How do you remove PCE from groundwater?

Remediating Groundwater Technologies for cleaning up PCE-contaminated groundwater include pump and treat, in situ bioremediation using injection of reducing compounds to promote bacterial breakdown of the chlorinated compounds, chemical oxidation, permeable reactive barriers (PRBs), and air sparging/SVE.

What does PCE break down into?

In air, PCE breaks down very slowly, and as a result, can travel a long distance. It does not easily degrade in soil either, but over time, can break down into other chemicals such as vinyl chloride. In groundwater or soil, it can also volatilize into a gas and enter buildings through tiny cracks in the foundation.

What is PCE in groundwater?

PCE is an organic chemical introduced in the environment by human activity. Thus, its detection in an environmental sample (e.g., groundwater, surface water, soil, indoor, or ambient air) is associated with PCE spills or accidental release. PCE is toxic to humans at very low concentrations.

Does PCE degrade to TCE?

PCE, for example, though strictly non-biodegradable under aerobic conditions, can be microbially transformed to TCE, cis-dichloroethylene (cDCE), vinyl chloride (VC), and ethene in a highly reducing ground water environment.

Is PCE an Lnapl or Dnapl?

Mobility of PCE is described as moderate (Fetter 1988) with an average solubility in groundwater of 200 mg/L, and a soil-water partition coefficient (Koc) of 152. PCE is a dense non-aqueous phase liquid (DNAPL). A DNAPL is denser than and immiscible in water. In the presence of water it will form a separate phase.

What is the difference between TCE and PCE?

TCE and PCE are man-made chemicals and were used often in manufacturing. TCE is a nonflammable colorless liquid. PCE is a nonflammable liquid. It is used frequently in dry cleaning and to remove grease.

What is PCE waste?

PCE is a manufactured chemical used mostly as a cleaning agent. PCE is a colorless, nonflammable liquid with a faint, sweet odor. It is also a volatile organic compound, which means it can turn into a gas.

Does PCE evaporate?

PCE evaporates (changes from a liquid to a gas) easily into the air when it is used. It can also evaporate into the air if it is not properly stored or if it is spilled.

Is TCE a daughter product of PCE?

The primary daughter products include trichloroethylene (TCE), cis-1,2-dichloroethylene (cis-DCE), trans-1,2-dichloroethylene (trans-DCE), and vinyl chloride (VC). The daughter products can be as dangerous to human health and the environment as PCE (in some cases, more dangerous).

What are the degradation products of TCE?

TCE degradation products of three dichloroethene (DCE) isomers, vinyl chloride (VC) and ethene were present.

Are chlorinated solvents Dnapl?

Possibly the most common DNAPLs are chlorinated solvents such as trichloroethylene (TCE), tetrachloroethylene (PCE), and carbon tetrachloride (CCl4).

Is benzene a Lnapl?

A light non-aqueous phase liquid (LNAPL) is a groundwater contaminant that is not soluble in water and has lower density than water, in contrast to a DNAPL which has higher density than water. Examples of LNAPLs are benzene, toluene, xylene, and other hydrocarbons.

How do you get rid of PCE in groundwater?

Treatment of groundwater containing PCE includes traditional pump-and-treat technology (using air stripping or activated carbon filtration), in situchemical oxidation with peroxide or ozone, de-chlorination by Hydrogen- Releasing Compound (HRC) and emerging biodegradation techniques. An important part of PCE DNAPL remediation is source removal.

Do aquifer microorganisms dechlorinate PCE and TCE?

Subsequent investigation revealed that, under reducing conditions, aquifer microorganisms can reductively dechlorinate PCE and TCE to the less chlorinated daughter products, dichloroethene (DCE) and vinyl chloride (VC).

Are chloroethenes biodegradable in ground water?

The chloroethenes, tetrachloroethene (PCE) and trichloroethene (TCE), are among the most common contaminants detected in ground water systems. As recently as 1980, the consensus was that chloroethene compounds were not significantly biodegradable in ground-water.

Is complete dechlorination of ground water possible?

Although recent laboratory studies conducted with halorespiring microorganisms suggest that complete reduction to ethene is possible, in the majority of ground-water systems reductive dechlorination apparently stops at DCE or VC.