TY - CHAP

T1 - Influence of clouds on the photochemical degradation in aqueous phase - II

T2 - Wasser 2008 - Jahrestagung

AU - Palm, Wolf-Ulrich

AU - Meyer-Grünefeld, Maren

AU - da Rosa, M.B.

AU - Ruck, Wolfgang

PY - 2008

Y1 - 2008

N2 - The photolysis of pesticides in aqueous solution is one of the key parameters usedassess their persistence in the environment. However:III Photolysis lifetimes at different latitudes are obtained from quantum yields and UVspectra in the laboratory together with calculated sunlight intensities. Comparison ofexperimentally determined photolysis rates at different latitudes and under differentclimatic conditions for pesticides has seldom been performed.III Photolysis lifetimes of pesticides at different latitudes are usually calculated at noonfor summer months and have to be regarded as progressive values. Hence, theinfluence of cloud cover on the photolysis is often neglected or not known.We discuss on the poster:III the comparison of the photolysis at two differing sites in the northern part ofGermany (LOneburg) and the southern part of Brazil (Santa Maria) with respect toclimate and sunlight intensity,• diurnal variations of the photolysis reaction were in the focus of the measurementperformed with the herbicide metamitron (properties of metamitron are discussedon an accompanying poster),• an attempt to explain the photolysis-rate constants using a well established model(STARsci) especially considering the influence of clouds,• an assessment of the deviation of the "clear-sky" scenario often used for pesticidesand the influence of effective sun-light intensities influenced by clouds.

AB - The photolysis of pesticides in aqueous solution is one of the key parameters usedassess their persistence in the environment. However:III Photolysis lifetimes at different latitudes are obtained from quantum yields and UVspectra in the laboratory together with calculated sunlight intensities. Comparison ofexperimentally determined photolysis rates at different latitudes and under differentclimatic conditions for pesticides has seldom been performed.III Photolysis lifetimes of pesticides at different latitudes are usually calculated at noonfor summer months and have to be regarded as progressive values. Hence, theinfluence of cloud cover on the photolysis is often neglected or not known.We discuss on the poster:III the comparison of the photolysis at two differing sites in the northern part ofGermany (LOneburg) and the southern part of Brazil (Santa Maria) with respect toclimate and sunlight intensity,• diurnal variations of the photolysis reaction were in the focus of the measurementperformed with the herbicide metamitron (properties of metamitron are discussedon an accompanying poster),• an attempt to explain the photolysis-rate constants using a well established model(STARsci) especially considering the influence of clouds,• an assessment of the deviation of the "clear-sky" scenario often used for pesticidesand the influence of effective sun-light intensities influenced by clouds.

KW - Chemistry

M3 - Article in conference proceedings

SN - 978-3-936028-51-5

SP - 195

EP - 199

BT - Wasser 2008 - Jahrestagung der Wasserchemischen Gesellschaft

PB - GDCh, Wasserchemische Gesellschaft

CY - Berlin

Y2 - 28 April 2008 through 30 April 2008

ER -