Remediation of soil and water contaminated by heavy metals and hydrocarbons using silica encapsulation
Date
2008-10-27T07:34:26Z
Authors
Mbhele, Phelelani Phetheni
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Abstract
Heavy metals and hydrocarbons are persistent pollutants in the environment. Problems
associated with the cleanup of sites contaminated by metals and hydrocarbons have
demonstrated the need to develop remediation technologies that are feasible, quick, and
effective in a wide range of physical settings. Experiments were conducted to investigate
the efficiency of silica encapsulation and the factors that influence its performance.
Analysis was done by ICP-OES and GC-FID for metals and hydrocarbons respectively.
This technology was tested using sodium silicate and ChemcapTM.
Soils and water contaminated with hydrocarbons and heavy metals were successfully
remediated by silica encapsulation. The silica coating was stable under both acidic and
alkaline conditions. A new product that is based on sodium silicate formulation was
developed and was more effective at encapsulating hydrocarbons and heavy metals.
Laboratory tests indicated that it is more effective in an acidic medium and it continues to
strengthen with time. Metal encapsulation was affected by the sizes of metal ions and the
presence of hydrocarbons.
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Keywords
soil and water, silica encapsulation, heavy metals, hydrocarbons