactor has been experimentally studied for various inlet NH<sub>3</sub> concentrations (5%, 10%, and 15%) and reactor temperatures between 700 K and 1000 K. The thermal effects during both NH<sub>3</sub> dissociation (endothermic) and oxidation (exothermic) were observed using a bundle of thermocouples positioned along the central axis of the quartz reactor, while the corresponding NH<sub>3</sub> conversions and nitrogen oxides emissions were determined by analysing the gas composition of the reactor exit stream. A stronger endothermic effect, as indicated by a greater temperature drop during NH<sub>3</sub> dissociation, was observed as the NH<sub>3</sub> feed concentration and reactor temperature increased. During NH<sub>3</sub> oxidation, a predominantly greater exothermic effect with increasing NH<sub>3</sub> feed concentration and reactor temperature was also evident;however, it was apparent that NH<sub>3</sub> dissociation occurred near the reactor inlet, preceding the downstream NH<sub>3</sub> and H<sub>2</sub> oxidation. For both NH<sub>3</sub> dissociation and oxidation, NH<sub>3</sub> conversion increased with increasing temperature and decreasing initial NH<sub>3</sub> concentration. Significant levels of NO<sub>X</sub> emissions were observed during NH<sub>3</sub> oxidation, which increased with increasing temperature. From the experimental results, it is speculated that the stainless-steel in the thermocouple bundle may have catalysed NH<sub>3</sub> dissociation and thus changed the reaction chemistry during NH<sub>3</sub> oxidation. 展开更多
关键词 AMMONIA NH3 Dissociation NH3 Oxidation Flow Reactor nitrogen oxides (nox) Thermal Effects
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NO_x与NMHC的变化对O_3生成量的影响 被引量:17
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作者 安俊岭 韩志伟 +3 位作者 王自发 黄美元 陶树旺 程新金 《大气科学》 CSCD 北大核心 1999年第6期753-761,共9页
利用LLA - C 光化学反应机制, 在 NOx 体积分数 φ变化范围很广(1 .75 ~350 .0 ,单位为10 - 9 ,以下同) 的条件下,选择18 种NMHC 与NOx 的体积分数比(2 .0 ~200 .0) 模拟分析在什么条... 利用LLA - C 光化学反应机制, 在 NOx 体积分数 φ变化范围很广(1 .75 ~350 .0 ,单位为10 - 9 ,以下同) 的条件下,选择18 种NMHC 与NOx 的体积分数比(2 .0 ~200 .0) 模拟分析在什么条件下NMHC 的改变对臭氧生成量不大敏感而主要依赖于NOx 的大小,同时给出相应条件下OH 模拟值的变化。结果表明,OH 峰值均出现在φ(NMHC/NOx) ≈8 .0 。所找条件是φ( NOx) ≤50 .0 时要求φ( NMHC/NOx) ≥60 .0 ; φ(NOx) > 50 .0 时需要8 .0 ≤φ(NMHC/NOx) ≤28 .0 。相应O3 生成量的最大误差小于20 % 。该条件正适合我国典型污染城市当前φ(NOx) 水平和φ( NMHC/ NOx) 范围,可用于我国区域尺度空气质量模拟。与实测资料的对比还有待进一步开展。 展开更多
关键词 光化学反应机制 非甲烷烃 氮氧化物 臭氧 生成量
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内燃机排气的光化学反应及对大气中臭氧的影响 被引量:3
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作者 吕刚 解世文 《小型内燃机》 北大核心 2001年第1期30-33,共4页
