The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Heribert Fleer - One of the best experts on this subject based on the ideXlab platform.
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simulating surface Plant Air interactions inside urban environments with a three dimensional numerical model
Environmental Modelling and Software, 1998Co-Authors: Michael Bruse, Heribert FleerAbstract:Abstract In recent years high-resolution numerical simulation of surface–Plant–Air interactions as an important part of global circulation models (GCM) or as a tool to assist in planning decisions has experienced increased consideration. In contrast large scale phenomena described in GCMs, the lower part of the atmosphere where we live is very sensitive to small scale processes which can develop an individual local climate, different to the expected average conditions. Especially in urban areas the great variety of different surfaces and sheltering obstacles produces a pattern of distinct microclimate systems. To simulate these local effects, microscale surface–Plant–Air interaction schemes with a special extension to typical artificial urban boundaries are needed. The paper focuses on the microscale numerical simulation of surface–Plant–Air interactions inside urban structures, especially the feedback between artificial surfaces like buildings and vegetation inside street canyons, backyards or greens. The three-dimensional non-hydrostatic model ENVI-met is presented and used to solve the basic equations forward in time and can simulate `hard' wind field modifications (solid boundaries) like walls as well as `soft' modifications (porous shelters) like vegetation. A case study of building a small park inside the CBD area will show what effects even small changes can have on local flow and temperature fields.
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Simulating surface–Plant–Air interactions inside urban environments with a three dimensional numerical model
Environmental Modelling and Software, 1998Co-Authors: Michael Bruse, Heribert FleerAbstract:Abstract In recent years high-resolution numerical simulation of surface–Plant–Air interactions as an important part of global circulation models (GCM) or as a tool to assist in planning decisions has experienced increased consideration. In contrast large scale phenomena described in GCMs, the lower part of the atmosphere where we live is very sensitive to small scale processes which can develop an individual local climate, different to the expected average conditions. Especially in urban areas the great variety of different surfaces and sheltering obstacles produces a pattern of distinct microclimate systems. To simulate these local effects, microscale surface–Plant–Air interaction schemes with a special extension to typical artificial urban boundaries are needed. The paper focuses on the microscale numerical simulation of surface–Plant–Air interactions inside urban structures, especially the feedback between artificial surfaces like buildings and vegetation inside street canyons, backyards or greens. The three-dimensional non-hydrostatic model ENVI-met is presented and used to solve the basic equations forward in time and can simulate `hard' wind field modifications (solid boundaries) like walls as well as `soft' modifications (porous shelters) like vegetation. A case study of building a small park inside the CBD area will show what effects even small changes can have on local flow and temperature fields.
Michael Bruse - One of the best experts on this subject based on the ideXlab platform.
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simulating surface Plant Air interactions inside urban environments with a three dimensional numerical model
Environmental Modelling and Software, 1998Co-Authors: Michael Bruse, Heribert FleerAbstract:Abstract In recent years high-resolution numerical simulation of surface–Plant–Air interactions as an important part of global circulation models (GCM) or as a tool to assist in planning decisions has experienced increased consideration. In contrast large scale phenomena described in GCMs, the lower part of the atmosphere where we live is very sensitive to small scale processes which can develop an individual local climate, different to the expected average conditions. Especially in urban areas the great variety of different surfaces and sheltering obstacles produces a pattern of distinct microclimate systems. To simulate these local effects, microscale surface–Plant–Air interaction schemes with a special extension to typical artificial urban boundaries are needed. The paper focuses on the microscale numerical simulation of surface–Plant–Air interactions inside urban structures, especially the feedback between artificial surfaces like buildings and vegetation inside street canyons, backyards or greens. The three-dimensional non-hydrostatic model ENVI-met is presented and used to solve the basic equations forward in time and can simulate `hard' wind field modifications (solid boundaries) like walls as well as `soft' modifications (porous shelters) like vegetation. A case study of building a small park inside the CBD area will show what effects even small changes can have on local flow and temperature fields.
