Showing papers on "Particulates published in 1971"

Apparatus for sensing particulate matter

Abstract: Apparatus for sensing particulate matter in a gas stream and having a sampling probe tube with a Pitot tube for measuring the velocity of the gas stream. A Venturi arrangement is provided inside the probe tube for measuring the velocity of the sample stream taken by the probe, so that the two velocities can be matched to provide isokinetic sampling. The sensor used is a pair of coaxial electrodes and the sensor includes an arrangement for mixing air into the sample stream adjacent the electrodes to minimize deposition of the particulate matter from stagnant volumes of gas.

Particulate and dissolved organic matter in the amerasian basin of the arctic oceans1

Abstract: Vertical profiles for total particulate matter, particulate organic carbon, particulate organic nitrogen, and dissolved organic carbon were determined along with supporting hydrographic and chemical parameters in the Amerasian Basin of the Arctic Ocean.

Radiative Effects of Pollutants in the Atmospheric Boundary Layer

Abstract: The effect of pollutants, both gaseous and particulate, on the air temperature in the boundary layer is examined by computing their interaction with solar and infrared radiation. Carbon dioxide and large concentrations of ozone are found to be the most important gaseous IR absorbers. Nitrogen dioxide and high concentrations of SO2 and O3 produce important heating by absorption of solar radiation. The effect of particles on the solar and IR radiative heating rates computed for realistic numbers, size distributions and complex refractive indexes is found to approach or exceed the heating rates due to water vapor.

Ddt residues in seawater and particulate matter in the california current system

Abstract: Continuous samples of seawater and organic particulate material collected along linear transects in the California current system were analyzed for DDT residues. DDT residue concentrations in whole seawater, as determined by continuous-flow, liquid-liquid extraction, ranged from 2.3 X 10- 12 glml off Oregon and Washington, to 5.6 X 10- 12 glml off southern California. Geographical patterns in these concentration values are discussed in relation to mechanisms of land-sea DDT residue transfer. DDT residue concentrations in particulate material collected by continuous-flow centrifugation and filtration of the centrifugal pellet onto GFC-glass-fiber filters, ranged from 1.2 to 5.7 X 10-6 gig carbon (with one exception). These values were related to the density of the standing crops. DDT residues in this particulate fraction accounted for less than 10% of the DDT residues in the whole seawater samples. Residues which are fixed to particles of less than 1-2 f' in diameter may account for the balance of the DDT residues in the whole water samples. Experimental results are described which implicate adsorp­ tion as the uptake mechanism for algal cells; these experiments also support the idea that <1-2 f' di­ ameter particles carry most of the DDT residues in whole seawater. DDT and its metabolites have dispersed into the ocean and are found in high concentrations in the predators of oceanic food chains. Theoret­ ical considerations predict a net transfer of extant DDT residues to the oceans, via atmos­ pheric and river currents (Smith, 1970). In view of the well-known chemical stability of the principal constituents of the DDT complex, p,p'­ DDT, DDD, and especially DDE, it is not sur­ prising that levels of DDT residues in marine plankton samples have risen during the past de­ cade (Cox, 1970a). No published data are avail­ able, however, on concentrations of DDT residues in seawater and in oceanic particulate matter. Chlorinated pesticides have been found in con­ centrations up to 13 X 10- 9 g/ml in surface slicks in Biscayne Bay, Fla., and at concentra­ tions of about -12 glml in the surrounding waters (Seba and Corcoran, 1969). Measurements of DDT concentration in the open ocean are needed to construct a systematic account of DDT residue transport to the pelagic environment of the ocean, and to estimate. the ultimate transport of DDT residues to the sediments.

Method and apparatus for sensing substances by analysis of adsorbed matter associated with atmospheric particulates

Abstract: A method and apparatus for sensing substances, such as mineral deposits, in which atmospheric particulates in an area being investigated are collected, and adsorbed matter is removed from the particulates. The adsorbed matter (usually in the gaseous state) is then analyzed to provide information concerning the possible existence of the substance in the area being investigated.

Particulate Air Pollution In the United States

Abstract: A study was conducted to identify, characterize, and quantify the national particulate air pollution problem from stationary sources. Particulate emissions from stationary sources were determined from data on emission factors, grain loadings, and material balances. The principal method used for establishing the tonnage emitted by an industry utilized uncontrolled emission factors. Total tonnage emitted by a given industry was calculated from four quantities: (1) an emission factor for the uncontrolled source; (2) the total tonnage processed per year by the industry; (3) the efficiency of control equipment used; and (4) the percentage of production capacity equipped with control devices. Particulate emissions from stationary sources in the United States currently total approximately 18 X 106 ton/yr. The major stationary sources of particulates include electric power generation plants, the crushed stone industry, the forest products industry, agriculture and related operations, the cement industry, and the ...

Removal of heavy metals from aqueous solutions

Abstract: Heavy metals dissolved in aqueous streams are removed by contacting the aqueous stream with a polyelectrolyte in the presence of particule matter, allowing the heavy metal to be bound to the particulate matter and separating the particulate matter containing the heavy metal from the aqueous stream, thereby purifying it.

Observations on the Concentration of iron in Sea Water, With Particular Reference to Southampton Water

Abstract: Determinations have been made of paniculate iron in samples collected from Southampton Water over a period of 2 years. Concentrations of 106–1046 ug/l. were found. Total amounts of paniculate matter ranged from 1·3 to 48·6 mg/1., of which iron constituted 0–5–14%. Amounts of paniculate matter and paniculate iron showed a highly significant correlation. For one station where wind-speed data were available there was a highly significant correlation between the amount of particulate matter and the mean daily wind speed for the 4 days prior to sampling. No clearly defined seasonal variation in the amounts of particulate matter or particulate iron was found. The concentration of particulate iron in the estuary appeared to be dominantly controlled by meteorological and hydrological factors.

