Atmospheric photooxidation of organosulphur compounds

Citation

Yin, Fangdong (1990) Atmospheric photooxidation of organosulphur compounds. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/9gn5-p598. https://resolver.caltech.edu/CaltechETD:etd-11192007-092214

Abstract

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The atmospheric chemistry of organosulfur compounds is of fundamental importance to understanding the biogeochemical sulfur cycle as well as environmental issues such as acid precipitation and sulfur aerosol formation in the atmosphere. The research goal of the present work is to elucidate the atmospheric reaction mechanisms of conversion of organosulfur compounds to sulfur-containing aerosols.

Based on the fundamental chemistry and the available kinetic and mechanistic information from experimental studies, detailed chemical reaction mechanisms have been developed for the atmospheric photooxidation of dimethyl sulfide, [...], dimethyl disulfide, [...], methanethiol, [...], and diethyl sulfide, [...]. Predictions of the developed mechanisms by computer simulation are compared with available data on laboratory photooxidation of organosulfur compounds to identify critical uncertainties in chemical pathways and reaction rate constants. Further experimental studies have been designed based on the findings from computer modeling work. Using the outdoor smog chamber reactor, the dynamic behavior of various chemical species and particle nucleation and growth have been investigated in detail under well-defined atmospheric conditions for systems [...] and [...]. Through analysis of the experimental data from outdoor smog chamber experiments by computer simulation, the mechanisms developed for photooxidation of [...] and [...] have been evaluated and reformulated. The key problems regarding the initial reactions, secondary reactions of RSOX radicals and [...] radicals, and the major chemical pathways for the formation of [...] and [...] compounds have been elucidated and the discrepancies of the experimental results between different investigators have been resolved. Critical uncertatinties regarding chemical path- ways and reaction rate constants have been identified and further detailed kinetic experimental studies have been recommended.

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