Measured and Predicted Leaching of Film Preservatives in Coatings

Transcription

1 Measured and Predicted Leaching of Film Preservatives in Coatings Michael Burkhardt HSR University of Applied Sciences Rapperswil, Institute of Environmental and Process Engineering (UMTEC), 864 Rapperswil, Switzerland Cologne, 22 th October 215

2 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 2

3 Algae and Fungi Growth on Façades and Roofs Widespread biodeterioration on material surfaces 3

4 Growth Control by Biocides in Film Preservatives (PT7) 1,2 Combination of 2 to 4 biocides in use to control algae and fungi growth Concentration of each biocide 2 to 2 ppm Substance Class Biocide Solubility 2 (mg/l) logpow 2 Persistence Amounts Triazine Irgarol high no use Terbutryn high high Phenylurea Diuron high high Isoproturon high low Isothiazolinone DCOIT medium low OIT low high Carbamate IPBC low low Carbendazim medium medium Metal organic Zinc pyrithione 8.9 medium high 1 Burkhardt & Dietschweiler (213): Mengenabschätzung von Bioziden in Schutzmitteln in der Schweiz. Bericht, BAFU, Bern. 2 Paulus, w. 24, Springer. 4

5 Film Preservatives used in Exterior Coatings (PT7) 1,2 Biocide amounts: Germany 25 to 4 t/a, Switzerland 1 to 3 t/a Render, paints: Germany 248' t/a, Switzerland 22' t/a Tons per Year (t/a) Germany maximum minimum Tons per Year (t/a) Switzerland Maximum Minimum 1 Burkhardt, M, et al. (213): Mengenabschätzung von Filmschutzmitteln in Bautenfarben und putzen, Holzschutzmitteln, Mauerschutzmitteln und Antifoulingmitteln in der Schweiz. BAFU, Bern. 2 Burkhardt, M, et al. (215): Reduction of environmental risks from the use of biocides: Environmental sound use of disinfectants, masonry preservatives and rodenticides Annex IV: Case study on PT 7/1: Masonry preservatives and facade paints and plaster. UBA, Dessau-Roßlau. 5

6 Pathways of Biocides from Coatings to Aquatic Systems Different sources (substances, products) and pathways to variety of environmental compartments (e.g. soils, receiving waters) Building Surface Runoff Drainage Emission Sewer Systems Infiltration Separated Sewer Combined Sewer Pathways Immission to soil, surface water and groundwater Soil Diffuse Storm Water Combined Sewer Overflow Waste Water Waste Water & Storm Water Waste Water Treatment Plant Point 6

7 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 7

8 Runoff at Façade of Model House (Zurich) Relevant factors for runoff: weather, orientation, heights Runoff amount corresponding to <1% of annual precipitation (815 mm), in 1% of the rainfall events runoff did not occur Relative Proportion Frequency (%) (%) Zurich Model House (render): 1.8 m façade heights, 62 runoff events in 372 days Runoff Runoff Fraction vs. Precipitation (% of Precipitation (%) ) 8

9 Runoff at Different Façades The smaller the façade, the larger the runoff per square meter (m 2 ) Runoff overestimated at small test specimen at least by factor 1 height <1.5 m = runoff >1% height m = runoff 1-1% height >5 m = runoff <1% 1 IBP,.4 m Facade Runoff (%) 1 1 RMI, 1. m Zurich, Eawag, mm Thor, 3.8 m Zurich, Eawag, 1.5 m Height (m) 9

10 Leaching at Façade of Model House (Zurich) Significant influence of temperature and moisture on concentration, but tendency of concentration decrease Concentration pattern always different to laboratory 6 5 Initially in render C = 2365 mg/m 2, 34 events analysed in 372 days Terbutryn Terbutryn (µg/l) Number of Events (-) 1

