Abstract ：

挥发性有机污染物(VOCs)作为空气污染物的主要成分之一,也是形成细颗粒物和臭氧的重要前体物.VOCs来源广泛,涉及石油化工、汽车制造、纺织等多个行业.甲苯作为一种典型的VOCs,对人体健康造成严重危害;同时,其具有稳定的芳环结构、不易降解,对其治理迫在眉睫.在众多处理技术中,催化氧化技术可以在低温下将其完全转化成二氧化碳和水,该技术的核心是开发出高活性、高稳定性、抗水抗硫性强的催化剂.因此,本文综述了近几年贵金属催化剂、过渡金属氧化物催化剂、尖晶石型复合氧化物催化剂、钙钛矿型复合氧化物催化剂和金属有机骨架基催化剂等催化氧化甲苯的研究进展,并对其反应机理和动力学进行了讨论,以期帮助开发用于将甲苯完全氧化或者选择性氧化的高效催化材料.

Keyword ：

反应机理 催化剂 催化氧化 挥发性有机物 甲苯

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Abstract ：

基于2021年7-8月份邯郸市主城区环境VOCs的离线手工监测数据,结合同时段的空气质量监测数据和气象资料,分析在不同O3污染情形下前体物VOCs的污染特征和来源,并基于IR值定量计算VOCs参与光化学反应对O3的贡献,同时指出防治O3污染的VOCs优控物种及排放源.结果显示:监测期间VOCs日均浓度为69.2 μg·m-3,OVOCs是占比最高的组分,污染天VOCs浓度有明显升高,且表现出高温、低湿、低风速的气象特征.基于PMF模型的来源解析结果显示,VOCs主要来自工业排放源、燃料燃烧源和机动车尾气源,污染天二次生成源对VOCs的贡献显著提升.监测期间△O3 chem平均值为77.38 μg·m-3,△O3 chem/△O3_obs为61.9％,局地O3生成是O3浓度上升的主要原因.为防控O3污染,应重点监测环境中乙醛、异戊二烯、甲苯/二甲苯、乙烯和丙烯等高活性的VOCs物种,加强对工业排放源、机动车尾气源和燃料燃烧源等人为VOCs排放源的管控.

Keyword ：

臭氧(O3) 来源解析 挥发性有机物(VOCs) VOCs管控策略 邯郸

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Abstract ：

Large petrochemical complex (PC) widely exists in both developing and developed countries, and is expected to have a special photochemical pollution in local scale due to huge VOCs emissions. Here, a typical large-scale PC in North China was selected as the study case, to explore the character, formation and influence of local photochemical pollution regarding PCs based on an improved 0-D chemical model. In the study PC, VOCs-rich character was apparent with THCs level of 90.8 +/- 28.0 ppb and THCs/NOx ratio of similar to 26.2 mol/mol. Severe O-3 pollution was found in warm months with monthly mean MDA1O3 of 67.3-96.0 ppb. Model simulations showed the heavy O-3 pollution in this PC was attributed to high precursors rather than to unfavorable meteorology, and was more sensitive to NOx (with response of 1.42 g/g) than to THCs (with response of 0.12 g/g). The photochemical pollution formation potential of the emission plumes of this PC was very enormous, with production rate of 19.6 ppb h(-1) for O-3, 2.9 ppb h(-1) for HCHO and 1.1 ppb h(-1) for CH3CHO on daytime average, 1-5 greater than in normal urban areas. The higher production rates happened in morning hours, which explained the earlier peak time of observed O-3 in PCs. And about 70% of photochemical pollution (represented by O-3) would be transported to surroundings, leading to the significant photochemical-pollution hazard to the vicinity of PCs.

Keyword ：

Production potential Output contribution Photochemical pollution Petrochemical complex

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Abstract ：

为解决鹤壁市臭氧(O3)污染问题,基于2022年夏季(6～9月)常规污染物及挥发性有机物(VOCs)在线小时分辨率监测数据,采用OFP-PMF源解析-EKMA相结合的方法,进行O3污染及其前体物VOCs来源与减排的污染控制策略分析.结果表明,O3多发生于高温低湿低压条件,芳香烃和含氧挥发性有机物(OVOCs)对臭氧生成潜势(OFP)及VOCs组分贡献较大,是活性和浓度优势物种.源解析结果表明机动车尾气源(25.3%)是鹤壁市VOCs的主要来源,其次是工艺过程源(17.7%)和生物质燃烧源(17.6%).因此,与化石燃料及工业生产相关的排放源是鹤壁市大气VOCs的亟待控制源.在O3污染时期,鹤壁市臭氧生成处于VOCs控制区,基于EKMA的减排模拟结果显示,对VOCs和氮氧化物(NOx)进行协同减排,且VOCs减排75%和NOx减排10%时可以达到国家环境空气质量二级标准.

