VOC

VOC
  • 文章类型: Journal Article
    在这项研究中,探索了一种共催化途径来增强挥发性有机化合物(VOC)的光臭氧催化降解。将NiCo2O4负载到CeO2纳米颗粒的表面上以产生复合催化剂(10%NiCo2O4/CeO2)。NiCo2O4在CeO2上的集成增强了催化剂与甲苯之间的相互作用,代表性的VOC,导致甲苯吸附显着增加,而比表面积没有相应增加。这种集成还改善了电荷载体的利用和臭氧到O2的转化。在可见光照射下,H2O在10%NiCo2O4/CeO2表面积累电荷载流子,促进臭氧利用和甲苯吸附。NiCo2O4负载的另一个好处是其提高太阳能转换效率的能力。因此,与CeO2相比,10%NiCo2O4/CeO2的甲苯去除和矿化效率分别提高了182%和309%,与NiCo2O4相比分别提高了201%和357%。总的来说,这项研究证明了一种新型的助催化剂设计策略,用于增强VOCs的光臭氧催化降解。
    In this study, a co-catalytic route was explored to enhance the photo-ozone catalytic degradation of volatile organic compounds (VOCs). NiCo2O4 was loaded onto the surface of CeO2 nanoparticles to create a composite catalyst (10%NiCo2O4/CeO2). The integration of NiCo2O4 onto CeO2 enhanced the interaction between the catalyst and toluene, a representative VOC, resulting in significantly increased toluene adsorption without a corresponding increase in specific surface area. This integration also improved the utilization of charge carriers and conversion of ozone to O2-. Under visible light irradiation, H2O accumulated charge carriers at 10%NiCo2O4/CeO2\'s surface, facilitating both ozone utilization and toluene adsorption. Another benefit of NiCo2O4 loading was its ability to enhance the conversion efficiency of solar energy. Consequently, the toluene removal and mineralization efficiencies of 10%NiCo2O4/CeO2 were enhanced by 182% and 309% compared to CeO2, and by 201% and 357% compared to NiCo2O4, respectively. Overall, this study demonstrated a novel co-catalyst design strategy for enhancing the photo-ozone catalytic degradation of VOCs.
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  • 文章类型: Journal Article
    一种有前途的污染控制技术是冷等离子体驱动的化学处理。等离子体是在接近大气压-温度的反应器内的脉冲电气体放电。该系统由非常短的高压脉冲的连续流供电。待处理的废气流过反应器。应用的方法涉及开发强大的冷等离子体系统,工业应用和测量技术。在许多工业现场进行了系统测试,涉及控制空气中的VOC(挥发性有机化合物)和气味。电气,用最先进的方法收集化学和气味测量数据。为了解释测试数据,开发了脉冲等离子体化学的整体反应动力学的近似解。它涉及到兰伯特函数,为方便起见,一个简单的近似。后者表明,去除量,在很好的近似中,是单个变量的函数。该变量是电等离子体功率除以气流除以输入浓度。在结果部分中,我们表明,在某些情况下,可以在可接受的能量需求下去除高达99%的挥发性污染。在最后部分中,我们将通过实施(亚)纳秒脉冲等离子体和固态高压技术以及与催化剂技术的集成来探讨未来的效率提高。
    A promising pollution control technology is cold plasma driven chemical processing. The plasma is a pulsed electric gas discharge inside a near atmospheric-pressure-temperature reactor. The system is energized by a continuous stream of very short high-voltage pulses. The exhaust gas to be treated flows through the reactor. The methods applied involve the development of robust cold plasma systems, industrial applications and measuring technologies. Tests of the systems were performed at many industrial sites and involved control of airborne VOC (volatile organic compound) and odor. Electrical, chemical and odor measuring data were collected with state-of-the-art methods. To explain the test data an approximate solution of global reaction kinetics of pulsed plasma chemistry was developed. It involves the Lambert function and, for convenience, a simple approximation of it. The latter shows that the amount of removal, in good approximation, is a function of a single variable. This variable is electric plasma power divided by gas flow divided by input concentration. In the results sections we show that in some cases up to 99% of volatile pollution can be removed at an acceptable energy requirement. In the final sections we look into future efficiency enhancements by implementation of (sub)nanosecond pulsed plasma and solid state high-voltage technology and by integration with catalyst technology.
