How can aerosols be removed from the atmosphere

The results of the measurements were used to calculate the rate of removal of particles in the vicinity of growing cloud droplets. This is a preview of subscription content, access via your institution. Rent this article via DeepDyve.

Aitken J. Cawood W. Google Scholar. Facy L. Goldsmith P. Geofisica pura e applicata, 50, Article Google Scholar. S, vol. Metnieks A. Bulletin No. Pollak L. Millikan A. Rev, 22, 1 Taylor H. Houghton Henry G. The goal of the experiment was to determine what, if any, the effect or effects of the station would be on the surrounding atmosphere.

Two supplies were used. The first was made by Matsusaka Corp. All spokes were 0. The central tower and all peripheral spokes had a winching mechanism to allow easy installation and maintenance. Fiberglass bars later replaced by high dielectric strength rope was used as insulation.

Control Unit. The unit was manufactured by Comtrol, Inc. Meteorological data was fed to the 6K-Lite control unit by a commercially available combination thermometer, barometer, anemometer, pluviometer and relative humidity meter. Other Equipment and Resources 1. Current and archival historical weather information including meteorological information, raw weather data and forecasts, satellite imagery, radar imagery, etc.

Real time atmospheric measurements were performed using a modified Piper Comanche B configured to transport instruments on both wingtips. Two optical spectrometers manufactured by Grimm Technologies, Inc. Each spectrometer was equipped with an isokynetic air intake, which was the only part that protruded from the instrument housing, calibrated for the cruise speed of the Comanche, which is knots with the instruments mounted on its wingtips.

The spectrophotometers created an aerodynamic drag. Flight Operations. The basic flight plan Alpha is shown in FIG. The aircraft took off from its base, climbed to cruising altitude, typically 2, feet above ground level AGL or 3, feet AGL, which were the flight altitudes most used. It proceeded to Waypoint 1 and then proceeded to the ionization station Waypoint 2 and then to Waypoint 3.

A few flights had a variation where the airplane would take a course straight East to head for the coast and then return to base. This last variant was only to compare atmospheric conditions in the are of influence of ionization to the atmosphere at the coast. These flight plans are shown in FIG. In Bravo or Charlie flights, the distance to the coast is approximately 86 nautical miles.

The objective of the measurement flight program was to determine what influence, if any, the ionization station had on its surrounding atmosphere. The most useful approach to do this is to measure particle counts and to see what patterns develop in terms of particle counts under each operational state: positive, negative or non-operational zero.

After the first flight it was obvious that we needed to rearrange the data in order to make any sense. The spectrometers measure particle counts in real time every 6 seconds, which means that a flight segment WP 1 to WP 2 to WP 3 will produce about readouts.

Furthermore, they are recording data on 32 channels, one channel for each range of particle size. The overall size range measured by the spectrometers is 0. The second rearrangement was that we divided each flight segment i. Each flight zone is identified in FIG. In the case of Bravo and Charlie flights, we have the ubiquitous 12 flight zones plus another 7 in the track to the coast and an additional flight zone right along the coast.

In all cases, we attempted to wait enough time for the atmosphere to be fully charged by the station 96 hours or to discharge fully after the station was shut down before we made a measurement flight.

We also did not make flights when there was cloud cover within feet of the flight altitude. The atmospheric and weather conditions for each measurement flight date were analyzed to assure the validity of the data obtained. In all cases satellite images were used to determine optical depth, presence of sulfates, dust and smoke and a backward wind trajectory report was obtained for the approximate time of flight to determine wind direction and velocity at the time and altitude of the flight.

The ionization station is represented by a small bar between flight zones 6 and 7. In general terms the slope is negative, which means that the aerosol counts are much higher in Zone 1 than in Zone This flight occurred only 1 day after the previous flight. Comparing flight zones 1 through 12 on this flight, there is a great similarity with the previous flight results, namely, negative slope and much greater aerosol concentrations in zone 1 as compared to zone This slope continues as the aircraft turns East toward the coast and aerosol counts drop until the coast is reached.

This is natural because maritime atmosphere is typically cleaner than continental atmosphere. The further away from the ocean, the greater the aerosol concentration. It is clear that the slope is positive and the aerosol counts in zone 1 are much lower than the counts in zone The results are similar to the negative polarity operation data shown on FIG. This chart clearly shows that on the coast, the aerosol counts are low. They gradually increase the more inland the measurements are taken, until flight zone 11 , where there is a very significant, sharp change in slope and the aerosol counts diminish thereafter until, at zone 1 they are even lower than at the coast.

