Does PCE degrade to TCE?
The degradation process for PCE is generally PCE→TCE→cis-1,2-DCE (with the possibility of minor amounts of trans-1,2-DCE and 1,1-DCE)→VC→ethene.
What does TCE degrade into?
However, in general, the less chlorinated the compound, the more amenable it is to aerobic biodegradation. Thus, TCE can degrade anaerobically or sometimes aerobically; vinyl chloride will biodegrade under aerobic conditions as well as under highly reducing conditions (56).
How is TCE treated in groundwater?
TCE usually is remediated through pump and treat, using either air stripping or granular activated carbon, but there are many innovative cleanup methods—physical, chemical, thermal, and biological—that have been applied successfully to remove TCE from soil and ground water or to convert it into nonhazardous compounds.
How does TCE get into groundwater?
TCE is a volatile solvent used for degreasing during the manufacture of products. TCE can enter soil, groundwater, and surface water from leaking storage tanks or from improper disposal of wastes. Once TCE reaches groundwater aquifers, it can contaminate private and public drinking water wells.
What are the breakdown products of PCE?
The dechlorination or degradation process produces daughter products as it works toward non-regulated non-toxic compounds. The primary daughter products include trichloroethylene (TCE), cis-1,2-dichloroethylene (cis-DCE), trans-1,2-dichloroethylene (trans-DCE), and vinyl chloride (VC).
What is the meaning of PCE?
personal consumption expenditures
The “core” PCE price index is defined as personal consumption expenditures (PCE) prices excluding food and energy prices. The core PCE price index measures the prices paid by consumers for goods and services without the volatility caused by movements in food and energy prices to reveal underlying inflation trends.
What is TCE used for?
It is used primarily to make refrigerants and other hydrofluorocarbons and as a degreasing solvent for metal equipment. TCE is also used in some household products, such as cleaning wipes, aerosol cleaning products, tool cleaners, paint removers, spray adhesives, and carpet cleaners and spot removers.
How do you remove TCE from drinking water?
Treatment options are available to remove trichloroethylene from well water. The most commonly used option is granular activated carbon filtration. 1 Options include central treatment (at the well or at entry to home) or a point-of-use device (kitchen sink filter).
How do you detect TCE?
If you have been exposed to TCE recently, it can be detected in your breath, blood, or urine. For small amounts of TCE, breath testing must occur within an hour or two after exposure. For large amounts of TCE, blood and urine tests can find TCE and its byproducts up to a week after exposure.
How do you avoid TCE?
People who work with or near TCE should wear protective equipment and minimize exposure to the chemical. In general, people should avoid drinking water known to be contaminated with TCE, and children should be prevented from playing in areas where the chemical has been found in the soil.
Is TCE still used?
In December 2016, using its authority under the newly strengthened Toxic Substances Control Act (TSCA), EPA proposed to ban the use of trichloroethylene (TCE) in aerosol degreasing and spot cleaning in dry cleaning facilities, after finding excessive risks to workers, consumers, and bystanders.
What is aerobic dechlorination?
10.3. Under anaerobic conditions, dechlorination is the removal of one or more chlorine substitutions on the PCB molecule (dechlorination is a minor factor in systems that are mostly aerobic). Figure 10.10 shows some of these example dechlorination processes.