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  • 文章类型: Journal Article
    甲醛的室温催化氧化(HCHO)因其高效,便利性,和环境友好。在这里,镍-铁层状双氢氧化物(NiFeLDH)纳米片在镍箔(NF)上使用简单的一步水热法原位合成,然后通过NaBH4还原沉积超低含量(0.069wt%)的Pt纳米颗粒。所得的三维(3D)分层Pt/NiFe-NF催化剂在室温下表现出甲醛完全分解为二氧化碳(CO2)的特殊活性(在1小时内转化率约95%),以及显着的循环稳定性。Pt/NiFe-NF的3D多孔结构为气体分子的扩散提供了快速的传输通道,使活性催化剂表面更容易接近。此外,NiFeLDH中丰富的羟基用作HCHO分子的吸附中心,以形成二甲醛(DOM)和甲酸酯中间体。此外,NiFeLDH与Pt之间的电子相互作用增强了O2在Pt表面的吸附和活化,导致中间体完全分解为无毒产品。这项工作为设计和制备具有表面富含羟基的Pt基3D分层催化剂提供了新的见解,可有效去除室内HCHO。
    Room-temperature catalytic oxidation of formaldehyde (HCHO) has been extensively investigated due to its high efficiency, convenience, and environmental friendliness. Herein, nickel-iron layered double hydroxide (NiFe LDH) nanosheets were synthesized in-situ on a nickel foil (NF) using a facile one-step hydrothermal method, followed by the deposition of ultra-low content (0.069 wt%) of Pt nanoparticles through NaBH4 reduction. The resulting three-dimensional (3D) hierarchical Pt/NiFe-NF catalyst exhibited exceptional activity for the complete decomposition of formaldehyde to carbon dioxide (CO2) at room temperature (∼95 % conversion within 1 h), as well as remarkable cycling stability. The 3D porous structure of Pt/NiFe-NF provides fast transport channels for the diffusion of gas molecules, making the active catalyst surfaces more accessible. Moreover, abundant hydroxyl groups in NiFe LDH serve as adsorption centers for HCHO molecules to form dioxymethylene (DOM) and formate intermediates. Furthermore, electronic interactions between NiFe LDH and Pt enhance the adsorption and activation of O2 on Pt surfaces, leading to the complete decomposition of intermediates into non-toxic products. This work presents new insights into the design and preparation of Pt-based 3D hierarchical catalysts with surface-rich hydroxyl groups for the efficient removal of indoor HCHO.
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  • 文章类型: Journal Article
    不同结构的短链烃的排放控制对石化行业至关重要。在这里,三种含二碳(C2)的碳氢化合物,乙烷,乙烯,和乙炔,选择作为污染物,研究了生物滴滤过滤器中碳氢化合物的化学结构对去除性能和微生物响应的影响。结果表明,C2烃的去除效率(RE)遵循乙炔>乙烷>乙烯的顺序。当入口负载速率为30g/(m3·h),空床停留时间为60s时,乙烷的RE,乙烯,乙炔为57±4.0%,49±1.0%,84±2.7%,分别。高水溶性导致C2烃的高去除率,而低表面张力增强了C2烃的去除。此外,微生物群落,酶活性,微生物的细胞外特性也导致了C2烃去除的差异。这些结果可为有效控制轻烃排放提供参考。
    The control of emissions of short-chain hydrocarbons with different structures is critical for the petrochemical industry. Herein, three two-carbon-containing (C2) hydrocarbons, ethane, ethylene, and acetylene, were chosen as pollutants to study the effects of chemical structure of hydrocarbons on removal performance and microbial responses in biotrickling filters. Results showed that the removal efficiency (RE) of C2 hydrocarbons followed the sequence of acetylene > ethane > ethylene. When the inlet loading rate was 30 g/(m3·h) and the empty bed residence time was 60 s, the RE of ethane, ethylene, and acetylene was 57 ± 4.0 %, 49 ± 1.0 %, and 84 ± 2.7 %, respectively. The high water solubility resulted in the high removal of C2 hydrocarbons, while a low surface tension enhanced the removal of C2 hydrocarbons. Additionally, the microbial community, enzyme activity, and extracellular properties of microorganisms also contributed to the difference in C2 hydrocarbon removal. These results could be referred for the effective control of light hydrocarbon emissions.