This is because the first zone to get measured is zone 1. Zone 20 does not get measured until about an hour and a half later and it is a widely accepted fact that the later in the morning, the higher the aerosol counts due to inversion. In order to obtain this figure it was necessary to normalize the flight data, because open atmosphere variability produces overall particle counts with a high degree of variability, with some days exhibiting an average of 5, aerosols per liter and other days recording , aerosols per liter.

All other readings are expressed as a fraction of 1 or as a percentage. It is readily apparent that with no operation the slope is negative, while under operational conditions, the slope is positive and a steeper slope is observed for positive operation than for negative.

This means that positive operation is more efficient in reducing aerosol counts than negative operation. In positive operation, aerosols are catalyzed to grow and the increased mass increases their vertical velocity to ground due to gravitation. Near ground, positively charged aerosols are further attracted to ground which has a negative charge due to electrical attraction.

Therefore, aerosol deposition to ground under the positive operational mode is the result of adding electrical deposition to gravitational deposition.

In the case of negative operation, total deposition is the result of gravitational deposition less the electrical repulsion of negative aerosol by the negatively charged ground. In order to view the full impact of the capability of the ionization station to reduce the aerosol counts, FIG. The curve for zero operation non operational shows that the aerosol counts go from an index of 1 in zone 12 and they gradually increase to approximately an index of 1.

When the operational state is negative, the zone 12 index of 1 decreases to about 0. In other words, the station, operating in positive mode, decreases what would be a normal index of 1. Although the subject invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciated that changes or modifications thereto may be made without departing from the spirit or scope of the subject invention as defined by the appended claims.

The entire contents of all patents, published patent applications, and other references cited herein are hereby expressly incorporated herein in their entireties by reference. Yu, Turco From molecular clusters to nanoparticles, J. Hakone VIII, , p. All rights reserved. Login Sign up.

Search Expert Search Quick Search. Methods of removing aerosols from the atmosphere. United States Patent An antenna is disclosed to efficiently ionize the atmosphere for the purpose of reducing the aerosol counts, and therefore the number of poluted particles in suspension in the atmosphere, by deposition to ground.

The antenna includes peripheral nodes and a central node. Each of the peripheral nodes is connected to adjacent peripheral nodes through peripheral spokes. The peripheral nodes are also connected to the central node through radial spokes.

Electric power is applied to the peripheral spokes and the radial spokes causing the antenna to charge the atmosphere through the emission of ions. The antenna minimizes an attenuation factor that reduces ionization efficiency and reduces the land requirements for its installation. Click for automatic bibliography generation. Ionogenies Corp. Download PDF I claim: 1. The antenna of claim 1 wherein said antenna is capable of electrically charging the atmosphere for reducing the aerosol counts through deposition to ground, upon application of a selected, steady state power level having a voltage value of between about zero volts and about positive kilovolts and between about zero volts and about negative kilovolts and having a current value of between about zero and about five amps.

The antenna of claim 1 wherein the central node comprises: a central base portion; and a central vertical member coupled to the base portion. The antenna of claim 3 wherein the central vertical member includes a mechanism for bringing the radial spokes connected to the central node from a first position to a second position.

Laboratory workers should learn and follow as appropriate these practices. Using a combination of the appropriate safety equipment and safe procedures is the primary method to minimize the creation of and exposure to aerosols.

Laboratory Safety. Search sitewide:. Preventing Aerosol Production. Laboratory Safety Biosafety Preventing Aerosol Production Aerosols are liquid and solid particles suspended in the air. A certified biological safety cabinet class I or II is the primary barrier to protect worker from aerosols if working with RG2 or higher agents. Other safety devices include safety centrifuges with automatic locking mechanisms or solid lids, safety centrifuge cups, safety blenders, safety sonicators. Vacuum line trap and filter systems are used to protect the vacuum system from aerosols.

Routinely inspect centrifuge to ensure that leakage is not occurring. Do not overfill centrifuge tubes. Wipe the outside of the tubes with disinfectant after they are filled and sealed. Centrifugation may be performed in a centrifuge that is contained within a specially designed biological safety cabinet or other physical containment device.

If a whole centrifuge containment device is not available, internal aerosol containment devices e.