Keyword ：

VOCs源解析 EKMA曲线 敏感性分析 臭氧(O3) 前体物减排

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Abstract ：

随着国家产业结构的不断调整和工业企业入驻园区刚性要求的不断强化,以高新技术为支柱产业的高新技术产业园区不断增加,为分析涉VOCs高新技术产业对园区环境质量的影响,选取北京市典型高新技术产业园区作为研究案例,采用BCT-7800A PLUS挥发性有机物在线监测系统对园区环境VOCs(共计115种)进行了监测,分析了园区环境VOCs污染水平和臭氧生成潜势,并计算毒性VOCs的危害指数(HI)和终生癌症风险(Risk).利用气相色谱-质谱/氢离子火焰检测器联用(GC-MS/FID)和高效液相色谱(HPLC)的方法检测了园区不同点位的环境VOCs,并对不同点位的环境VOCs污染特征进行了分析.结果表明:① 连续监测期间高新技术产业园区φ(TVOCs)为(72.71±52.51)×10-9,VOCs主要贡献组分为烷烃和OVOCs,占比分别为38.3%和21.8%,主要受燃料燃烧源影响,园区OFP均值为404.13 μg·m-3.② 健康风险评价表明,连续监测期间园区毒性VOCs造成的非致癌风险(HI)均低于1,处于可接受水平;1,2-二氯乙烷平均致癌风险超过安全阈值,表示该物种存在致癌风险,三氯甲烷、1,2-二溴乙烷、1,2-二氯丙烷和苯的均值低于安全阈值,但最高值超过安全阈值,表明这4个物种在特定高排放时段同样存在致癌风险,需要引起重点关注.③ 离线采样检测结果显示,园区不同点位环境φ(TVOCs)的均值为(37.62±11.01)×10-9,4个点位VOCs体积分数大于其他研究中的市区环境监测点位(30.34×10-9).OFP均值为246.38 μg·m-3,5个点位OFP均高于市区监测点位,园区高新技术企业排放的VOCs对环境存在一定的影响.

Keyword ：

污染特征 溶剂使用 健康风险 挥发性有机物 高新技术产业园区

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Abstract ：

挥发性有机化合物(VOCs)和氮氧化物(NOx)是细颗粒物(PM25)和臭氧的重要前驱体,对环境和人类健康造成严重威胁.采用催化技术协同消除VOCs和NOx被认为是一项极具应用潜力的多污染物治理策略,有望实现PM25和臭氧的协同减排.近年来,研究人员对协同催化的催化剂进行了多方面的探索,对协同催化的反应机理也进行了深入研究.综述了目前有关VOCs和NOx协同消除催化剂的研究进展,从钒基催化剂、锰基催化剂和分子筛催化剂的角度,详细论述了不同类型催化剂在协同催化VOCs和NOx方面的最新研究成果.讨论了催化剂的结构和理化性质对催化性能及反应途径的影响.分析了协同催化的反应机理以及各组分对催化反应的影响,深入探讨了 VOCs和NOx协同催化在实际应用中可能存在的问题和不足,对未来多污染协同催化剂的开发提供了建议.

Keyword ：

多污染治理 VOCs 催化剂 反应机理 协同净化 NOx

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Abstract ：

In recent years, the nail industry has been widely popular in China, and the use of nail care products has also significantly increased. Due to its high content of volatile solvents, the released VOCs not only have a negative impact on indoor air quality but also pose a health threat to nail salon workers who are highly exposed to such environments. The objectives of this research were to characterize VOCs emissions from detailed manicure processes and to evaluate the impact on the environment and health risks. Results showed that the VOCs con-centration in the anti-warping treatment process was much higher than that in other manicure steps, at 360.69 mg/m(3), making its contributions of OFP and SOA equally prominent. The trend of concentration contribution was similar to that of OFP, and OVOCs were the most significant contributor to the VOCs components in the whole manicure process. Since organic solvent nail gels were also frequently used in most steps, the main VOCs were methanol, ethanol and ethyl acetate. Aromatics were the component that contributed the most to SOA, and its contributions in all processes were >85 %. Health risk assessments performed in our study indicated that acrolein was the main non-carcinogen, and the carcinogenic risk of this study could be ignored. The results of this study can be used as a basis for controlling VOCs emission and reducing exposure to VOCs in nail salons.

Keyword ：

Emission characteristics Health risk Environmental impact Nail salons Volatile organic compounds(VOCs)