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  • 文章类型: Journal Article
    将废物资源转化为多孔碳用于污染物捕获是实现“用废物处理废物”的环境目标的有效策略。软木由于其有序的蜂窝状单元结构和层状组成分布而成为多孔碳的理想前体。在这里,通过尿素辅助水热碳化和化学活化两个步骤制备了N掺杂的多孔碳(PC),以减轻挥发性有机化合物(VOC)的污染。结果表明,所获得的PC4-800表现出显著的吸附特征,包括高总孔体积(0.97cm3/g)和比表面积(1864.89m2/g),以及丰富的含N官能团。优异的孔结构主要是由于K2CO3和含N官能团反应产生的气体对碳基质的腐蚀。吸附结果表明,PC4-800具有出色的甲苯吸附能力(867.03mg/g),优于以前报道的大多数吸附剂。N掺杂的PC中存在大量孔,孔宽度为1.71-2.28nm,是甲苯分子动力学直径的3到4倍,在吸收过程中起着至关重要的作用。此外,通过高斯模拟的DFT计算,验证了N官能团对甲苯吸附过程的促进作用,其中N-6在N掺杂的PCs表面产生π电子富集位点,利用苯环促进π-π在甲苯中的分散。本研究提供了一种将废软木转化为高效吸附剂去除VOCs的新策略。
    Converting waste resources into porous carbon for pollutants capture is an effective strategy to achieve the environmental goal of \"treating waste with waste\". Cork is an ideal precursor of porous carbons due to its ordered honeycomb-like cell structure and layered composition distribution. Herein, N-doped porous carbons (PCs) were prepared via two steps of urea-assisted hydrothermal carbonization and chemical activation to mitigate volatile organic compounds (VOCs) pollution. Results indicated that the obtained PC4-800 exhibited remarkable features for adsorption including high total pore volume (0.97 cm3/g) and specific surface area (1864.89 m2/g), as well as abundant N-containing functional groups. The excellent pore structure was primarily owing to the corrosion of the carbon matrix by the gas produced from the reaction of K2CO3 and N-containing functional groups. The adsorption results showed that the PC4-800 have an outstanding toluene adsorption capacity (867.03 mg/g) that outperforming majority of adsorbents previously reported. There are substantial pores in N-doped PCs with a pore width of 1.71-2.28 nm, which is 3 to 4 times the molecular dynamic diameter of toluene, and plays a crucial role in the absorption process. Moreover, the promotional influence of N-functional groups on the toluene adsorption process was verified through DFT calculation by Gaussian imitating, where N-6 generated π-electron enrichment sites on the surface of N-doped PCs, facilitating π-π dispersion with the benzene ring in toluene. This study provides a new strategy to convert waste cork into high-performance adsorbents for VOCs removal.
