Biotechnological Aspects of Soil Decontamination - Biotechnologies and Biomimetics for Civil Engineering - page 369

Biological, physical, chemical, and other technologies can be used in con-
junction with one another to reduce the contamination to a safe and acceptable
level (RAAG 2000). Physical methods employs soil washing, encapsulation, and
solidification; precipitation and ion exchange are chemical treatments, and for the
biological treatment plants are used. Even though many technologies are available
for the decontamination of polluted sites, the selection depends on contaminant
and site-by-site basis, regulatory requirements, costs, and time constraints. Since
most remediation techniques are site-specific, the selection of appropriate tech-
nology is often a difficult, but extremely important step in the successful reme-
diation of a contaminated site. Therefore, the successful decontamination of a
contaminated site depends on proper selection of the methodology, its design, and
adjustment of the remediation technology's operations based on properties of the
contaminants and soils, and on the performance of the whole system (USEPA
1998 ; Khan et al. 2004 and Pazos et al. 2010 ).
This chapter provides the developing biotechnological aspects of soil decon-
tamination, and also reviews various other physical, chemical, electro-remediation
or electro-reclamation techniques. It also outlines the types of waste and media in
which the technology could be successfully applied so that wide-scale imple-
mentation and commercialization of the technique may be recommended on a
global basis.
17.2 Physical Techniques
Decontamination of soil relies on an understanding of the physical behavior of the
pollutants in the site specific environment. Physical remediation methods are most
effective in coarser textured soils, although fracturing of finer textured soils may
extend their applicability, and for pollutants that are more soluble or volatile. This
treatment can enhance the effectiveness of biological degradation of contaminates
or indirectly cause their destruction (Scullion 2006 ).
17.2.1 Off-Site Management
The most common traditional remediation technique is off-site management. The
contaminated soil is taken for burial at land fill sites. This method of remediation
merely shifts the contamination problem else where. Additionally, there are haz-
ards associated with the transport of contaminated soil and migration of contam-
inant from landfill into adjacent environment (Williams 1988 ).