臭氧 (O3)在大气中含量很少 ,但对人类生活和环境的影响很大。本文首先介绍了臭氧对人类生活和环境的影响 ,而后分别介绍了内燃机排放气体对对流层和平流层臭氧的影响 ,指出发动机排放物(特别是NOX 和HC)对产生光化学烟雾 (对流层臭氧 ... 臭氧 (O3)在大气中含量很少 ,但对人类生活和环境的影响很大。本文首先介绍了臭氧对人类生活和环境的影响 ,而后分别介绍了内燃机排放气体对对流层和平流层臭氧的影响 ,指出发动机排放物(特别是NOX 和HC)对产生光化学烟雾 (对流层臭氧 )有重要影响 ,此外尽管NOX 有破坏平流层臭氧可能性 ,但对其影响程度和效果还有待进一步研究。无论如何 ,减少内燃机尾气排放有利于保持大气臭氧平衡 ,保护人类健康。 展开更多
关键词 臭氧 内燃机 排放物 光化学反应 大气
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臭氧层破坏的起因危害及对策 被引量:2
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作者 夏治强 《城市环境与城市生态》 CAS CSSCI CSCD 1993年第4期37-42,共6页
本文简介了臭氧层的破坏及耗损对生物和人类所造成的危害.描述了氯氟烃(CFC),氮氧化物(NO_x)与臭氧的反应,井详细论述了CFC,NO_x及火山爆发对臭氧层的破坏作用.对有关保护臭氧层的国际公约进行了扼要介绍.提出了防止臭氧耗损应来取的措... 本文简介了臭氧层的破坏及耗损对生物和人类所造成的危害.描述了氯氟烃(CFC),氮氧化物(NO_x)与臭氧的反应,井详细论述了CFC,NO_x及火山爆发对臭氧层的破坏作用.对有关保护臭氧层的国际公约进行了扼要介绍.提出了防止臭氧耗损应来取的措施;执行保护臭氧层的国际公约;寻找CFC替代品; 展开更多
关键词 臭氧耗损 臭氧层 危害 防治
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广州市近地面臭氧时空变化及其生成对前体物的敏感性初步分析 被引量:42
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作者 王宇骏 黄新雨 +4 位作者 裴成磊 张金谱 张艳利 黄祖照 王新明 《安全与环境工程》 CAS 2016年第3期83-88,共6页
近地面臭氧(O_3)污染已日益成为我国城市群地区空气质量难题。基于近年广州国控空气质量观测站点及广州塔的在线观测数据,结合代表性站点典型时间段VOCs的离线采样观测,探讨了广州市O_3浓度的时空变化和污染特征,并初步分析了O_3生成... 近地面臭氧(O_3)污染已日益成为我国城市群地区空气质量难题。基于近年广州国控空气质量观测站点及广州塔的在线观测数据,结合代表性站点典型时间段VOCs的离线采样观测,探讨了广州市O_3浓度的时空变化和污染特征,并初步分析了O_3生成对前体物VOCs和NOx的敏感性。结果表明:2009—2014年广州市近地面O_3浓度年均值波动上升,每年6~10月份O_3浓度最高,一般以10月份污染最严重;O_3浓度日变化呈单峰特征,高值在14:00左右;空间分布上O_3浓度呈现中心城区低、南北郊区高的特征,而2015年1~5月份广州塔观测发现488m高度O_3浓度显著高于168m、118m和6m高度,且其峰值相对延迟1h左右;广州中心城区O_3生成属VOCs敏感型,秋季南部近郊区以VOCs敏感型为主,北部和离中心城区较远的南部郊区属于过渡型;夏季南部远郊属于过渡型但偏NOx敏感型。 展开更多
关键词 近地面臭氧 时空分布 前体物敏感型 挥发性有机物(VOCs) 氮氧化物(nox) 广州市
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臭氧低温氧化烟气脱硝过程中的氮平衡试验研究 被引量:5
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作者 张逸伟 唐海荣 +2 位作者 何勇 朱燕群 王智化 《化工学报》 EI CAS CSCD 北大核心 2022年第4期1732-1742,共11页
臭氧氧化污染物协同脱除技术利用臭氧的强氧化性,将烟气中溶解度较低的NO_(x)、Hg、VOCs等多种污染物氧化为高价态或易溶解的形式,并结合尾部湿法喷淋系统实现污染物的同时脱除。由于其具有温度窗口低、脱硝效率高、反应速率快及改造难... 臭氧氧化污染物协同脱除技术利用臭氧的强氧化性,将烟气中溶解度较低的NO_(x)、Hg、VOCs等多种污染物氧化为高价态或易溶解的形式,并结合尾部湿法喷淋系统实现污染物的同时脱除。由于其具有温度窗口低、脱硝效率高、反应速率快及改造难度小等优点,在工业锅炉、窑炉及非电行业得到广泛应用。但是在此过程中的污染物实际转化路径,尤其是氮氧化物的输入/输出平衡,目前还未有详细的验证试验支撑。因此本文针对典型臭氧氧化脱硝过程,对污染物脱除过程中的氮氧化物输入/输出平衡及氮元素流向进行了分析试验。试验结果表明,气相输入的NO经过臭氧氧化耦合湿法喷淋后逐渐转化为液相中硝酸根和亚硝酸根离子。在不同O_(3)/NO摩尔比下,气相氮元素的减少量均以液相中硝酸根及亚硝酸根的增加量存在,不存在其他含氮形式。同时,吸收浆液中硝酸盐及亚硝酸盐的转化率也与烟气中NO_(x)脱除率相匹配。在NO/SO_(2)同时氧化条件下,调节O_(3)/NO摩尔比,结合湿法喷淋系统可以实现NO_(x)/SO_(2)的协同高效脱除,同时系统满足氮元素输入/输出平衡,为臭氧氧化污染物协同脱除技术的工程应用推广提供了依据。 展开更多
关键词 臭氧氧化 氮平衡 污染 喷淋吸收 氮氧化物 反应
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CeO_2-ZrO_2-La_2O_3-Al_2O_3 composite oxide and its supported palladium catalyst for the treatment of exhaust of natural gas engined vehicles 被引量:4
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作者 Xiaoyu Zhang Enyan,Long +5 位作者 Yile Li Jiaxiu Guo Lijuan Zhang Maochu Gong Minghua Wang Yaoqiang Chen 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2009年第2期139-144,共6页