11 Occurrence in Swiss Surface Water 1 Diffuse occurrence with temporal variation due to varying emission and dry-/wet weather flow regime Concentration Terbutryn (μg/l) «Furtbach» (area of Zurich) Flow (m 3 /s) WFD set EQS of.65 µg/l in surface water 1 Sinniger et al. (212): Pestiziduntersuchung, AWEL, Zürich. Concept for release and immission dynamics needed 11

12 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 12

13 Concept: Modelling Leaching and Environmental Exposure Simple models are used for registering biocides under BPR Potential of numerical models demonstrated by science Kumulierter Abfluss (m 3 ) 4' 3' 2' 1' Konzentration (mg/l) Kriterium akut Abfluss Dauer Anzahl Jahr '2 1' Niederschlag (mm/h) Akute Überschreitung (Anzahl, h) Gramm Terbutryn pro Jahr und Hektare 2 Dreigeschossige MFH (2-27) 18 Zweigeschossige E/ZFH (26) 16 Zweigeschossige Häuser ( ) Szenarienjahr 13

14 Benefit of Using Numerical Models Simulation is able to reflect the dynamics of emissions and fluctuating immission for defined scenarios or specific requirements Sensitive analysis and variation of parameters give advice to identify substances and areas of concern Boundary conditions based on default values or set by users Emission and receiving compartments Example of scenario: BPR house 2.5 m Surface water 14

15 COMLEAM: Construction Materials Leaching Model COMLEAM is a user friendly software for the simulation of leaching and environmental risk (drop-down menu; programmed in Java) Interfaces (IC) are virtual compartments for risk assessments (e.g. point-of-compliance, POC) or data export to e.g. PELMO, Orchestra Emission and receiving compartments Implementation in COMLEAM IC IC Surface water PELMO Interface-compartment (IC) switch flow and acts as collector, distributor and POC IC 15

16 COMLEAM Approach and Structure Geometry, e.g. heights, lengths, orientation, component to city (GIS) Weather, e.g. precipitation, wind direction and speed (FOCUS-data) Runoff simulation is based on driving rain (ISO :29) Emission, based on number of factors Leaching: data from field or laboratory (e.g. test EN1615) Material and substance properties: database and individual data Emission functions: Time1-Time2 (BPR), detailed, log-function, 2-phases Component, Single House Settlement City IC IC IC 16

17 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 17

18 COMLEAM: Prediction of Driving Rain Simulated driving rain events in line with measured runoff (left) West façade is relevant for runoff at Zurich model house (right) Wind direction and wall factor (heights) are sensitive parameters Measured Runoff (L/m 2 ) ( ) Zurich Model House Slope R-Square W NW Predicted Cumulated Driving Rain (L/m 2 ) N NE E NW NE Predicted Driving Rain (L/m 2 ) S 18

19 COMLEAM: Testing of Emission Functions Input: Emission functions developed at Zurich model house leaching Function Time1-Time2 limited to linear emission is far from reality Function Detailed based on field data to mimic peak emissions: Events largely varying and significant differences for each façade Emission (mg/m 2 ) Time1 Time2: smooth by linearity west south east Detailed: dynamic by peak emission west south east north Time (days) north Time (days) 19

20 COMLEAM: Modelling Emissions of Various Biocides Accurate prediction of leaching with function Detailed for west façade Emission (mg/m 2 ) Diuron Zurich Model House COMLEAM IPBC Zurich Model House COMLEAM Emission (mg/m 2 ) OIT Zurich Model House COMLEAM DCOIT COMLEAM Zurich Model House Time (days) Time (days)

21 COMLEAM: Sensitivity of Predicted Emissions Deviation between predicted and measured cumulated emission rather small using function Detailed for model house leaching (Calibration and validation of model still in progress) Deviation from Measured Emission (%) 21

