OF THE DRY DEPOSITION PROCESS

THIS PROJECT IS TO DEVELOP TECHNIQUES AND EQUIPMENT FOR DISPERSING LARGE QUANTITIES OF SUBMICRON PAR- TICULATE AEROSOLS INTO THE ATMOSPHERE TO TRACE THE MOVEMENTS OF SOLID-STATE PARTICULATE POLLUTANTS. SUCH POLLUTANTS OFTEN FORM IN THE EXHAUST PLUMES FROM COAL-FIRED ELECTRIC GENERATING PLANTS AND, WHEN <1 MICRON IN SIZE, CAN BE TRANSPORTED FOR LONG DISTANCES. THE MECHANISMS BY WHICH PARTICULATE POLLUTANTS ARE TRANSPORTED AND EVENTUALLY DEPOSITED ON THE GROUND ARE NOT WELL UNDERSTOOD. ONE SUCH DEPOSITION MECHANISM IS COMMONLY REFERRED TO AS ACID RAIN. FIELD STUDIES OF TRANSPORT AND DEPOSITION PROCESSES WILL BENEFIT GREATLY FROM AN INEXPENSIVE TRACER, THAT CAN MODEL THE BEHAVIOR OF THESE PAR- TICULATE POLLUTANTS. THE TRACER WILL CONSIST OF IN- ORGANIC PARTICLES (CARRIERS) OF THE APPROPROATE SIZE DOPED WITH SELECTED ELEMENTS TO ALLOW CLEAR IDEN- TIFICATION. GREATER THAN 75% BY WEIGHT OF THE CARRIER MATERIAL WILL BE ABOUT 0.1 TO 1.0 MICRON IN SIZE. DOPANTS WILL BE SELECTED BASED UPON ENVIROMENTAL SAFETY, DETECTABILITY, COST, AND LOW CONCENTRATION IN THE NATURAL B BACKGROUND. THE CARRIER WILL BE DISPERSED IN WATER, AND THEAND THE DOPANT WILL BE ADDED TO THIS SLURRY AS A SOLUBLE SA SALT. THE AEROSOL WILL BE GENERATED FROM THEE DOPED SLURRY.METHODS WILL BE ESTABLISHED FOR DISPERSING CARRIERS IN WATER; CANDIDATE DOPANTS WILL BE SELECTED AND TESTED; THE MAXIMUM CONCENTRATION OF DOPANT RESULTING IN AN ACCEPTABLE AEROSOL WILL BE DETERMINED; ACHIEVABLE DOPANT CONCENTRATIONS IN THE TRACER PARTICLES WILL BE DETERMINED AND THE PARTICLE SIZE DISTRIBUTION OF THE FINAL AEROSOL WILL BE DETERMINED. ESTIMATES WILL BE MADE OF AEROSOL GENERATION RATES THAT CAN BE ACHIEVED BY SCALE-UP OF THE PROCESS.