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International Journal of Environment and Sustainability, 2016, 5(1): 46-50 47
1.1 Stabilization/Solidifications (S/S) Tech- prevents soil contaminants from spreading into
nology the surrounding environment. There are many
advantages of the S/S technology as listed
Governmental agencies and individuals have below (Wiles, 1987):
adopted the S/S technology, and it has proven
to be reliable. The S/S technique has been - Good long-term stability, both physically and
effectively used for treating and reclaiming soils chemically
contaminated by petroleum oil utilizing various
chemical additives termed stabilizers, such as - Positive impact and comprehensive strength
Portland cement, lime, fly ash, etc. The treated
soil can be utilized in many ways such as - High resistance against biodegradation
landfilling and backfilling, road construction,
making brick blocks, etc. There are numerous - Relatively low water permeability
techniques for soil waste remediation that can
be used for treatment, but S/S appears to be - Non-toxicity of the chemical ingredients used
more effective and accurate. In addition, S/S for S/S
technology has been described by the U.S.
Environmental Protection Agency (EPA) as the Shah et al., 2002 reported that, by using cement,
greatest accessible technology for 57 RCRA lime, and fly ash to stabilize oil-contaminated
(Resource Conservation and Recovery Act) soils, the oil contamination of soil decreases the
listed hazardous wastes (Paria and Yuet, 2006). maximum dry density by 4%, cohesion by 66%,
The EPA considers S/S to be an established angle of internal friction by 23%, unconfined
treatment technology and has selected the compressive strength (UCS) by 35%, and
technology at 25% of the Superfund program increases the liquid limit by 11%.
remediation sites, as depicted in Figure 1, due to
its ability to treat different hazardous consti- The results of tests using S/S technology
tuents within the same media and in situ. indicate that the stabilization agents improve
Furthermore, the methods for studying the the geotechnical properties of the soil by way of
effectiveness of the S/S process are physical, cation exchange, agglomeration, and cementing.
chemical, and microstructural. The improvement in unconfined compressive
strength, cohesion, and angle of internal friction
1.2 Stabilizers Used in S/S Technology can be attributed to neo-formations, such as
calcium silicate hydrates (C-S-H) that coat and
Stabilizers used in S/S technology are either bind the soil particles (Shah et al., 2002).
inorganic or organic, and the organic stabilizers
should be safe for the environmental, offered The treatment processes by S/S technology are
locally, and economically worthwhile. Initially, designed to achieve one or more of the
lime and cement were conventionally used for following:
S/S treatment, but later on the utilization of
waste materials having cementing properties - Improve the handling and physical charac-
for S/S treatment has become a common teristics of the waste
practice. Tuncan et al. (2000) reported that by
using cement, fly ash, and lime to stabilize - Decrease the surface area of the waste mass,
petroleum-contaminated soils, the addition of leading a reduction in the mobility of conta-
5% cement, 10% fly ash, and 20% lime showed minants and blocking them
the better strength.
- Reduce the solubility of hazardous consti-
2. S/S Technology Advantages and Appli- tuents in the waste
cations
- Some of the applications of S/S technology for
In fact, the stabilization/solidification does not in-situ treatment of polluted soils and their ex-
remove the contaminants from the soil. It only situ examples are as follows:
- Remediation of lead and petroleum conta-
minated soils at a Boston Brownfield site using
cement-based S/S
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