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VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Reconstruction of airborne emissions by inverse dispersion modelling and.

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Presentation on theme: "VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Reconstruction of airborne emissions by inverse dispersion modelling and."— Presentation transcript:

1 VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik
Reconstruction of airborne emissions by inverse dispersion modelling and generation of synthetic emission data by a Monte Carlo model G. Schauberger1, M. Piringer2, E. Petz2, W. Knauder2 and K. Baumann-Stanzer2 1 Medical Physics and Biostatistics Department of Biomedical Sciences Veterinärmedizinischen Universität Wien 2 Central Institute for Meteorology and Geodynamics Department of Environmental Meteorology

2 VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik
Content Two-step procedure to re-construct the emissions of a thermal treatment plant for waste: Step 1: Re-calculate emissions from measured ambient concentrations leeward of the pollution source (“inverse dispersion modelling”) Step 2: Application of a Monte-Carlo model to supplement the emission flow rates by step 1 by synthetic ones to generate emission time series over the entire year Model performance Summary of results and application of the method

3 Site 265 235 Source Ambient concentration
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Site Ambient concentration 265 235 Source

4 Step 1: Inverse dispersion modelling
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Step 1: Inverse dispersion modelling Wind Stability Camb Emission flow rate Q Q

5 Analysis of ambient concentrations (I)
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Analysis of ambient concentrations (I) 265° 235° 235 Mean concentration (in µg/m³) as a function of wind direction for a wind velocity v >0.8m/s

6 Analysis of ambient concentrations (II)
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Analysis of ambient concentrations (II) Ambient concentration time series Intermittence factor IF Fraction of values above a certain threshold (=0 or detection limit) Working days and weekends are taken into account Emission flow rate Time

7 Results for the intermittence factor
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Results for the intermittence factor 265° 235°

8 Step 2: Monte Carlo model
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Step 2: Monte Carlo model To set up the model, a data analysis (data set of step 1) is carried out to determine predictors which describe the data set appropriately: First group: Influence of meteorology (Wind velocity, air temperature) Second group: Process flow of the plant (day of the week, time of the day) Regression analysis of the two meteorological parameters shows a high regression coefficient for the logarithmically transformed values of the emissions of the seven species The appropriate theoretical distribution function to describe the emissions is the log-normal distribution

9 Influence of meteorological parameters
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Influence of meteorological parameters Air temperature Wind velocity

10 Influence of the process flow
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Influence of the process flow Day of the week Daytime 80% 20% Example: Ethyl acetate

11 Statistics of the emissions
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Statistics of the emissions CDF: log-normal distribution Butyl acetate Benzene

12 VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik
Monte-Carlo Model Input parameters Air temperature Wind velocity Day of the week Time of the day Model parameters Intermittence factor IF (diurnal variation for working day and weekend) 3 x 3 matrix for air temperature and wind velocity with mean value and variance Relative diurnal variation of mean value and variance for all days Monte-Carlo Model Evenly distributed random number RN1 log-normally distributed random number RN2 Output parameter Emission mass flow E

13 Comparison synthetic – empirical emission data
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Comparison synthetic – empirical emission data Comparison of the synthetic emission data Emod (Monte-Carlo model) with empirical emission data Emeas (inverse dispersion model) for ethyl acetate, in form of a qq-plot

14 Comparison synthetic – empirical emission data
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Comparison synthetic – empirical emission data Comparison Emod (light grey) and Emeas (dark grey) for butyl acetate (mean values and standard deviations)

15 VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik
Summary Two-step procedure to re-construct emission data of the thermal treatment plant for waste: Step 1: Inverse dispersion modelling Step 2: Monte Carlo model Predictors for the Monte Carlo model: Environmental predictors: Air temperature and wind velocity Process flow predictors: day of the week and time of the day Synthetic emission data were generated A good agreement between measured and modelled emission data can be achieved. Both the range of emissions as well as their time course are well reproduced.

16 Applications Completion of fragmentary emission data
VO Biophysik | G. Schauberger | Institut für Med. Physik & Biostatistik Applications Completion of fragmentary emission data Assessment of emission data derived from short-time measurements Extension of measurements to long time series for the future (e.g. climatic change impacts) 16


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