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The sublimation that occurs at the solid-gas boundary (critical sublimation point) (corresponding to boiling in vaporization) may be called rapid sublimation, and the substance sublimes rapidly. The words "gradual" and "rapid" have acquired special meanings in this context and no longer describe the rate of sublimation. [citation needed]
Water vapor can also be indirect evidence supporting the presence of extraterrestrial liquid water in the case of some planetary mass objects. Water vapor, which reacts to temperature changes, is referred to as a 'feedback', because it amplifies the effect of forces that initially cause the warming. Therefore, it is a greenhouse gas. [2]
A sublimatory [1] [2] or sublimation apparatus is equipment, commonly laboratory glassware, for purification of compounds by selective sublimation. In principle, the operation resembles purification by distillation , except that the products do not pass through a liquid phase .
A practical definition of water pollution is: "Water pollution is the addition of substances or energy forms that directly or indirectly alter the nature of the water body in such a manner that negatively affects its legitimate uses." [1]: 6 Water is typically referred to as polluted when it is impaired by anthropogenic contaminants.
Water pollution (or aquatic pollution) is the contamination of water bodies, with a negative impact on their uses. [153]: 6 It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come ...
Thermal pollution can also be caused by the release of very cold water from the base of reservoirs into warmer rivers. When water used as a coolant is returned to the natural environment at a higher temperature, the sudden change in temperature decreases oxygen supply and affects ecosystem composition. Fish and other organisms adapted to ...
where water tables are shallow, the irrigation applications are reduced. As a result, the soil is no longer leached and soil salinity problems develop; stagnant water tables at the soil surface are known to increase the incidence of water-borne diseases like malaria, filariasis, yellow fever, dengue, and schistosomiasis (Bilharzia) in many ...
Nutrient pollution, a form of water pollution, refers to contamination by excessive inputs of nutrients. It is a primary cause of eutrophication of surface waters, in which excess nutrients, usually nitrates or phosphates, stimulate algae growth. Such blooms are naturally occurring but may be increasing as a result of anthropogenic inputs or ...