Fog impingement scrubbing system

Abstract: A fog impingement scrubber system is provided for removing from an air stream particulate matter, such as product dust and combustion dust products, as well as fumes, and water soluble or water reactant vapors generated during a manufacturing process. The polluted air stream from the manufacturing process is fed to a fog impingement scrubber system. The polluted air stream is first sprayed by a series of high pressure water sprays to create a fog or mist to dampen or wet particulate matter in the air stream, particularly any fine or microscopic sized particles. A second set of water nozzles or sprays is then utilized further downstream of the fogging area to moisten the larger particles of particulate matter in the air stream. The sprayed polluted air stream is then impinged upon a whirlpool provided in the scrubbing system, where the moistened particles are removed from the air stream, and where the water soluble or water reactant vapors are treated. Any moisture in the air is then removed by a demisting system, and the clean air then discharged back to the atmosphere.

Gas cleaning apparatus

Abstract: Gas cleaning apparatus having at least two stages In the first stage the gas is passed through a liquid spray for removing particulate material In the second stage any remaining particulate matter or droplets are removed The stages involve combinations of slotted baffles with deflectors for stripping the gas and bonnet units with concentric passages for reversal of flow for removing particulate matter by centrifugal action and by impingement

Method for inducing agglomeration of particulate in a fluid flow

Abstract: A method of facilitating removal of particulate from a fluid stream whereby individual particles of the particulate are agglomerated to form larger and therefore more easily removable particles. The particulate is passed through a zone which contains electric charging regions disposed at locations transversely spaced across the fluid stream and adapted to charge the particulate. Charge regions are alternately charged across the stream; that is, contiguous charge regions contain oppositely polarized electric fields, thereby to create transverse to the stream small regions where the particulate is charged positive, say, immediately adjacent to regions where it is charged negative. The thusly charged particles are then mixed to bring the oppositely charged particles into close proximity, one with the other, and small particles of the particulate agglomerate upon larger particles. The agglomerated particulate is then precipitated or otherwise removed from the fluid.

Gaseous Iodine Measurements and Their Relationship to Particulate Lead in a Polluted Atmosphere

Abstract: Gaseous iodine and particulate iodine and lead samples were collected simultaneously in a polluted atmosphere using activated charcoal and membrane filters. Concentrations of gaseous iodine varied from 10–18 ng m−3 and particulate iodine from 2–15 ng m−3 as determined by neutron activation analysis. The total iodine concentration found in this work is approximately twice that found in the unpolluted marine atmosphere. Lead concentrations varied from 0.4–3.7 µg m−3 as determined by atomic absorption spectrophotometry. There is an apparent relationship between the concentration of total particulate matter in the air and the ratio of particulate iodine to gaseous iodine. This relationship is consistent with laboratory investigations of gaseous I2 adsorption onto combustion aerosols reported by other investigators. Calculations indicate that the concentrations of gaseous iodine measured in this work should be sufficient to activate all lead containing particles to ice nuclei in a polluted atmosphere....

Dust abatement device and method of dust abatement

Abstract: A dust abatement device including an intake or collecting means for delivering air to a rotating fan constituting a propulsion means, and outlet means directing air from the fan in a curtain at an area of dust concentration to inhibit dust movement out of the area. The intake means includes a duct extending from the fan to the area of dust concentration to pick up and deliver air-borne dry dust particulate from such area to the fan, the fan mixing the dry dust particulate with liquid sprayed on the fan to provide a slurry, and the outlet means directing the air and slurry from the fan to the area of dust concentration so that the slurry further wets the dust particulate at such area. The dust abatement device can be mounted on a machine that includes a mechanism for acting on material in a manner so as to create the area of dust concentration. More particularly, the dust-forming mechanism can be the cutter head of a continuous mining machine that rotates in a direction to cause an air flow rearwardly and upwardly from the area of dust concentration. In this event, the fan delivers the air and slurry in a spray to the cutter head and substantially in a direction counter to the air flow created by the cutter head to retard such flow and movement of the dry dust particulate away from the area of dust concentration.

Microscopic determination of iron-organic aggregates in sea and lake waters

Abstract: The size distribution and the aggregation state of particulate organic matter and particulate iron were microscopically observed by the application of histological dyeing method. They were seriously affected by the seasonal water circulation in Lake Haruna. From the results, the formation and the change of particulate iron were suggested. Iron-organic aggregates were observed both in the lake and in the sea, and the significance of their distribution was discussed in relation to the sedimentation of iron and the formation of organic aggregates.

patterns and trends in levels of suspended particulate matter

Abstract: The National Air Surveillance Network (NASN) has collected samples of suspended particulate matter since 1957. These data values are graphically summarized by the application of Whittaker-Henderson Type A curve-smoothing formulas to 10 years of data. Fifty-eight urban sites and 20 nonurban sites are studied by this technique, which permits an intuitive grasp of the underlying cyclical patterns as well as long-term trends in nationwide levels of suspended particulate matter. Seasonal patterns are evident for many urban and nonurban sites, although sharp contrasts in seasonal characteristics exist between the two types of sites. Long-term levels tend slightly downward at many urban locations, but the opposite effect is observed at many nonurban sites.