22 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 22

23 Measured Emissions at Two Sites Conditions of two field studies with renders containing Terbutryn Zürich (Model house): west, start January, 1.8 m height Ober-Ramstadt (RMI panels): south, start October, 1. m height Slightly different dynamics and relative losses Cumulative Emission (mg/m 2 ) RMI panels Zurich Model House C = 2365 mg/m 2 1.2% C = 127 mg/m 2 1.6% Cumulative Facade Runoff (L/m 2 ) 23

24 Modelled Exposure of Runoff and Emission at Two Sites Differences based on weather conditions (driving rain, temperature) Driving rain amounts in Ober-Ramstadt higher (altitude, wind speed) Similar emissions due to higher concentrations at Zurich model house Predicted Driving Rain (L/m 2 ) Predicted Emission (mg 2 /m 2 ) W NW N NE E W NW N NE E NW NE NW NE S S 24

25 Emissions calculated for three Scenarios Scenarios based on measured emissions of Zurich (west) and Ober- Ramstadt (southwest) and weather data from Hamburg (FOCUS) Event based analysis can be used for a frequency distribution of peaks in runoff of European areas (estimation of upper / lower release) Terbutryn Emission [mg/m 2 ] Zurich Model House % RMI panels % Time (d) Time (d) 25

26 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 26

27 Scenario «New Facade and Separate Sewer» Simulation of leaching to receiving water in an urban catchment (Case study) 7 new buildings, each 4-9 m 2 and facade length 9-14 m Polymeric render with biocides Distance to brook 1 m Leaching function Detailed from model house Stormwater runoff in separate sewer system (direct discharge) 6 days simulation period Weather data from Meteoswiss 27

28 Scenario «New Facade and Separate Sewer» Exposure related emission of a single building Emission at façades deliver biocidal load to surface runoff Interface compartment is passing diluted stormwater to surface water 25 Southwest Cumulated Emission (mg/m 2 ) Northwest Northeast Northeast West East Time (d) 28

29 Impact of Buildings to Surface Water Emission is increasing in surface water by discharged stormwater runoff with respect to the number of buildings (A to G) Peak pollution under wet weather flow (diffuse discharge of biocides) Low concentrations for dry weather flow or by high dilution Concentration (ng/l) A B C D E F G Outcome: Comparison with acute and chronic ecotoxicity values, PEC/PNEC-calucations) Water quality criteria of biocides in surface waters:.1 µg/l Time (d) 29

30 Frequency Distribution of Calculated Concentrations Counted number of events with certain concentrations (classified) Indications of environmental risks with temporal distribution pattern (level of acceptance need to be defined (PEC/PNEC, limit values)) 3.5 Logarithmic Number Events (-) Wich level of risk is acceptable? >2 Concentration (ng/l) 3

31 Structure Motivation Environment COMLEAM Model Validation Testing Scenario Conclusions 31

32 Conclusions Field studies are time consuming and influenced by number of variables ( representative and reproducible) Models delivers new insight to sensitivity of parameters and statistical analysis of peak emissions and risks in receiving compartments Modelling are very beneficial for a tiered biocides assessment Tiered 1: Modelling using existing lab / field data and exposure scenarios to screen and classify the environmental risk Tiered 2: Specific field study for substances or scenarios of concern to gain further details and a robust model set-up COMLEAM experiences with flexible modular concept including GIS coupling are promising (available 216, first for ESTIMATE group) 32

33 Acknowledgements HSR-Colleagues Olaf Tietje, Florian Hochstrasser, Dirk Engelke, Farhad Mehta, Silvan Gehrig, Patricia Meier, Patricia Nigg Robert-Murjahn-Institute (RMI), Ober-Ramstadt/D Nicole Borho, Helge Kramberger-Kaplan ESTIMATE-Colleagues for fruitful discussions RWTH Aachen/D RMI, Ober-Ramstadt/D IME, Schmallenberg/D BAM, Berlin/D ECN, Patten/NL Funding Swiss federal Office for the Environment (FOEN), Berne/CH HSR University of Applied Sciences, Rapperswil/CH 33

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