Composite supports CeO2-ZrO2-Al2O3(CZA) and CeO2-ZrO2-Al2O3-La2O3(CZALa) were prepared by co-precipitation method. Palladium catalysts were prepared by impregnation and their purification ability for CH4, CO and N... Composite supports CeO2-ZrO2-Al2O3(CZA) and CeO2-ZrO2-Al2O3-La2O3(CZALa) were prepared by co-precipitation method. Palladium catalysts were prepared by impregnation and their purification ability for CH4, CO and NOx in the mixture gas simulated the exhaust from natural gas vehicles (NGVs) operated under stoichiometric condition was investigated. The effect of La2O3 on the physicochemical properties of supports and catalysts was characterized by various techniques. The characterizations with X-ray diffraction (XRD) and Raman spectroscopy revealed that the doping of La2O3 restrained effectively the sintering of crystallite particles, maintained the crystallite particles in nanoscale and stabilized the crystal phase after calcination at 1000 ℃. The results of N2-adsorption, H2-temperatnre-programmed reduction (H2-TPR) and oxygen storage capacity (OSC) measurements indicated that La2O3 improved the textural properties, reducibility and OSC of composite supports. Activity testing results showed that the catalysts exhibit excellent activities for the simultaneous removal of methane, CO and NOx in the simulated exhaust gas. The catalysts supported on CZALa showed remarkable thermal stability and catalytic activity for the three pollutants, especially for NOx. The prepared palladium catalysts have high ability to remove NOx, CH4 and CO, and they can be used as excellent catalysts for the purification of exhaust from NGVs operated under stoichiometric condition. The catalysts reported in this work also have significant potential in industrial application because of their high performance and low cost. 展开更多
关键词 Pd catalysts natural gas vehicles exhaust methane oxidation nox conversion CeO2-ZrO2-Al2o3 LA2o3
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大气中过氧乙酰硝酸酯研究综述与展望 被引量:1
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作者 袁峰 汪飞 陈晨 《广东化工》 CAS 2022年第5期68-70,91,共4页
过氧乙酰硝酸酯[CH_(3)C(O)OONO_(2),PAN]是光化学污染产生的一类二次污染物,是大气中氮氧化物的储库,影响着区域光化学污染水平。本文整理了近年来PAN的有关文献,对比分析了国内外不同区域PAN的浓度水平,以及讨论了大气中PAN浓度的影... 过氧乙酰硝酸酯[CH_(3)C(O)OONO_(2),PAN]是光化学污染产生的一类二次污染物,是大气中氮氧化物的储库,影响着区域光化学污染水平。本文整理了近年来PAN的有关文献,对比分析了国内外不同区域PAN的浓度水平,以及讨论了大气中PAN浓度的影响因素。结果发现,城市地区PAN的浓度最高,其次是郊区乡村等偏远地区,海洋极地等清洁地区最低。不同季节PAN的主要影响因素不同,夏季PAN与O_(3)相关性显著,而冬季光化学较弱,PAN与PM_(2.5)相关性显著。 展开更多
关键词 过氧乙酰硝酸酯(PAN) 臭氧(O_(3)) 氮氧化物(NO_(x)) 大气污染物 光化学污染
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NO_x Removal by Oxidation on Alumina Supported Metal Oxide Catalysts Followed by Alkaline Absorption 被引量:1
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作者 Yang Xue Sun Min +1 位作者 Liu Bo Lin Wei 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2019年第3期1-9,共9页
