Definition - What does Chlorinated hydrocarbons mean?
Chlorinated hydrocarbons are composed of carbon, chlorine, and hydrogen, and are insoluble in water. They are specific hydrocarbon molecules that have atoms of chlorine chemically bonded to them, the number of which partly determines the properties of the molecule. The chemical and physical properties are determined by the number of carbon atoms and how they are arranged in three-dimensions.
The wide variation of chlorinated hydrocarbons also has a wide set of applications that are economically important, making it the most important industrial organic compound. The chlorinated hydrocarbon produced after refining crude oil comprises synthetic rubber which is used to manufacture tires for automobiles, plastics, pipes, furniture, toys, etc. They can also be used for anesthetics, industrial solvents, and precursors for the production of Teflon.
Chlorinated hydrocarbons are highly potent and environmentally persistent insecticides. When combined with fluorine, they form chlorofluorocarbons (CFC) that are used as a refrigerant. However, chlorine, which is used as a disinfectant in wastewater treatment, has the possibility to form harmful chlorinated hydrocarbons. Sewer gas has been found to contain chlorinated hydrocarbons in addition to other contaminants like alkanes and small aromatic compounds. Chlorine even at low concentrations is toxic to fish and other aquatic life forms.
Trenchlesspedia explains Chlorinated hydrocarbons
Hydrocarbons are entirely made of hydrogen and carbon atoms derived from carbon-based fossil fuels like coal and petroleum. Chlorinated hydrocarbons are specific hydrocarbon molecules that contain chlorine atoms chemically bonded to them. The properties of the molecule are determined in part by the number of chlorine atoms bonded to a specific chlorinated hydrocarbon.
The chemical and physical properties of chlorinated hydrocarbons are also determined by the number and arrangement of carbon atoms in three dimensions. When crude oil is refined it produces chlorinated hydrocarbons create synthetic rubbers and plastic that are used for the manufacture of a variety of everyday things. Chlorinated hydrocarbons are considered among the most important industrial organic compounds.
Degradation of Chlorinated Hydrocarbons
Chlorinated hydrocarbons are environmentally persistent, hence it is necessary to have methods to clean up areas contaminated by them. Various methods to get rid of chlorinated hydrocarbons are being developed by scientists. One such is the use of genetic engineering to develop microorganisms that can help degrade them or plants that can absorb them from the contaminated soil. Environmental conditions that support the natural reduction of chlorinated compounds include:
- Microorganisms that can degrade contaminants
- The oxidation-reduction capacity of the groundwater
- Sufficient electron donors
- Absence of competing electron acceptors
Chlorinated hydrocarbons such as dichlorodiphenyltrichloroethane (DDT) are potent pesticides. It was first used during World War II to control lice infestation in allied troops. This success led to its extensive use to control insects that spread yellow fever, malaria, typhus, and plague.
However, its overuse led to the development of DDT resistant insects and it was found that toxic levels were accumulating in the fatty tissues of fish, birds, mammals, and even in humans. This led to a ban on its use in several countries in spite of its effectiveness. Other insecticides include chlordane, aldrin, mirex, and toxaphene.
Like chloroform and carbon tetrachloride, another compound closely related to chlorinated hydrocarbons is Chlorofluorocarbons (CFCs). They are single carbon atoms with chlorine and fluorine bonded to them. widely used CFCs are Freon 11 (trichlorofluoromethane) and Freon 12 (dichlorodifluoromethane) which are used as refrigerants and propellants and are odorless, non-flammable, and stable compounds. Since they are believed to affect the ozone layer, they are being slowly phased out.