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Abstract ：

Reducing emissions of volatile organic compounds (VOCs) is an integral part of improving the quality of the atmospheric environment. Catalytic oxidation has become an effective means of treating low and medium concentration VOCs exhausts due to its advantages in terms of removal efficiency, energy saving and environmental protection. Due to the unique inherent properties of supported precious metal catalysts, they show good catalytic efficiency in VOCs emission reduction. In this study, the mesoporous Si-WO 3 support was first synthesized by the P123-assisted sol -gel method, and the x Pt/Si-WO 3 catalysts with the actual loadings ( x = 0.19, 0.48, and 0.81 wt%) of Pt nanoparticles (NPs) were then obtained, physicochemical properties of these materials were characterized using a variety of techniques, and their catalytic activities and water resistance for the oxidation of toluene were evaluated. The results showed that Pt NPs with an average particle size of 2.3-3.3 nm were highly dispersed on the mesoporous Si-WO 3 support, and the 0.81Pt/Si-WO 3 sample exhibited the highest catalytic activity for toluene oxidation at a space velocity of 20,000 mL/(g h) ( T 50% = 167 degrees C and T 90% = 180 degrees C; specific reaction rate at 160 degrees C = 8.54 mu mol/(g Pt s), turnover frequency (TOF Pt ) at 160 degrees C = 1.67 x 10 - 3 s - 1 , and apparent activation energy = 45 kJ/mol). The good catalytic performance of 0.81Pt/Si-WO 3 was associated with its large surface area, well dispersed Pt NPs, high adsorbed oxygen species concentration, large toluene adsorption capacity, and strong interaction between Pt NPs and mesoporous Si-WO 3 . The 0.81Pt/Si-WO 3 sample possessed excellent water resistance, and the introduction of 5 vol% or 10 vol% water vapor to the reaction system enhanced toluene oxidation since part of water vapor participated in the oxidation of toluene. In addition, the toluene oxidation pathway might obey the sequence of (adsorbed toluene + adsorbed oxygen species) -* benzyl alcohol -* (benzoic acid and benzaldehyde) -* maleic anhydride -* (carbon dioxide and water).

Keyword ：

Mesoporous structure Water resistance Si-doped tungsten oxide Toluene oxidation Supported platinum catalyst Volatile organic compound

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Industrial flue gas has a great impact on the atmosphere environment and human health, and its emission temperatures are usually below 180 °C, which needs a new technology that can catalyze the removal of the multicomponent VOCs over high-performance catalysts in the presence of ozone. In this work, we prepared the Pt/CeO2 catalysts with different morphologies of Pt particles and investigated their catalytic performance for the ozonization of mixed VOCs (i.e., toluene and chlorobenzene (CB)). Among all of the as-prepared samples, Pt NRs/CeO2 with nanorod-like Pt particles showed excellent catalytic performance for the ozonization of toluene and CB. The T50% (the temperature at VOC conversion = 50%) values for toluene and CB ozonization were 40 and 48 °C at a space velocity of 40,000 mL g-1 h-1, respectively. The results of characterization revealed that the reactive oxygen species involved in the VOC ozonization were mainly the O2- and O22- species, surface oxygen vacancies of CeO2 were the active sites for the conversion of ozone to the reactive oxygen species, and the O2- species was the mainly active oxygen species in the low-temperature VOC oxidation. Furthermore, partial reactive oxygen species reacted with the Ptn+ species to generate more amount of the Pt0 species, and the metallic platinum species was the main active site for the adsorption and activation of toluene and CB. The chemisorbed VOCs at the Pt0 sites reacted with the reactive oxygen species at the interface of Pt and CeO2, resulting in the excellent low-temperature catalytic activity. Compared with the reaction without ozone participation, we find that the participation of ozone can not only decrease the reaction temperature but also reduce the production of toxic byproducts. We are sure that the Pt/CeO2 catalyst is promising in practical application for elimination of the VOCs from industrial flue gas. © 2023 American Chemical Society

Keyword ：

volatile organic compounds supported platinum catalyst ozonization reactive oxygen species VOC mixture removal

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A major challenge in utilizing metal-organic frameworks (MOFs) for volatile organic compound (VOC) capture was their inclination for strong adsorption, which consequently impeded desorption and elevated energy demand. To overcome this challenge, the construction of HKUST-1@Cu nanofibers (HK@Cu-NF) with thermal conductive adsorption sites was proposed to synchronous enhance toluene adsorption and desorption efficiency for VOCs capture. In this work, Cu-based HKUST-1 was designed to grow on Cu nanofibers, and formed uniform coverage MOF layer with tight connection via homologous Cu self-transformation growth strategy. The synthesized composite was proved to maintain high surface area (1473 m(2)/g) and generate abundant unsaturated Cu sites on its nanointerface based from the thermally conductive Cu nanofibers. This unique connection structure endowed these adsorption sites with high affinity towards toluene and high thermal conductivity as well, and finally formed thermal conductive adsorption sites. As a result, HK@Cu-NF composite (80 % loading of HKUST-1) exhibited 1.9 times higher of toluene adsorption capacity at P/P-0 = 0.002 and >3 times higher of thermal diffusivity than pure HKUST-1. Furthermore, it achieved enhancement in both adsorption and desorption efficiency for toluene, which reached 4.8 and 6.9 times of pure HKUST-1. Therefore, construction of thermal conductive adsorption sites successfully improved the adsorption efficiency and regeneration efficiency for VOCs capture, and realized the low energy VOCs desorption process.

Keyword ：

Thermal conductive adsorption sites MOF composite nanofiber Toluene adsorption/desorption Homologous Cu self -transformation growth

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