NO oxidation is the key reaction for the oxidative NO x removal process.In this work,the catalytic NO oxidation performance of the Al2O3 supported metal oxide catalysts(M-Al2O3,M=V,Mn,Fe,Co,Ni and Ce)is evaluated.The ... NO oxidation is the key reaction for the oxidative NO x removal process.In this work,the catalytic NO oxidation performance of the Al2O3 supported metal oxide catalysts(M-Al2O3,M=V,Mn,Fe,Co,Ni and Ce)is evaluated.The oxidation product is absorbed by the alkaline solution for NO x removal.The NO oxidation activity increases in the following order:V<<Ce<Ni<Fe<Co<Mn.As the NO oxidation involves the O uptake into the metal oxide lattice and oxidation of the adsorbed NO by the lattice O,the highest activity of Mn is attributed to the appropriate redox potential of Mn,which favors both the O uptake and the NO oxidation steps.For all the M-Al2O3 catalysts,there is an intermediate temperature to achieve maximum NO conversion,which is lower for more efficient M-Al2O3 catalyst.The temperature dependence suggests that the NO oxidation at low temperature is kinetically controlled while it is thermodynamically limited at higher temperature.The NO x removal ratio by the alkaline solution absorption increases with the NO2/NO ratio,with a maximum removal ratio of 80%when the NO2/NO ratio is higher than 3,indicating that a very high NO conversion is unnecessary. 展开更多
关键词 nox REMOVAL NO OXIDATION M-Al2o3 CATALYSTS ALKALINE ABSORPTION
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玻纤池窑废气臭氧脱硝技术探讨 被引量:2
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作者 杜红彩 孙振海 隋荣禄 《玻璃纤维》 CAS 2018年第2期29-33,共5页
依据玻纤池窑烟气的特点,分析了目前烟气脱硝工艺适用性,介绍了一种新的适用于玻纤池窑废气脱硝技术——臭氧氧化脱硝技术,详细论述了臭氧氧化脱硝工艺流程、主要系统组成和技术优势。臭氧氧化脱硝技术具有简单、高效、对工况适应性强... 依据玻纤池窑烟气的特点,分析了目前烟气脱硝工艺适用性,介绍了一种新的适用于玻纤池窑废气脱硝技术——臭氧氧化脱硝技术,详细论述了臭氧氧化脱硝工艺流程、主要系统组成和技术优势。臭氧氧化脱硝技术具有简单、高效、对工况适应性强等特点,在工业窑炉中具有一定的应用前景。 展开更多
关键词 玻纤池窑 废气处理 臭氧 脱硝 氮氧化物
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Activity Enhancement of Pt/Ba/Al_(2)O_(3) Mixed with Mn/Ba/Al_(2)O_(3) for NO_(x) Storage-reduction by Hydrogen
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作者 Jian Hua XIAO Xue Hui LI Sha DENG Fu Rong WANG Le Fu WANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第10期1357-1360,共4页
Abstract: Mn/Ba/Al2O3 catalyst for NO oxidation-storage and Pt/Ba/Al2O3 catalyst mixed with Mn/Ba/Al2O3 for NOx storage-reduction by hydrogen were investigated. The results showed that Mn/Ba/Al2O3 had large nitrogen ... Abstract: Mn/Ba/Al2O3 catalyst for NO oxidation-storage and Pt/Ba/Al2O3 catalyst mixed with Mn/Ba/Al2O3 for NOx storage-reduction by hydrogen were investigated. The results showed that Mn/Ba/Al2O3 had large nitrogen oxides storage capacity (397.9 μmolg^-1) under lean burn condition. When Pt/Ba/Al2O3 catalyst was mixed with Mn/Ba/Al2O3 in equal weight proportion, the NOx conversion increased between 250 ℃ and 500 ℃ under the dynamic lean-rich burn conditions, and the maximum NOx conversion increased from 95.4% to 98.2%. Mn/Ba/Al2O3 has promoted NOx storing in the lean stage and improved NOx reduction efficiency in the rich stage, these might result in higher NOx conversion over the low Pt loading content catalyst. 展开更多
关键词 nitrogen oxides storage-reduction lean burn Pt/Ba/Al2o3 Mn/Ba/Al2o3
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Agroecosystem modeling of reactive nitrogen emissions from U.S.agricultural soils with carbon amendments
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作者 Lina Luo Daniel S.Cohan +2 位作者 Caroline A.Masiello Taras E.Lychuk Xiaodong Gao 《Biochar》 SCIE CAS CSCD 2023年第1期1243-1258,共16页
Fertilizer-intensive agriculture is a leading source of reactive nitrogen(Nr)emissions that damage climate,air quality,and human health.Biochar has long been studied as a soil amendment,but its influence on Nr emissio... Fertilizer-intensive agriculture is a leading source of reactive nitrogen(Nr)emissions that damage climate,air quality,and human health.Biochar has long been studied as a soil amendment,but its influence on Nr emissions remains insufficiently characterized.More recently,the pyrolysis of light hydrocarbons has been suggested as a source of hydrogen fuel,resulting in a solid zero-valent carbon(ZVC)byproduct whose impact on soil emissions has yet to be tested.We incorporate carbon amendment algorithms into an agroecosystem model to simulate emission changes in the year following the application of biochar or ZVC to the US.fertilized soils.Our simulations predicted that the impacts of biochar amendments on Nr emissions would vary widely(−17%to+27%under 5 ton ha^(−1) applications,−38%to+18%under 20 ton ha^(−1) applications)and depend mostly on how nitrification is affected.Low-dose biochar application(5 ton ha^(−1))stimulated emissions of all three nitrogen species in 75%of simulated agricultural areas,while high-dose applications(20 ton ha^(−1))mitigated emissions in 76%of simulated areas.Applying zero-valent carbon at 20 ton ha^(−1) exhibited similar effects on nitrogen emissions as biochar applications at 5 ton ha^(−1).Biochar amendments are most likely to mitigate emissions if applied at high rates in acidic soils(pH<5.84)with low organic carbon(<55.9 kg C ha^(−1))and inorganic nitrogen(<101.5 kg N ha^(−1))content.Our simulations could inform where the application of carbon amendments would most likely mitigate Nr emissions and their associated adverse impacts. 展开更多
