Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Hydrocarbons plant pollutant

It appears that a permanent solution to the world energy problem, dramatic reduction of biospheric hydrocarbon combustion pollution, and eliminating the need for nuclear power plants (whose nuclear component is used only as a heater) could be readily accomplished by the scientific community [18]. However, to solve the energy problem, we must (1) update the century-old false notions in electrodynamic theory of how an electrical circuit is powered and (2) correct the classical electrodynamics model for numerous foundations flaws. [Pg.643]

Hydrocarbons. Extensive pollution of air occurs from the introduction of hydrocarbons either from (a) the incomplete combustion of hydrocarbon fuels in both stationary and vehicular engines or (b) from paint spraying, solvent cleaning, printing, chemical and metallurgical, and other plants that... [Pg.1328]

Ozone, known for its beneficial role as a protective screen against ultraviolet radiation in the stratosphere, is a major pollutant at low altitudes (from 0 to 2000 m) affecting plants, animals and human beings. Ozone can be formed by a succession of photochemical reactions that preferentially involve hydrocarbons and nitrogen oxides emitted by the different combustion systems such as engines and furnaces. [Pg.261]

Cement plants in the United States are now carehiUy monitored for compliance with Environmental Protection Agency (EPA) standards for emissions of particulates, SO, NO, and hydrocarbons. AH plants incorporate particulate collection devices such as baghouses and electrostatic precipitators (see Air POLLUTION CONTROL methods). The particulates removed from stack emissions are called cement kiln dust (CKD). It has been shown that CKD is characterized by low concentrations of metals which leach from the CKD at levels far below regulatory limits (63,64). Environmental issues continue to be of concern as the use of waste fuel in cement kilns becomes more widespread. [Pg.295]

An extensive source of natural pollutants is the plants and trees of the earth. Even though these green plants play a large part in the conversion of carbon dioxide to oxygen through photosynthesis, they are still the major source of hydrocarbons on the planet. The familiar blue haze over forested areas is nearly all from the atmospheric reactions of the volatile organics... [Pg.74]

The behavior of these pollution roses is intuitively plausible, because considerable hydrocarbon emissions come from motor vehicles which are operated in both winter and summer and travel throughout the urban area. On the other hand, sulfur dioxide is released largely from the burning of coal and fuel oil. Space heating emissions are high in winter and low in summer. The SO2 emissions in summer are probably due to only a few point sources, such as power plants, and result in low average concentrations from each direction as well as large directional variability. [Pg.360]

The most widespread and persistent urban pollution problem is ozone. The causes of this and the lesser problem of CO and PMjq pollution in our urban areas are largely due to the diversity and number of urban air pollution sources. One component of urban smog, hydrocarbons, comes from automobile emissions, petroleum refineries, chemical plants, dry cleaners, gasoline stations, house painting, and printing shops. Another key component, nitrogen oxides, comes from the combustion of fuel for transportation, utilities, and industries. [Pg.397]

The increasing number of atomic reactors used for power generation has been questioned from several environmental points of view. A modern atomic plant, as shown in Fig. 28-3, appears to be relatively pollution free compared to the more familiar fossil fuel-fired plant, which emits carbon monoxide and carbon dioxide, oxides of nitrogen and sulfur, hydrocarbons, and fly ash. However, waste and spent-fuel disposal problems may offset the apparent advantages. These problems (along with steam generator leaks) caused the plant shown in Fig. 28-3 to close permanently in 199T. [Pg.451]

A further application of the manipulation of microbial activity in the rhizo-sphere is their potential to remediate contaminated land. Bioremediation involves the u.se of microorganisms that break down contaminants. Radwan et al. (255) found that the soil associated with the roots of plants grown in soil heavily contaminated with oil in Kuwait was free of oil residues, presumably as a result of the ability of the resident rhizosphere microflora to degrade hydrocarbons. The use of plants as a means to accumulate pollutants such as heavy metals (256,257) to degrade hydrocarbons and pesticides (255) is already widely implemented and has proven to be successful. In some cases, there is no doubt that it is the plant itself that is responsible for the removal of the contaminants. However, in most... [Pg.125]

Heit, M. 1985. The relationship of a coal fired power plant to the levels of polycyclic aromatic hydrocarbons (PAH) in the sediment of Cayuga Lake. Water, Air, Soil Pollut. 24 41-61. [Pg.1400]

Thomas, W., A. Ruhling, and H. Simon. 1984. Accumulation of airborne pollutants (PAH, chlorinated hydrocarbons, heavy metals) in various plant species and humus. Environ. Pollut. 36A 295-310. [Pg.1408]

TeRRox A process for decontaminating soil which has been polluted by hydrocarbons by treating it with hydrogen peroxide. Developed by DeGussa and operated at its plant in Knapsack, Germany, from 1996. [Pg.266]

Air pollution in cities can be considered to have three components sources, transport and transformations in the troposphere, and receptors. The sources are processes, devices, or activities that emits airborne substances. When the substances are released, they are transported through the atmosphere, and are transformed into different substances. Air pollutants that are emitted directly to the atmosphere are called primary pollutants. Pollutants that are formed in the atmosphere as a result of transformations are called secondary pollutants. The reactants that undergo the transformation are referred to as precursors. An example of a secondary pollutant is troposphere ozone, O3, and its precursors are nitrogen oxides (NO = NO + NO2) and non-methane hydrocarbons, NMHC. The receptors are the person, animal, plant, material, or urban ecosystems affected by the emissions (Wolff, 1999). [Pg.232]

Losses of valuable components through waste streams The chemical analysis of various plant exit streams, both to the air and water, should indicate if valuable materials are being lost. Adjustment of air-fuel ratios in furnaces to minimize hydrocarbon emissions and hence fuel consumption is one such example. Pollution regulations also influence permissible air and water emissions. [Pg.8]

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic compounds which are absorbed by the cuticular wax layer, which acts as a trap for these pollutants. Plants experiencing PAEI exposure (for example, on the verges of roads carrying heavy traffic) often show an increased level of wax... [Pg.167]


See other pages where Hydrocarbons plant pollutant is mentioned: [Pg.290]    [Pg.24]    [Pg.281]    [Pg.24]    [Pg.345]    [Pg.212]    [Pg.275]    [Pg.1541]    [Pg.350]    [Pg.452]    [Pg.251]    [Pg.67]    [Pg.326]    [Pg.477]    [Pg.652]    [Pg.46]    [Pg.711]    [Pg.748]    [Pg.101]    [Pg.104]    [Pg.271]    [Pg.50]    [Pg.15]    [Pg.275]    [Pg.1341]    [Pg.229]    [Pg.224]    [Pg.818]    [Pg.132]    [Pg.108]    [Pg.132]    [Pg.80]    [Pg.80]    [Pg.82]    [Pg.83]    [Pg.230]   
See also in sourсe #XX -- [ Pg.74 ]




SEARCH



Plants pollutants

Pollutants hydrocarbons

© 2024 chempedia.info