The physical separation of particulates

Particulates are present in the atmosphere as a result of both natural and man-made processes. Typical particulates include windblown soil, sea salt, sulphur, nitr0gen and hydrocarbon complexes, ammonium sulphate and nitrate, carbonaceous matter, biological debris, metal oxides, trace metals, and extra-terrestrial magnetic and radioactive compounds. Natural processes such as cloud formation, rainfall, and sedimentation cleanse the atmosphere of these particulates and, in so doing, form particle groups or agglomerates which can contain many unit particles. For the purpose of atmospheric research and, in particular, the physical tracing of pollution sources, particulates are a useful emission indicator. Consequently, if one wishes to use them effectively, it is necessary to separate the agglomerate into its independent particle units prior to analysis and identification. This is no simple matter, as the particles are held together by strong physical forces. The purpose of this thesis is to investigate a method of separating particulates for physical tracer studies, but the atmospheric aerosol was considered too complex a model for the initial studies. [Continues.]