The Experts below are selected from a list of 80631 Experts worldwide ranked by ideXlab platform
Hwai-shen Liu - One of the best experts on this subject based on the ideXlab platform.
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absorption of hydrophobic Volatile Organic Compounds by a rotating packed bed
Industrial & Engineering Chemistry Research, 2012Co-Authors: Chiaying Chiang, Yu-shao Chen, Yiying Liu, Hwai-shen LiuAbstract:The high development of industries leads to significant amount of waste hydrophobic Volatile Organic Compounds (VOCs), and these have caused serious environmental concerns. Because of the physical properties of the hydrophobic VOCs, a hydrophobic absorbent is needed in order to make the process more efficient if absorption is considered. However, most of these absorbents have high viscosities which leads to a low mass transfer coefficient. Thus, a cross-flow rotating packed bed (RPB) was evaluated for the feasibility of absorbing the hydrophobic VOCs, xylene, and toluene, by silicon oil, a model hydrophobic absorbent. The result shows that the absorption percentage could be up to 98% within a second contact of liquid and gas.
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Volatile Organic Compounds absorption in a cross flow rotating packed bed
Environmental Science & Technology, 2008Co-Authors: Yu-shao Chen, Chia-chang Lin, Yichun Hsu, Clifford Y Tai, Hwai-shen LiuAbstract:A cross-flow rotating packed bed (RPB) process was evaluated for its absorption of some Volatile Organic Compounds (VOCs) into water, including isopropyl alcohol, acetone, and ethyl acetate. The experimental results showed that the mass transfer coefficient (KGa) increased with increasing rotational speed, liquid rate, and gas rate, and thus an empirical correlation of KGa was proposed for the cross-flow RPB for the first time. It was found that this correlation could reasonably estimate our experimental KGa data as well as those reported in literatures. Although the mass transfer coefficient was lower than that in a countercurrent-flow RPB, a cross-flow RPB is believed to be capable of handling a higher gas rate because of its flow pattern.
Paul K S Lam - One of the best experts on this subject based on the ideXlab platform.
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odor pollution due to industrial emission of Volatile Organic Compounds a case study in hefei china
Journal of Cleaner Production, 2020Co-Authors: Guijian Liu, Hong Zhang, Huaqin Xue, Xin Wang, Paul K S LamAbstract:Abstract Odor pollution as an environmental nuisance has attracted a lot of public attention. A great number of Volatile Organic Compounds are capable of causing odor problems, most of which are accompanied by adverse health effects. Volatile Organic compound samples were collected from different sites in the high-tech industry development zone in Hefei, including various kinds of factories and residential areas. The samples were analyzed by gas chromatography and mass spectrometry detection, and the analysis results showed that the concentrations of total Volatile Organic Compounds ranged from 285.30 to 1802.30 ppbv. Among the 80 specific Volatile Organic Compounds studied, 46 Compounds detected could lead to odor pollution according to the odor threshold. To provide comprehensive characterization of odor pollution, instrumental analysis combined with olfactory measurement were conducted in this study. Odor Volatile Organic Compounds were characterized by using olfactory odor concentration, odor index and coefficient of divergence analysis methods. According to the results, the automobile components manufacturing plants and electric products plants exhibited the highest concentrations of odor Volatile Organic Compounds among all the major emission sites, especially during the injection molding and spraying. Specifically, 1,4-diethylbenzene was the most abundant odorous contributor in this study. Furthermore, the profiles of each Volatile Organic Compounds at the industrial sites were quite different from those at the residential sites, which can be deduced that the surrounding residential zones were not strongly affected by the Volatile Organic Compounds emission from the industrial zones.
Lars Molhave - One of the best experts on this subject based on the ideXlab platform.