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  • 文章类型: Journal Article
    目的:本研究旨在对现有文献进行全面总结,并对前路可控前移融合术(ACAF)和后路椎管成形术(LP)治疗颈椎后纵韧带多节段骨化症(OPLL)的临床疗效进行系统评价。
    方法:我们对数据库进行了电子搜索,包括PubMed,Embase,科克伦图书馆,和CNKI,从初始数据库开始到2023年3月。我们分析了各种参数,包括人口统计数据,操作时间,术中失血,颈椎曲度,日本骨科协会(JOA)评分,视觉模拟量表(VAS)评分,术后并发症。两名独立审稿人筛选了这些文献,提取的数据,并评估纳入研究的偏倚风险。采用RevMan5.4软件进行Meta分析。
    结果:我们的评估包括7项研究,共涉及467名患者。患者队列分为两组:A组(ACAF)包括226名患者,而B组(LP)包括241例患者。总的来说,我们的统计分析显示两组在术中出血量方面有显著差异(P<0.05),手术时间,JOA得分,JOA评分改善率,术后VAS评分,术后颈椎曲度,以及某些术后并发症的发生率(C5神经根麻痹,吞咽困难,和轴向症状)。然而,两组术后脑脊液漏发生率及术后总并发症比较,差异无统计学意义(P>0.05)。
    结论:这项研究的结果表明,在多级子宫颈OPLL的治疗中,与LP相比,ACAF产生更好的结果。具体来说,ACAF改善术后神经功能,减少术后疼痛,降低术中失血量,改善术后颈椎曲度,并降低C5神经根麻痹和术后轴性症状的发生率。尽管如此,ACAF与更长的手术时间和更高的术后吞咽困难的发生率相关。尽管术后并发症的总体发生率相似。重要的是要注意,由于样本量有限和纳入研究的质量参差不齐,这些结论应谨慎解释。涉及更大的进一步研究,需要高质量的研究来验证这些发现.
    This study aims to provide a comprehensive summary of the existing literature and conduct a systematic evaluation of the clinical outcomes associated with anterior controllable antedisplacement and fusion (ACAF) and posterior laminoplasty (LP) for the treatment of multisegment ossification of the cervical posterior longitudinal ligament (OPLL).
    We conducted an electronic search of databases, including PubMed, Embase, Cochrane Library, and CNKI, from the inception of the initial database to March 2023. We analyzed various parameters, including demographic data, operation time, intraoperative blood loss, cervical curvature, Japanese Orthopaedic Association (JOA) scores, Visual Analog Scale (VAS) scores, and postoperative complications. Two independent reviewers screened the literature, extracted data, and assessed the risk of bias in the included studies. Meta-analysis was performed using RevMan 5.4 software.
    Our evaluation encompassed 7 studies involving a total of 467 patients. The patient cohort was divided into 2 groups: Group A (ACAF) comprised 226 patients, while Group B (LP) comprised 241 patients. Overall, our statistical analysis revealed significant differences between the 2 groups (P < 0.05) in terms of intraoperative blood loss, operative time, JOA score, JOA score improvement rate, postoperative VAS score, postoperative cervical curvature, and the incidence of certain postoperative complications (C5 nerve root paralysis, dysphagia, and axial symptoms). However, there was no statistically significant difference in the incidence of postoperative cerebrospinal fluid leakage and postoperative total complications between the 2 groups (P > 0.05).
    The findings of this study suggest that, in the treatment of multilevel cervical OPLL, ACAF yields superior outcomes compared to LP. Specifically, ACAF improves postoperative neurologic function, reduces postoperative pain, lowers intraoperative blood loss, improves postoperative cervical curvature, and decreases the incidence of C5 nerve root paralysis and postoperative axial symptoms. Nonetheless, ACAF is associated with longer operative times and a higher incidence of postoperative dysphagia, though the overall incidence of postoperative complications is similar. It is important to note that these conclusions should be interpreted cautiously due to the limited sample size and the variable quality of the included studies. Further research involving larger, high-quality studies is warranted to validate these findings.
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  • 文章类型: Journal Article
    Although 2D MoS2 alone shows excellent gas-sensing performance, it is prone to stacking when used as the sensitive layer, resulting in insufficient contact with the target gas and lower sensitivity. To solve this, a 2D-MoS2/1D-CuPc heterojunction was prepared with different weight ratios of MoS2 nanosheets to CuPc micro-nanowires, and its room-temperature gas-sensing properties were studied. The response of the 2D-MoS2/1D-CuPc heterojunction to a target gas was related to the weight ratio of MoS2 to CuPc. When the weight ratio of MoS2 to CuPc was 20:7 (7-CM), the gas sensitivity of MoS2/CuPc composites was the best. Compared with the pure MoS2 sensor, the responses of 7-CM to 1000 ppm formaldehyde (CH2O), acetone (C3H6O), ethanol (C2H6O), and 98% RH increased by 122.7, 734.6, 1639.8, and 440.5, respectively. The response of the heterojunction toward C2H6O was twice that of C3H6O and 13 times that of CH2O. In addition, the response time of all sensors was less than 60 s, and the recovery time was less than 10 s. These results provide an experimental reference for the development of high-performance MoS2-based gas sensors.
