SOIL, SEDIMENT AND SLUDGE: EX-SITU CHEMICAL/PHYSICAL TREATMENT
Dehalogenation
Dehalogenation Process
Process
Note:
Uses
Limitations/Disadvantages:
Full-scale operation is estimated to be in a range of $220 to $550 per metric ton.
For further information:
http://www.frtr.gov/matrix2/section4/4-17.html#top
- Contaminated soil is screened, processed with a crusher and pug mill, and mixed with reagents.
- The mixture is heated to above 330 °C (644°F) in a reactor.
- Typically the halogen molecules are replaced, causing decomposition & partial volatilisation of the contaminants.
- The volatilised contaminants are captured, condensed, and treated separately.
Note:
- Normally a short- to medium-term process
- The contaminant is ONLY partially decomposed, NOT transferred to another medium nor fully treated.
- Treatment of the wastewater generated by the process may include chemical oxidation, biodegradation, carbon adsorption, or precipitation.
Uses
- Used to treat halogenated organics, halogenated SVOCs and pesticides. .
- Has also been used for soils and sediments contaminated with chlorinated organic compounds, especially PCBs, dioxins, and furans.
Limitations/Disadvantages:
- High clay and high moisture content will increase treatment costs.
- Generally not cost-effective for large waste volumes/high concentrations (require large volumes of reagent)
- May be difficult capture and treatment of residuals.
Full-scale operation is estimated to be in a range of $220 to $550 per metric ton.
For further information:
http://www.frtr.gov/matrix2/section4/4-17.html#top