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total Volatile Organic Compounds tvoc in indoor air quality investigations
Indoor Air, 1997Co-Authors: Lars Molhave, Geo Clausen, Birgitta Berglund, J De Ceaurriz, A Kettrup, Thomas Lindvall, M Maroni, A C Pickering, U Risse, H RothweilerAbstract:Abstract The amount of Volatile Organic Compounds (VOCs) in indoor air, usually called TVOC (total Volatile Organic Compounds), has been measured using different definitions and techniques which yield different results. This report recommends a definition of TVOC referring to a specified range of VOCs and it proposes a method for the measurement of this TVOC entity. Within the specified range, the measured concentrations of identified VOCs (including 64 target Compounds) are summed up, concentrations of non-identified Compounds in toluene equivalents are added and, together with the identified VOCs, they give the TVOC value. The report reviews the TVOC concept with respect to its usefulness for exposure assessment and control and for the prediction of health or comfort effects. Although the report concludes that at present it is not possible to use TVOC as an effect predictor, it affirms the usefulness of TVOC for characterizing indoor pollution and for improving source control as required from the points of view of health, comfort, energy efficiency and sustainability.
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Volatile Organic Compounds indoor air quality and health
Indoor Air, 1991Co-Authors: Lars MolhaveAbstract:This publication summarizes field investigations and controlled experiments on the relation between low levels of indoor air pollution with Volatile Organic Compounds (VOC) and human health and comfort. The Henle-Kock criteria from epidemiology are revised for the dose-response relation between VOC's and health as comfort effects and existing evidence for each criterion are discussed. A biological model for human responses is suggested, based on three mechanisms: sensory perception of the environment, weak inflammatory reactions, and environmental stress reactions. Further, the TVOC-indicator concept for exposure is discussed. The conclusion is that no experimental or field data contradict the proposed causality. On the contrary, evidence supports the suggested causality. The biological model, however, is not yet based on acceptable measures of the variables for exposures, co-variables or health effects. A tentative guideline for VOC's in non-industrial indoor environments is suggested. The no-effect level seems to be about 0.2 mg/m3. A multi-factorial exposure range may exist between 0.2 and 3 mg/m3. Above 3 mg/m3 discomfort is expected.
Guijian Liu - One of the best experts on this subject based on the ideXlab platform.
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odor pollution due to industrial emission of Volatile Organic Compounds a case study in hefei china
Journal of Cleaner Production, 2020Co-Authors: Guijian Liu, Hong Zhang, Huaqin Xue, Xin Wang, Paul K S LamAbstract:Abstract Odor pollution as an environmental nuisance has attracted a lot of public attention. A great number of Volatile Organic Compounds are capable of causing odor problems, most of which are accompanied by adverse health effects. Volatile Organic compound samples were collected from different sites in the high-tech industry development zone in Hefei, including various kinds of factories and residential areas. The samples were analyzed by gas chromatography and mass spectrometry detection, and the analysis results showed that the concentrations of total Volatile Organic Compounds ranged from 285.30 to 1802.30 ppbv. Among the 80 specific Volatile Organic Compounds studied, 46 Compounds detected could lead to odor pollution according to the odor threshold. To provide comprehensive characterization of odor pollution, instrumental analysis combined with olfactory measurement were conducted in this study. Odor Volatile Organic Compounds were characterized by using olfactory odor concentration, odor index and coefficient of divergence analysis methods. According to the results, the automobile components manufacturing plants and electric products plants exhibited the highest concentrations of odor Volatile Organic Compounds among all the major emission sites, especially during the injection molding and spraying. Specifically, 1,4-diethylbenzene was the most abundant odorous contributor in this study. Furthermore, the profiles of each Volatile Organic Compounds at the industrial sites were quite different from those at the residential sites, which can be deduced that the surrounding residential zones were not strongly affected by the Volatile Organic Compounds emission from the industrial zones.
Chiaying Chiang - One of the best experts on this subject based on the ideXlab platform.
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absorption of hydrophobic Volatile Organic Compounds by a rotating packed bed
Industrial & Engineering Chemistry Research, 2012Co-Authors: Chiaying Chiang, Yu-shao Chen, Yiying Liu, Hwai-shen LiuAbstract:The high development of industries leads to significant amount of waste hydrophobic Volatile Organic Compounds (VOCs), and these have caused serious environmental concerns. Because of the physical properties of the hydrophobic VOCs, a hydrophobic absorbent is needed in order to make the process more efficient if absorption is considered. However, most of these absorbents have high viscosities which leads to a low mass transfer coefficient. Thus, a cross-flow rotating packed bed (RPB) was evaluated for the feasibility of absorbing the hydrophobic VOCs, xylene, and toluene, by silicon oil, a model hydrophobic absorbent. The result shows that the absorption percentage could be up to 98% within a second contact of liquid and gas.