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  • 文章类型: Journal Article
    苍术在东亚地区分布广泛,从阿穆尔到中国中南部。仙人掌的根茎常用于中药中,然而,不同地区的产品质量各不相同,具有不同的地球化学特征。
    本研究旨在通过使用基于GC-MS/MS的靶向代谢组学方法对挥发性有机化合物(VOCs)进行定量来鉴定来自不同地区的兰花菜的化学型,并筛选化学标记。
    柳叶草分布在湖北,安徽,陕西,河南省西部的一个地区被归类为湖北化学型(HBA)。HBA的特征是β-eudesmol和hinesol的含量高,而苍术素和atractylon的含量较低。相比之下,江苏茅山化学型(MA),山东,山西,河北,内蒙古,和其他北部地区,表现出高水平的苍术素和atractylon。共检测并鉴定了15类VOCs代谢物,揭示了萜类化合物轮廓的显著差异,杂环化合物,酯,不同地区之间的酮。多变量统计表明,6个化合物和455个代谢物可以作为区分南方获得的A.lancea的候选标记,北方,和茅山地区。
    这种综合分析提供了选定的A.lancea的化学指纹。我们的研究结果突出了代谢物分析与化学计量学相结合的潜力,可用于鉴定A.lancea的地理起源。
    UNASSIGNED: Atractylodes lancea is widely distributed in East Asia, ranging from Amur to south-central China. The rhizome of A. lancea is commonly used in traditional Chinese medicine, however, the quality of products varies across different regions with different geochemical characteristics.
    UNASSIGNED: This study aimed to identify the chemotypes of A. lancea from different areas and screen for chemical markers by quantifying volatile organic compounds (VOCs) using a targeted metabolomics approach based on GC-MS/MS.
    UNASSIGNED: The A. lancea distributed in Hubei, Anhui, Shaanxi, and a region west of Henan province was classified as the Hubei Chemotype (HBA). HBA is characterized by high content of β-eudesmol and hinesol with lower levels of atractylodin and atractylon. In contrast, the Maoshan Chemotype (MA) from Jiangsu, Shandong, Shanxi, Hebei, Inner Mongolia, and other northern regions, exhibited high levels of atractylodin and atractylon. A total of 15 categories of VOCs metabolites were detected and identified, revealing significant differences in the profiles of terpenoid, heterocyclic compound, ester, and ketone among different areas. Multivariate statistics indicated that 6 compounds and 455 metabolites could serve as candidate markers for differentiating A. lancea obtained from the southern, northern, and Maoshan areas.
    UNASSIGNED: This comprehensive analysis provides a chemical fingerprint of selected A. lancea. Our results highlight the potential of metabolite profiling combined with chemometrics for authenticating the geographical origin of A. lancea.
