PM - Draft-1 - Fgravity FStartAand Water Cleaning Gas and...

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F gravity F drag F buoyancy Particle Velocity Start Cleaning Begin Filtering A B C D Clean gas out Water and Solids out Gas and Solids in PARTICULATE MATTER 1
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General Information Particles, particulates, and particulate matter (PM) all refer to the mixture of solid particles and liquid droplets found in a gas. The term aerosol refers to the mixture of particulates and gas. Types of particulate matter include acids, organic chemicals, combustion byproducts (soot), metals, soil, and dust. The important gases for pollution aerosols include the exhaust from activities and processes, and atmospheric air. For the purposes of air pollution, the sizes larger than 100 μm are not important as they quickly settle from the atmosphere by gravity and have only a very short time and localized spatial impact. The US EPA has developed terminology for the particle sizes important for air quality, as described in Table . Table - Particle Size Terminology. Alignment is weird Size range in microns [μm] Description > 10 Supercoarse 2.5 to 10 Coarse 0.1 to 2.5 Fine < 0.1 Ultrafine Additional terminology includes total suspended particulate matter (TSP), PM 10 , PM 2.5 , and PM 0.1 (nano-materials). TSP includes all particles in the air. It includes all the particles from all the sizes described in table 1. It is easily measured by weighing a filter before and after it filters a known volume of air. The additional weight on the used filter is the TSP. PM 10 is defined as all the particulate matter with a diameter of less than 10 μm collected by a PM 10 sampling collection device. However, it is easier to consider PM 10 as all the particles having an aerodynamic diameter (needs to be defined?) of 10 μm or less. PM 2.5 is defined as all the particulate matter with a diameter of less than 2.5 μm collected by a PM 2.5 sampling collection device. However, it is easier to consider PM 2.5 as all the particles having an aerodynamic diameter of 2.5 μm or less. The fine particulates settle slowly from air and may take hours to days to be removed from the atmosphere. PM 2.5 typically have a very different chemical composition than the coarse and supercoarse fractions. These smaller sizes are composed primarily of sulfates, nitrates, organic compounds, and metals. Air emission testing and air pollution control methods for PM 2.5 particles are different from those for coarse and supercoarse particles. Particles in the range of 0.2 2
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to 0.5 micrometers are common in many types of combustion, waste incineration, and metallurgical sources PM 0.1 is not a defined size, but the term describes particles with a diameter of less than 0.1 μm or 100 nm. A gas molecule may have a size of 0.2 to 1 nm. Particles of this size may be stable in the atmosphere, but are more likely to join with other particles to form larger particles through agglomeration (join to similar particles to form a homogeneous particle) or conglomeration (join to different particles to form a heterogeneous particle). Sources and Effects
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This note was uploaded on 07/07/2010 for the course CHEM 4602 taught by Professor ... during the Spring '10 term at University of Minnesota Morris.

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PM - Draft-1 - Fgravity FStartAand Water Cleaning Gas and...

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