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CHEE 484- Bioremediation

Assignment 1: Remediation Technologies

Jenna Schellen

Excavation & Incineration

Challenges associated with effectively remediating contaminated sites within a reasonable time framehave led industry to solutions such as excavation and incineration. These short duration treatments,

resulting in the complete removal of contaminants from the site, have become a cost effective way to

remediate sites. However, increasing landfill costs may have contributed to a decrease in the application

of this method since 1993.

Excavation

Excavation or dig and haul involves removing contaminated soil from site and disposing of it in

landfills. This process consists of dust mitigation and soil excavation followed by site restoration and

groundwater monitoring. This method is applied to sites with small quantities of soil not characterized

as hazardous waste and those with difficult to treat contaminants.

Incineration

Incineration eliminates pollutants by burning the soil in a kiln at temperatures ranging from 650-1200C.

The ash is then fed into a cooling screw conveyor and sprayed with water to further reduce its

temperature before being transferred into dumpsters which are later removed and deposited off site. A

secondary combustion chamber (SCC) operating at a higher temperature further reduces any residual

contaminants in the gas. A quench chamber is used to cool gases leaving the SCC through water

evaporation. Optional scrubbers can be used to remove and acid gas that may have been produced

during combustion by neutralizing with sodium hydroxide.

Figure 1: Schematic of a mobile incinerator (Acharya, P., Pfrommer, C. (1998))

Harbottle, M.J et al(2008)

8/3/2019 JennaSchellenExcavationIncineration

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CHEE 484- Bioremediation

Assignment 1: Remediation Technologies

Jenna Schellen

Pros and Cons

Dig and Dump

Pros Cons

Applicable to wide range of contaminants

(often used with heavy metals)

No actual remediation occurring, just

relocation

Cost-effective Unsustainable: limited landfill space

Immediate results: site considered

remediated once excavated soil is removed

Applicable to sites with contaminated matter

in topsoil (small volumes)

Effectively removes all contamination

(high "efficiency")

Potentially create other negative effects

(groundwater contamination, soil structure

and habitat degradation)

Incineration

Pros Cons

Short treatment duration Efficiency dependent on soil characteristics

Removes range of organics and combustible

compounds (PCBs etc)Can be costly

Permanently destroys hazardous and organic

contaminants

Limited applicable area: excavation soil

deeper than topsoil impractical

Flexible application to wide range of

materials and soil types

Concern over air emissions and restrictions

put in place by regulatory bodies limit use

Resources

(1) Page, C.A., Diamond, M.L., Campbell, M. &McKenna, S.. (Aug 1998) Take a life-cycle view of site remediation.Chemical Engineering Progress. New York. Vol. 94, Iss. 8; pg. 63, 8 pgs

(2) Hockman, B. (1992)Journal of Hazardous Materials, 32, 129-136(3) Harbottle, M.J., Al-Tabbaa, A., Evans, C.W. (April 2008). Sustainability of land remediation. Part 1: overall analysis.

Geotechnical Engineering. Issue GE2 pg 75-92

(4) Perdek, J.M. (1997). Decision Analysis of Incineration Costs in Superfund Site Remediation. Environmental EngineeringScience. Vol 14, 1

(5) Valenti, M. (1994). Cleaning soil without incineration. Mechanical Engineering, Vol. 116, Issue 5(6) Acharya, P., Pfrommer, C.. (1998). Twenty years of site remediation via incineration in the United States.

Environmental Progress. Vol. 17, iss. 1, pg 31-37

(7) Leuser, R.M, Velazquez, L.A, Cohen, A. & Janssen, J. (1990). Remediation of PCB Soil Contamination by On-SiteIncineration.Journal of Hazardous Materials, 25 pg375-385

(8) Simon, J. (2007). Editors Perspective- Surverys Reveal Trends in Remedy Selection. Remediation, Winter pg 1-5