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Simulating surface–Plant–Air interactions inside urban environments with a three dimensional numerical model
Environmental Modelling and Software, 1998Co-Authors: Michael Bruse, Heribert FleerAbstract:Abstract In recent years high-resolution numerical simulation of surface–Plant–Air interactions as an important part of global circulation models (GCM) or as a tool to assist in planning decisions has experienced increased consideration. In contrast large scale phenomena described in GCMs, the lower part of the atmosphere where we live is very sensitive to small scale processes which can develop an individual local climate, different to the expected average conditions. Especially in urban areas the great variety of different surfaces and sheltering obstacles produces a pattern of distinct microclimate systems. To simulate these local effects, microscale surface–Plant–Air interaction schemes with a special extension to typical artificial urban boundaries are needed. The paper focuses on the microscale numerical simulation of surface–Plant–Air interactions inside urban structures, especially the feedback between artificial surfaces like buildings and vegetation inside street canyons, backyards or greens. The three-dimensional non-hydrostatic model ENVI-met is presented and used to solve the basic equations forward in time and can simulate `hard' wind field modifications (solid boundaries) like walls as well as `soft' modifications (porous shelters) like vegetation. A case study of building a small park inside the CBD area will show what effects even small changes can have on local flow and temperature fields.
Pim De Voogt - One of the best experts on this subject based on the ideXlab platform.
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sampling and simultaneous determination of volatile per and polyfluoroalkyl substances in wastewater treatment Plant Air and water
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Ian Ken D Dimzon, Joke W Westerveld, Christoph Gremmel, Tobias Fromel, Thomas P Knepper, Pim De VoogtAbstract:Volatile per- and polyfluoroalkyl substances (PFASs) are often used as precursors in the synthesis of nonvolatile PFASs. The volatile PFASs, which include the perfluoroalkyl iodides (PFAIs), fluorotelomer iodides (FTIs), fluorotelomer alcohols (FTOHs), fluorotelomer olefins (FTOs), fluorotelomer acrylates (FTACs), and fluorotelomer methacrylates (FTMACs), are often produced starting from the telomerization process. These volatile compounds can be present in the Air and water environment and can be transformed into highly persistent perfluoroalkyl carboxylic acids. With the exception of FTOHs, which are well studied, the determination of other volatile PFASs is also of prime importance in studying the sources and fate of PFASs. In this study, a method was developed to determine representative precursor compounds that included PFAIs, FTIs, FTOs, FTACs, and FTMACs in wastewater treatment Plant (WWTP) Air and water samples. The sampling and sample preparation step involved the use of solid-phase extraction (SPE) cartridges with HLB™ material to enrich the analyte. Gas chromatography with mass spectrometry was employed for the detection and quantification of the analytes. Method validation results showed high linearity and sensitivity in the positive electron ionization-selected ion monitoring mode (+EI-SIM). The absolute instrumental limits of detection were in the range of 0.5 to 2 pg. The method detection limit (MDL) in Air was 1 ng/m3 with the exception of the FTACs which could be only be detected at concentrations higher than 40 ng/m3. The MDL in water was 10 ng/L. Direct spiking of the cartridges and analyte introduction by volatilization from the glass surface onto the SPE material had recoveries between 86 and 100%. The volatile PFASs were shown to readily partition into the Air rather than into water. Consequently, large losses in the amount of PFASs were observed when these were spiked into the water.
Ian Ken D Dimzon - One of the best experts on this subject based on the ideXlab platform.