关键词 Agricultural nitrogen emissions Nitric oxide(NO) Ammonia(NH_(3)) Nitrous oxide(N_(2)O) BIOCHAR Zerovalent carbon(ZVC)
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2016~2020年上海臭氧高发季光化学污染特征及敏感性分析 被引量:1
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作者 金丹 《环境科学》 EI CAS CSCD 北大核心 2024年第7期3799-3807,共9页
重点臭氧污染区域和城市的臭氧生成敏感性分析是近地面臭氧(O_(3))污染防控的重要依据.基于上海市淀山湖站(郊区)、浦东站(城区)和新联站(工业区站)这3个典型站点2016~2020年5年间O_(3)、VOCs和NO_(x)数据,利用观测模型定量分析5年间臭... 重点臭氧污染区域和城市的臭氧生成敏感性分析是近地面臭氧(O_(3))污染防控的重要依据.基于上海市淀山湖站(郊区)、浦东站(城区)和新联站(工业区站)这3个典型站点2016~2020年5年间O_(3)、VOCs和NO_(x)数据,利用观测模型定量分析5年间臭氧高发季O_(3)与前体物(VOCs和NO_(x))之间的非线性关系.结果表明,2016~2020年间,上海市近地面O_(3)高发月份为4~9月,其中,高峰值出现在6~8月;VOCs体积分数和NO_(2)浓度对浦东站的O_(3)浓度具备较强的指示意义,淀山湖站的O_(3)浓度主要是受区域性环境、气象因素和跨区域传输影响,新联站O_(3)浓度为环境背景浓度与工业区光化学污染的叠加效应.浦东站和淀山湖站处于VOCs控制区,新联站2016~2019年整体处于NO_(x)控制区附近,2020年开始逐步向VOCs控制区转变;浦东站、淀山湖站和新联站的L_(·OH)均为:NO_(x)控制区>协同控制区>VOCs控制区. 展开更多
关键词 臭氧(O_(3)) 挥发性有机物(VOCs) 氮氧化物(NO_(x)) 相对增量反应性(RIR) 光化学反应 臭氧生成敏感性
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基于三维空气质量模型的淄博市臭氧及前体物来源解析 被引量:2
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作者 张馨心 赵秀颖 +4 位作者 黄凌 薛金 卞锦婷 王杨君 李莉 《环境科学》 EI CAS CSCD 北大核心 2023年第12期6576-6585,共10页
基于WRF-CMAQ模型中的ISAM模块对2021年6月淄博市夏季O_(3)及其前体物NO_(2)和VOCs进行来源解析,明确O_(3)及其前体物的来源(区域和源类),并将O_(3)日最大8 h平均值(MDA8)高于(低于)160μg·m^(-3)的时段划分为污染(清洁)时段,对比... 基于WRF-CMAQ模型中的ISAM模块对2021年6月淄博市夏季O_(3)及其前体物NO_(2)和VOCs进行来源解析,明确O_(3)及其前体物的来源(区域和源类),并将O_(3)日最大8 h平均值(MDA8)高于(低于)160μg·m^(-3)的时段划分为污染(清洁)时段,对比了清洁天与污染天的来源差别并选取了典型污染时段进行来源解析和过程分析.结果表明,淄博市夏季NO_(2)主要来自本地排放,贡献率达45.1%,道路移动源(33.8%)和天然源(20.7%)是最主要的本地NO_(2)来源.天然源、溶剂源和石化行业对VOCs的贡献占据主导地位,总贡献达78.5%.MDA8的本地贡献是21.4%,区域外传输(32%)和周边城市(26.8%)影响不可忽略.在本地排放源中,道路移动源、电力行业和建材行业对本地MDA8贡献率在10.9%~18.8%.O_(3)污染天时淄博市MDA8受本地贡献及区域内各城市贡献总和均有所上升.但从淄博市本地源类贡献的变化来看,在不同的污染情况下本地各污染源排放贡献率相近. 展开更多
关键词 臭氧(O_(3)) 挥发性有机物(VOCs) 氮氧化物(NO_(x)) 来源解析 区域多尺度空气质量(CMAQ)模型 华北平原
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郑州市臭氧污染变化特征、气象影响及输送源分析 被引量:55
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作者 王旭东 尹沙沙 +4 位作者 杨健 袁明浩 张瑞芹 李亚松 卢轩 《环境科学》 EI CAS CSCD 北大核心 2021年第2期604-615,共12页
基于环境空气质量和气象在线监测数据,研究了郑州市近地面臭氧(O_(3))污染的年际变化、空间差异及气象影响,并分析了O_(3)传输路径和潜在源区.结果表明,2014~2018年郑州市近地面O_(3)污染超标时间跨度增加,城区站点O_(3)日最大8 h滑动... 基于环境空气质量和气象在线监测数据,研究了郑州市近地面臭氧(O_(3))污染的年际变化、空间差异及气象影响,并分析了O_(3)传输路径和潜在源区.结果表明,2014~2018年郑州市近地面O_(3)污染超标时间跨度增加,城区站点O_(3)日最大8 h滑动平均值(MDA8)第90%分位呈显著上升趋势(P<0.05),增长速率为15.50μg·(m^(3)·a)^(-1);O_(3)月变化呈"M"型,峰值出现在夏季;日变化呈单峰型,峰值出现在15:00~16:00,农村站点O_(3)日峰值浓度(130.94μg·m^(-3))最高;气温(T)>23℃、相对湿度(RH)<65%和风速(WS)为2.0~4.0 m·s^(-1)及风向在东南和东北方向时城市站点易发生高浓度O_(3)污染.各影响因子和O_(3)浓度的多元线性回归分析表明,T和RH是城市和工业站点的主控因子,T和WS是城市交通和郊区站点的主控因子;不同季节后向轨迹聚类分析和O_(3)潜在来源差异明显,春夏季大气传输路径以正南及东北方向近距离慢移速的轨迹为主,秋冬季以西北方向远距离快移速的轨迹为主;夏季高O_(3)浓度主要受本地生成和河北、山东及安徽等地传输影响. 展开更多
关键词 臭氧(O_(3)) 郑州 氮氧化物(NO_(x)) 时空变化 气象影响 潜在源区
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