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  • 文章类型: Journal Article
    作为一种广泛存在的室内空气污染物,挥发性有机化合物(VOC)造成各种不良健康影响,尤其是对肝脏的损害,这已成为公众日益关注的问题。然而,当前的毒性数据本质上仅限于单一或主要的VOC物种。关于毒性作用的知识有限,真正的室内VOC引起的肝损伤的生物标志物和潜在机制。在这里,建立了室内相关VOC暴露模型来评估肝脏不良结局.机器学习和多组学方法,包括肝脏脂质组学,血清脂质组学和肝脏转录组学,被用来揭示肝脏损伤的特征,血清脂质生物标志物,涉及VOC暴露刺激的机制。结果表明,室内相关性VOC导致肝脏脂质代谢异常,主要表现为三酰甘油(TG)及其前体物质二酰甘油(DG)的减少,这可能导致肝脏不良后果的发生。在血清脂质生物标志物方面,使用机器学习发现血清中的五种脂质生物标志物,以反映VOC引起的肝脏脂质紊乱。多组学方法表明,上调的Dgkq干扰了DG和磷脂酸(PA)的相互转化,导致TG下调。深入分析发现VOC下调FoxO转录因子,有助于Dgkq的上调。因此,这项研究可以为了解室内相关VOC暴露模型VOC暴露引起的肝损伤提供有价值的见解,从多组学的角度分析。
    As a widespread indoor air pollutant, volatile organic compound (VOC) caused various adverse health effects, especial the damage to liver, which has become a growing public concern. However, the current toxic data are intrinsically restricted in the single or major VOC species. Limited knowledge is available regarding toxic effects, biomarkers and underlying mechanisms of real indoor VOC-caused liver damage. Herein, an indoor relevant VOC exposure model was established to evaluate the hepatic adverse outcomes. Machine learning and multi-omics approaches, including liver lipidomic, serum lipidomic and liver transcriptomic, were utilized to uncover the characteristics of liver damage, serum lipid biomarkers, and involved mechanism stimulated by VOC exposure. The result showed that indoor relevant VOC led to the abnormal hepatic lipid metabolism, mainly manifested as a decrease in triacylglycerol (TG) and its precursor substance diacylglycerol (DG), which could be contributed to the occurrence of hepatic adverse outcomes. In terms of serum lipid biomarkers, five lipid biomarkers in serum were uncovered using machine learning to reflect the hepatic lipid disorders induced by VOC. Multi-omics approaches revealed that the upregulated Dgkq disturbed the interconversion of DG and phosphatidic acid (PA), leading to a TG downregulation. The in-depth analysis revealed that VOC down-regulated FoxO transcription factor, contributing to the upregulation of Dgkq. Hence, this study can provide valuable insights into the understanding of liver damage caused by indoor relevant VOC exposure model VOC exposure, from the perspective of multi-omics analysis.
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  • 文章类型: Journal Article
    沙门氏菌是禽类及其产品中最常见的食源性致病菌之一。其基于挥发性有机化合物(VOC)的快速检测已被广泛接受。然而,早期(48小时)沙门氏菌污染鸡的VOCs变化仍不确定。利用顶空-SPME-气相色谱-质谱(HS-SPME-GC-MS)和顶空-气相色谱-离子迁移谱(HS-GC-IMS)对鸡肉被沙门氏菌污染后的挥发性有机化合物及其变化进行了鉴定。进行化学计量学和KEGG富集分析以鉴定VOC标志物及其潜在的代谢途径。使用HS-GC-IMS共检测到64种挥发性化合物,基于主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA),显示出比HS-SPME-GC-MS(45种挥发性化合物)更好的区分性。脂肪酸降解是VOC变异的主要原因。2-丙醇,十六烷,3-甲基丁醇,乙酸,乙酸丙酯,乙酸甲酯,和3-丁烯腈被鉴定为分解中期的VOC标记,在污染的前48小时,1-辛烯-3-醇被认为是沙门氏菌污染鸡的VOC标记。这为禽肉中沙门氏菌污染VOC标志物的研究提供了理论依据。
    Salmonella is one of the most prevalent foodborne pathogens in poultry and its products. Its rapid detection based on volatile organic compounds (VOC) has been widely accepted. However, the variation in the VOCs of Salmonella-contaminated chicken during the early stage (48 h) remains uncertain. Headspace-SPME-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) were used to identify VOCs and their variations after the chicken meat was contaminated with Salmonella. Chemometric and KEGG enrichment analyses were performed to identify VOC markers and their potential metabolic pathways. A total of 64 volatile compounds were detected using HS-GC-IMS, which showed a better differentiation than HS-SPME-GC-MS (45 volatile compounds) based on principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). Fatty acid degradation was the main cause of VOC variation. 2-Propanol, hexadecane, 3-methylbutanol, acetic acid, propyl acetate, acetic acid methyl ester, and 3-butenenitrile were identified as VOC markers in the middle stage of decomposition, and 1-octen-3-ol was recognized as a VOC marker of Salmonella-contaminated chicken during the first 48 h of contamination. This provides a theoretical basis for the study of Salmonella contamination VOC markers in poultry meat.
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