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sampling and simultaneous determination of volatile per and polyfluoroalkyl substances in wastewater treatment Plant Air and water
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Ian Ken D Dimzon, Joke W Westerveld, Christoph Gremmel, Tobias Fromel, Thomas P Knepper, Pim De VoogtAbstract:Volatile per- and polyfluoroalkyl substances (PFASs) are often used as precursors in the synthesis of nonvolatile PFASs. The volatile PFASs, which include the perfluoroalkyl iodides (PFAIs), fluorotelomer iodides (FTIs), fluorotelomer alcohols (FTOHs), fluorotelomer olefins (FTOs), fluorotelomer acrylates (FTACs), and fluorotelomer methacrylates (FTMACs), are often produced starting from the telomerization process. These volatile compounds can be present in the Air and water environment and can be transformed into highly persistent perfluoroalkyl carboxylic acids. With the exception of FTOHs, which are well studied, the determination of other volatile PFASs is also of prime importance in studying the sources and fate of PFASs. In this study, a method was developed to determine representative precursor compounds that included PFAIs, FTIs, FTOs, FTACs, and FTMACs in wastewater treatment Plant (WWTP) Air and water samples. The sampling and sample preparation step involved the use of solid-phase extraction (SPE) cartridges with HLB™ material to enrich the analyte. Gas chromatography with mass spectrometry was employed for the detection and quantification of the analytes. Method validation results showed high linearity and sensitivity in the positive electron ionization-selected ion monitoring mode (+EI-SIM). The absolute instrumental limits of detection were in the range of 0.5 to 2 pg. The method detection limit (MDL) in Air was 1 ng/m3 with the exception of the FTACs which could be only be detected at concentrations higher than 40 ng/m3. The MDL in water was 10 ng/L. Direct spiking of the cartridges and analyte introduction by volatilization from the glass surface onto the SPE material had recoveries between 86 and 100%. The volatile PFASs were shown to readily partition into the Air rather than into water. Consequently, large losses in the amount of PFASs were observed when these were spiked into the water.
Francesc Borrull - One of the best experts on this subject based on the ideXlab platform.
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determination of volatile organic compounds in industrial wastewater Plant Air emissions by multi sorbent adsorption and thermal desorption gas chromatography mass spectrometry
Analytical Abstracts, 2012Co-Authors: Noelia Ramirez, R M Marce, Francesc BorrullAbstract:This paper describes the process of determining the presence of volatile organic compounds in Air emissions from industrial wastewater treatment Plants (WWTP). The analytical method, based on thermal desorption-gas chromatography-mass spectrometry, was developed to simultaneously determine of 99 volatile organic compounds (VOCs) in Air samples. This method is rapid, environmentally-friendly (since no organic solvents are used to extract the analytes) and compatible with a large range of thermally stable polar and apolar compounds. The target VOCs were selected on the basis of their occurrence in real samples and their adverse effects on the environment and human health. To cover the wide range of target compounds, multisorbent tubes filled with Tenax TA and Carbograph 1TD were used. Method validation showed good repeatabilities, low detection limits, a high linear range and good recoveries. At a fixed sample volume of 600 mL no significant losses for any of the target compounds were found in the samples. Stability during storage indicated that samples must be keep refrigerated at 4°C and analysed within three days of collection. Real samples were taken from Air emissions of an industrial wastewater treatment Plant located in the Southern Industrial Area of Tarragona (Spain) with the aim of studying its contribution as a source of atmospheric VOCs. This WWTP collects wastewater from several chemical factories which produce isocyanates, polyurethanes, chlorinated organics and functional chemicals among other products. Samples from the collecting tank after the primary sedimentation showed higher VOC concentrations than samples from the secondary treatment tank. The most abundant VOCs found in these emissions are included in the USEPA List of Hazardous Air Pollutants. The highest values correspond to acrylonitrile (up to 1843 µg m-3) and styrene (up to 573.70 µg m-3). The levels of chloroform, 1,4-dioxane, ethylbenzene, 1,2,3-trimethylbenzene and 1,4-diethylbenzene were also high.
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determination of volatile organic compounds in industrial wastewater Plant Air emissions by multi sorbent adsorption and thermal desorption gas chromatography mass spectrometry
International Journal of Environmental Analytical Chemistry, 2011Co-Authors: Noelia Ramirez, R M Marce, Francesc BorrullAbstract:This paper describes the process of determining the presence of volatile organic compounds in Air emissions from industrial wastewater treatment Plants (WWTP). The analytical method, based on thermal desorption-gas chromatography-mass spectrometry, was developed to simultaneously determine of 99 volatile organic compounds (VOCs) in Air samples. This method is rapid, environmentally-friendly (since no organic solvents are used to extract the analytes) and compatible with a large range of thermally stable polar and apolar compounds. The target VOCs were selected on the basis of their occurrence in real samples and their adverse effects on the environment and human health. To cover the wide range of target compounds, multisorbent tubes filled with Tenax TA and Carbograph 1TD were used. Method validation showed good repeatabilities, low detection limits, a high linear range and good recoveries. At a fixed sample volume of 600 mL no significant losses for any of the target compounds were found in the samples. ...