Heterogeneous and Liquid-Phase Processes

Peter Warneck (Mainz) Editor and Coordinator

Although clouds are known to be effective processors for the production of acidified precipitation and the modification of photo-oxidant concentrations in the atmosphere, the detailed physical and chemical processes by which the changes occur are still far from understood and are the subject of vigorous current research. The book presents recent advances in the field including photochemical and free radical reactions in cloud droplets, reaction mechanisms for the oxidation of sulfur (IV) by ozone and hydrogen peroxide, the role of transition metal ions in aqueous oxidation, the exchange of pollutants between the air and cloud droplets, and some studies of aerosol surface reactions and photocatalysis. The book is volume 2 of the series on Transport and Chemical Transformation of Pollutants in the Troposphere.

Table of Contents

Preface by the HALIPP Steering Group

Chapter 1.

1.1. Highlights of the Results
1.2. Original Aims of the EUROTRAC Subproject HALIPP

Chapter 2. Review of the Activities and Achievements of the EUROTRAC Subproject HALIPP
P. Warneck, P. Mirabel, G.A. Salmon, R. van Eldik, C. Vinckier, K.J. Wannowius and C. Zetzsch

2.1. Introduction
2.2. Sulfur (IV) Oxidation by Ozone, Hydroperoxides and Hypochlorous Acid
2.3. Transition Metal Ions and Their Role in Atmospheric Waters
2.4. Photochemical Sources of Radicals in Atmospheric Water Drops
2.5. Free Radical Reactions in the Aqueous Phase
2.6. Gas–Liquid Interactions
2.7. Aerosol Surface Reactions and Photocatalysis
2.8. General Conclusions

Individual Reports from HALIPP Contributors

Chapter 3. Sulfur(IV) Oxidation

3.1. Kinetic investigation of the stability of peroxonitric acid and its reaction with sulfur(IV) in aqueous solution
T. Amels, H. Elias, U. Götz, U. Steingens and K.J. Wannowius (Darmstadt)

3.2. Electrolyte effects on aqueous oxidation of sulfur dioxide by strong oxidants
J. Lagrange, P. Lagrange, C. Pallarès and G. Wenger (Strasbourg)

Chapter 4. Transition Metal Ions in Atmospheric Waters

4.1. Metal ion catalysed autoxidation of dissolved sulfur dioxide
J. Berglund and L.I. Elding (Lund)

4.2. Catalytic effects of atmospheric aerosol particles in aqueous phase of trace gases
I. Grgic, M. Poje, M. Novic, M. Bizjak and V. Hudnik (Ljubljana)

4.3. Kinetics of ozonation processes in cloud and fog water: Effect of transition metal ions on free radical reactions
J. Hoigné and R. Bühler (Dübendorf/Zürich)

4.4. Kinetics of S(IV) oxidation in aqueous solution: Impact of transition metal ion transformations
W. Pasiuk-Bronikowska, K.J. Rudzinski, T. Bronikowsk and J. Ziajka (Warsaw)

4.5. The interaction of SOx and NOy species in aqueous solution: Photo and metal ion catalysis
R. van Eldik, M. Geißler, C. Brandt and V. Lepentsiotis (Erlangen)

Chapter 5. Photochemical Sources and Reactions of Free Radicals in the Aqueous Phase

5.1. Kinetics and mechanisms of acid generation in clouds and precipitation
G.V. Buxton, G.A. Salmon, S. Barlow, T.N. Malone, S. McGowan,S.A. Murray, J.E. Williams, N.D. Wood (Leeds)

5.2. Chain oxidation mechanisms of S(IV) in aqueous solution: Application of radical scavenger techniques
P. Warneck, H.-J. Benkelberg, U. Deister, M. Fischer, A. Schäfer and J. Ziajka (Mainz)

5.3. Formation and reaction of oxidants in the aqueous phase
R. Zellner, H. Herrmann, M. Exner, H.-W. Jacobi, G. Raabe and A. Reese (Essen)

Chapter 6. Gas - Liquid Interactions

6.1. Photocatalysis of tropospheric chemistry by sea spray
W. Behnke, M. Elend, A. Frenzel, C. George, H.-U. Krüger,V. Scheer and C. Zetzsch (Hannover)

6.2. Phase partitioning and redox processes in fog and cloud systems
W. Jaeschke, J. Dierssen, S. Volkwein and J. Wohlgemuth (Frankfurt/Main)

6.3. Gas - liquid interactions
P. Mirabel, C. George, L. Magi and J.L. Ponche (Strasbourg)

6.4. Laboratory determination of physico-chemical rate parameters pertinent to mass transfer into cloud and fog droplets
U. Schurath, A. Bongartz, J. Kames, C. Wunderlich, T. Carstens (Bonn)

Chapter 7. Aerosol Surface Reactions and Photocatalysis

7.1. Determination of ß pinene OH radical rate constant – possible impact of solid particles
P. Foster, I. Denis and V. Jacob (Grenoble)

7.2. Calorimetric study of Lewis acid centres and adsorbed water in the heterogeneous reactions involving tropospheric particles
J.-C. Petit and J. Thlibi (Orléans)

7.3. Laboratory studies of the phototransformation of organic compounds in the presence of water and/or inorganic particulate solids
P. Pichat, C. Guillard, C. Hoang-Van, H. Delprat, D. Mas, F. Marme, T. Bouvier and B. Servajean (Lyon)

7.4. Heterogeneous reactions of nitrogen oxides (NO2, N2O5, HNO3, ClONO2) with surfaces representative of atmospheric aerosol
M.J. Rossi, F.F. Fenter, K. Tabor, F. Caloz and L. Gutzwiller (Lausanne)

7.5. Heterogeneous reactions of air pollutants on various solid surfaces
C. Vinckier, N. Van Hoof, S. Ashty and F. Compernolle (Leuven)

Chapter 8. HALIPP Publications 1988-1995