3 Control of PM1

  Control of Particulate Matter Dr. Wesam Al Madhoun  What is Particulate Matter? ã  Particulate matter (PM)  describes a wide variety of airborne material. PM pollution consists of materials (including dust, smoke, and soot), thatare directly emitted into the air or result from the transformation of gaseous pollutants. ã  Particles come from natural sources (e.g., volcanic eruptions) and human activities such as burning fossil fuels, incinerating wastes, and smeltingmetals.   haracteristics of Particles ã  The most important characteristic of particulate matter (PM) isthe  particle size . ã  This property has the greatest impact on the behavior of particulate matter in control equipment, the atmosphere, andthe respiratory tract. ã  Particles of importance in air pollution control span a broadsize range from extremely small (0.01 micrometer) to morethan 1,000 micrometers. ã  As a frame of reference, a human hair has a diameter of approximately 50 micrometers.  ã  The chemical composition of the particulate matter is alsoimportant. ã  Absorption and heterogeneous nucleation of vapor phasepollutants onto existing particles can create toxic particulatematter. ã  Other characteristics besides size and chemical compositionshould be considered when selecting an appropriateparticulate control device for a gas stream. ã  Other important characteristics of particulate matter in gasstreams include stickiness and explosiveness.