Are polychlorinated biphenyls water soluble?
In general, PCBs are relatively insoluble in water, and the solubility decreases with increased chlorination (see Table 4-3). PCBs are also freely soluble in nonpolar organic solvents and biological lipids (EPA 1980b).
What is aroclor?
Aroclor is a PCB mixture produced from approximately 1930 to 1979. It is one of the most commonly known trade names for PCB mixtures. For example, the name Aroclor 1254 means that the mixture contains approximately 54% chlorine by weight. Table of Aroclors.
Are PCBs fat soluble?
Polychlorinated biphenyls (PCBs) are considered “persistent organic pollutants;” fat-soluble compounds that bioaccumulate in individuals and bio-magnify in the food chain. These compounds are still present in our food supply (fish, dairy, hamburger, and poultry being the most contaminated) and our bodies.
How many chlorine atoms does an Aroclor 1254 molecule contain?
belongs to the class of organic compounds known as polychlorinated biphenyls. These are organic compounds containing at least two chlorine atoms attached to either benzene ring of the biphenyl moiety. Oily liquids or solids that are colorless to light yellow.
Does water dissolve PCBs?
PCBs tend not to evaporate or to dissolve easily in water. However, they are very soluble in fat and similar substances, which explains why PCBs can build up in animal fat and along the food chain.
How do PCBs get into water?
Fish and small organisms can absorb PCBs from the water and sediments in their habitat. The PCBs accumulate in the food chain when bigger fish consume contaminated smaller fish or organisms. The contamination is passed up the food chain and can reach levels thousands of times higher than the actual levels in the water.
How does the body get rid of PCBs?
The main PCB elimination routes are through the faeces, urine, and breast milk. Once in the gastrointestinal tract, ingested PCBs diffuse across cell membranes and enter blood vessels and the lymphatic system.
Why are Aroclor 1254 and 1260 a challenge?
Aroclors 1254 and 1260 present a particular challenge for bioremediation because they consist of dozens of highly chlorinated congeners that have low bioavailability and are not susceptible to aerobic biodegradation. Thus, anaerobic dechlorination is the primary biological mechanism that controls the fate of these compounds.
Why is Aroclor 1254 a challenge for bioremediation?
PCB sediment contamination often consists of a complex mixture of one or more commercial Aroclors. Aroclors 1254 and 1260 present a particular challenge for bioremediation because they consist of dozens of highly chlorinated congeners that have low bioavailability and are not susceptible to aerobic biodegradation.
Which is the best example of an Aroclor?
Example Aroclors produced included Aroclor 1242, 1248, 1254, and 1260, among other Aroclors. Specific Aroclors carried a four-digit reference number (e.g., Aroclor 1242, 1248, 1254, and 1260)]
How many chlorine atoms are in an Aroclor?
PCBs (commonly called Aroclors) are organic compounds with 1–10 chlorine atoms attached to biphenyl (209 distinct congeners, Figure 5 ). They were widely used as dielectric fluids in transformers, capacitors, and coolants.
