| Title: |
Assessment of trace element stabilization in soil
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| Resource Type: |
document --> technical publication --> Phd thesis
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| Country: |
Sweden
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| Year: |
2005 |
| Availability: |
Author Kumpiene, Jurate.
Titel Assessment of trace element stabilization in soil / Jurate Kumpiene
Luleå, 2005
Fysisk beskr 28 pages. : ill.
Serie Doctoral thesis / Luleå University of Technology, ISSN:1402-1544 ; 2005:38
Institution Luleå Universitet of Technology. Institutionen för samhällsbyggnad.
Dissertation. Luleå : Luleå tekniska univ., 20
Länk http://epubl.luth.se/1402-1544/2005/38 ;
Class Soil remediation
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| Author 1/Producer: |
Kumpiene, Jurate
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| Author / Producer Type: |
University research group / research institute
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| Publisher: |
Luleå Univerity of Technology
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| Publisher City: |
Luleå, Sweden
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| ISBN: |
ISSN 1402-1544
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| Report / download web link (=direct link): |
http://epubl.luth.se/1402-1544/2005/38
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| Format (e.g. PDF): |
PDF
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| Size: (e.g. 20mb) |
9.4
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EUGRIS Keyword(s): |
Contaminated land-->Contaminants-->Heavy metals
Contaminated land-->Remediation options-->Ex situ treatment technologies
Contaminated land-->Remediation options-->In situ treatment technologies
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| Short description: |
The thesis deals with the remediation of trace element contaminated soil by the chemical stabilization technique. The objective is to complement the knowledge about possibilities of applying the stabilization either (1) as an alternate soil remediation method to excavation and landfilling or (2) for a pre-treatment of contaminated soil before landfilling. The work is based on two case studies of the stabilization of 1) Cr, Cu, As, and Zn contaminated soil using metallic iron and 2) Pb and Cu contaminated soil amended with coal fly ash and natural organic matter. The questions in focus were: How efficient the stabilization is in a multi-element contaminated soil? How to assess the soil stabilization efficiency? Is the technique sufficiently developed to be used in large scale applications? A literature review, laboratory and pilot scale field experiments were performed to answer the raised questions. A relevance of various methods for the stability evaluations, as well as environmental, regulatory and economic aspects managing the treated soil are discussed.
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| Long description: |
Stabilization is a soil remediation method used to reduce the mobile and bioavailable
contaminant fraction in soil by trace element-immobilizing amendments. It has recently
been considered as a possible alternative to conventional soil remediation techniques (e.g.
excavation and disposal at landfills), since the risk to human health and the environment
arises from the contaminant bioavailability and not from its total concentration in soil.
Three types of amendments were tested for their abilities to reduce contaminant mobility in
soil: zerovalet iron (Fe0) in the form of iron grit, coal fly ash (CFA) from wood and coal
combustion, and natural organic matter – peat (OM). The stabilization of the soils
contaminated with Pb and Cu (soil S) and wood impregnation chemical CCA (soil R), as
assessed by batch leaching tests and the pilot scale field (lysimeter) experiment,
significantly reduced the leaching of all analyzed elements. Treatment efficiency decreased
in the following order (%): Pb(>99)>Cu(98) in soil S and As(99)��Zn(99)>Cu(93)>Cr(57)
in soil R.
Critical factors controlling element mobility in the Fe0-treated soil R were identified by a
factorial design of experiment. Five factors were selected, namely pH, liquid-to-solid ratio
(L/S), redox potential (Eh), microbial activity (MA) and organic matter (OM) content.
Among these, pH was the most important factor controlling the mobility of Cr, Cu and Zn
in the treated soil. Low pH caused remobilization of these elements. L/S and MA were the
most influential for As stability. The mobility of As in the treated soil was low at low L/S
and the presence of MA but considerably increased at the opposite levels of these factors.
The results on As leaching obtained by the standard compliance batch leaching test may
not be reliable if the As-contaminated soil, even after stabilization with Fe, is disposed of at
an anaerobic landfill. Limited air access interferes with the stability of Fe oxides and
substantially increases the risk of As release.
The stabilization method of the CCA-contaminated soil with Fe needs further
improvements despite the future utilization of treated soil. Neither in situ application (due
to the high bioaccessibility and potential mobility of Cu along with access of percolating
water) nor disposal at traditional anaerobic landfills (due to remobilization of As) are yet a
safe option for handling Fe-treated soil. By contrast, the amendment of Cu and Pbcontaminated
soil with CFA-OM reduced the metal mobility, as estimated by different
physico-chemical methods, facilitated the soil revegetation with grass, and reduced the soil
toxicity to plants and bacteria, thereby showing that this can be a suitable method for in situ
soil remediation of Cu and Pb contaminated soil, even at high total concentrations of the
metals.
Further development of the stabilization technique may help to achieve the environmental
goal of a Non-Toxic Environment, since stabilization can reduce the risk that contaminants
pose to human health and the environment by modifying their mobility and availability in
soil.
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Submitted By:
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Mr Thomas Liljedahl WhoDoesWhat?
Last update: 13/10/2006
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