Fouling


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fouling

[′fau̇l·iŋ]
(chemical engineering)
Deposition on the surface of a heat-transfer device of sediment in the form of scale derived from burned particles of the heated substance.
(naval architecture)
The adhesion of different marine organisms to the underwater parts of ships, causing the ships to lose speed.
(ordnance)
The deposit that remains on the bore of a gun after firing.

Fouling

 

the settling of aquatic organisms in water-intake pipes and on rocks and stones, buoys, underwater cables, port and other hydrotechnical structures, and the bottom of ships.

The principal fouling organisms are sessile animals and plants—for example, cirripeds (acorn barnacles and goose barnacles), bivalve mollusks (mussels), hydroids, mosses, sponges, ascidians, Sedentaria, and algae. Motile animals, primarily worms and crustaceans, settle among the sessile organisms. One of the most important components of fouling are bacteria, which generally settle first on unfouled surfaces.

The majority of fouling organisms, as a result of reproduction, produce spores or planktonic larvae, which are distributed by currents and subsequently settle on a substrate, where they transfer to a sessile way of life. Marine fouling is more varied and extensive (up to 100 or more kg per sq m) than freshwater fouling. Fouling animals generally feed on tiny food particles, which they filter out of or capture in the water.

There are many known cases of fouling organisms being extensively distributed by means of ships. For example, after the completion of the Volga-Don Canal, more than 20 species of invertebrates and algae were transferred on the bottom of ships from the Sea of Azov to the Caspian Sea, where the organisms settled.

Fouling decreases the speed of ships and impedes the flow of water in pipes leading to industrial enterprises. It also cuts down on the efficiency of cooling installations. Fouling adds to the exposure of piers and docks to the action of waves, and it promotes the corrosion of metal and concrete underwater structures.

Control measures include cleaning fouled surfaces regularly, rinsing water pipes with hot water or chemical solutions that are toxic to fouling organisms, and covering overgrown surfaces with poisonous paints.

REFERENCES

Morskoe obrastanie i bor’ba s nim. Moscow, 1957. (Translated from English.)
Morskie obrastaniia i drevolochtsy. Moscow, 1961. (Trudy Instituta okeanologii AN SSSR, vol. 49.)
Morskie obrastaniia i drevotochtsy. Moscow, 1963. (Trudy Instituta okeanologii AN SSSR, vol. 70.)
Morskoe obrastaniia. Moscow, 1967. (Trudy Instituta okeanologii AN SSSR, vol. 85.)
Zevina, G. B. Obrastaniia v moriakh SSSR. Moscow, 1972.

G. M. BELIAEV

References in periodicals archive ?
The barrel's never shown more than the faintest hint of copper fouling and after cleaning shoots worse for a group or two before returning to normal.
Although the same study (Olufade and Simonson 2018) also proposed the application of indirect methods to detect the onset of fouling and assessed the effect of moisture transfer rate through membranes on crystallization fouling in LAMEEs, only one desiccant solution (Mg[Cl.sub.2](aq)) was used in the experiments reported.
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Subsequently, the ZnS layer easily bonds to other organic materials diffusing from the rubber during a molding cycle, and thus leads to mold fouling after many molding cycles.
Coun Liz Simpson, chairwoman of the Safer Northumberland Partnership, said: "Dog fouling and littering are real public health problems and a blight on the environment.
To report issues of dog fouling |in Denbighshire contact the council's customer contact centre on 01824 706100 (Welsh Language line), 01824 706101 (English language line) or report it online at denbighshire.gov.uk.
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They include the possibility of using a private company to issue fines for littering and dog fouling, giving traffic wardens additional powers to issue such fines, and a city-wide campaign to raise awareness of the problem.
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I would urge Middlesbrough Council to increase the fixed penalty fines for dog fouling and litter louts to pounds 100.