Heterogeneous and Liquid Phase Processes: Laboratory Studies Related to Aerosols and Clouds (Transport and Chemical Transformation of Pollutants in the Troposphere, V. 2)

Although clouds are known to be effective processors for the production of acidified precipitation and the modification of photooxidant concentrations in the atmosphere, the detailed physical and chemical processes by which the changes occur are still far from understood and are a subject of vigorous current research. This 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 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. The calculation of cross sections and rate constants for chemical reactions in the gas phase has long been a major problem in theoretical chemistry. The need for reliable and applicable theories in this field is evident when one considers the significant recent advances that have been made in developing experimental techniques, such as lasers and molecular beams, to probe the microscopic details of chemical reactions. For example, it is now becoming possible to measure cross sections for chemical reactions state selected in the vibrational­ rotational states of both reactants and products. Furthermore, in areas such as atmospheric, combustion and interstellar chemistry, there is an urgent need for reliable reaction rate constant data over a range of temperatures, and this information is often difficult to obtain in experiments. The classical trajectory method can be applied routinely to simple reactions, but this approach neglects important quantum mechanical effects such as tunnelling and resonances. For all these reasons, the quantum theory of reactive scattering is an area that has received considerable attention recently. This book describes the proceedings of a NATO Advanced Research Workshop held at CECAM, Orsay, France in June, 1985. The Workshop concentrated on a critical examination and discussion of the recent developments in the theory of chemical reaction dynamics, with particular emphasis on quantum theories. Several papers focus on exact theories for reactions.

the European Experiment On The Transport And Transformation Of Environmentally Relevant Trace Constituents Over Europe (eurotrac) Was Established In 1986 To Tackle The Scientific Problem And Combine The Expertise, Knowledge And Resources In Europe, In Order To Apply Them Over A Large Region Covering The Greater Part Of The Continent. Eurotrac Is A Coordinated Multidisciplinary Scientific Research Project Involving Field Measurements, Laboratory Studies, Instrument Development And Development Of Comprehensive Computer Models For The Simulation Of The Physical And Chemical Processes In The Lower Atmosphere.

Front Matter....Pages I-XIX Chapter 1....Pages 1-5 Review of the Activities and Achievements of the EUROTRAC Subproject HALIPP....Pages 7-74 Front Matter....Pages 75-75 Sulfur(IV) Oxidation....Pages 77-96 Transition Metal Ions in Atmospheric Waters....Pages 97-131 Photochemical Sources and Reactions of Free Radicals in the Aqueous Phase....Pages 133-152 Gas—Liquid Interactions....Pages 153-189 Aerosol Surface Reactions and Photocatalysis....Pages 191-226 HALIPP Publications: 1988–1995....Pages 227-250 Back Matter....Pages 251-254 Proceedings of the NATO Advanced Research Workshop, Orsay, France, June 17-30, 1985