5.1 Introduction
Chlorinated ethenes are common contaminants, which have been used in a range of
industrial application (Paul and Smolders 2014). They represent one of the most
persistent organic pollutants due to their strong carbon-chlorine bond (Adetutu et al.
2015).
A basic treatment technology applied commonly on many sites is a pump-andtreat remediation system, which consists of pumping of polluted groundwater and its
ex situ treatment. Due to relatively high cost of ex situ treatment, there has been a
rapid development of in situ processes that do not create any residual waste unlike in
situ chemical reduction (ISCR) and oxidation (ISCO) or biodegradation (Stroo and
Ward 2010). The application of ISCR using nanoscale zero-valent iron particles for
contaminated groundwater remediation is nowadays one of the standard methods for
in situ treatment or stabilization of chlorinated hydrocarbons, selected inorganic
anions, heavy metals, and others. This method has been successfully applied to many
sites in the Czech Republic and worldwide.
The effectiveness of ISCR by nZVI depends on the geological and
hydrogeological conditions, which affect both the reactivity of nanoparticles with
contaminants and their spreading in the subsurface. Practically, it is very important
to choose a good material. This work is focused on comparison of three different
materials by their efficiency:
• NANOFER STAR, a commercially available product
• NZVI-C3, nanoparticles fabricated by Palacký University Olomouc
• NANOFER STAR modified by carboxymethyl cellulose to increase mobility of
nZVI
5.2 Materials and Methods
5.2.1 Site Description
The studied area is located in one of the largest chemical plants in the Czech
Republic with history of 140 years of chemical production. A long-term chemical
and metallurgical production and incautious manipulation with dangerous materials
led to chemical contamination of the site.
Field tests with nZVI were performed in one of the most contaminated areas of
the site. The aquifer is formed by Quaternary terrace that consists of fluvial gravels
and sands with various amounts of clayey material within the whole profile. The
terrace lies 4–14 m under the surface. The lower part of the terrace consists of gravel
and gravelly sand with basalt pebbles of the average size of 15 cm or quartz pebbles
of 10 cm (Kvapil et al. 2014).
Hydraulic conductivity of the aquifer varies between 6 Â 10
À5 and 2 Â 10
À4 m/s,
which corresponds to the intermediate and higher values of hydraulic conductivity.
88
V. Stejskal and N. Vacková
Chlorinated ethenes are common contaminants, which have been used in a range of
industrial application (Paul and Smolders 2014). They represent one of the most
persistent organic pollutants due to their strong carbon-chlorine bond (Adetutu et al.
2015).
A basic treatment technology applied commonly on many sites is a pump-andtreat remediation system, which consists of pumping of polluted groundwater and its
ex situ treatment. Due to relatively high cost of ex situ treatment, there has been a
rapid development of in situ processes that do not create any residual waste unlike in
situ chemical reduction (ISCR) and oxidation (ISCO) or biodegradation (Stroo and
Ward 2010). The application of ISCR using nanoscale zero-valent iron particles for
contaminated groundwater remediation is nowadays one of the standard methods for
in situ treatment or stabilization of chlorinated hydrocarbons, selected inorganic
anions, heavy metals, and others. This method has been successfully applied to many
sites in the Czech Republic and worldwide.
The effectiveness of ISCR by nZVI depends on the geological and
hydrogeological conditions, which affect both the reactivity of nanoparticles with
contaminants and their spreading in the subsurface. Practically, it is very important
to choose a good material. This work is focused on comparison of three different
materials by their efficiency:
• NANOFER STAR, a commercially available product
• NZVI-C3, nanoparticles fabricated by Palacký University Olomouc
• NANOFER STAR modified by carboxymethyl cellulose to increase mobility of
nZVI
5.2 Materials and Methods
5.2.1 Site Description
The studied area is located in one of the largest chemical plants in the Czech
Republic with history of 140 years of chemical production. A long-term chemical
and metallurgical production and incautious manipulation with dangerous materials
led to chemical contamination of the site.
Field tests with nZVI were performed in one of the most contaminated areas of
the site. The aquifer is formed by Quaternary terrace that consists of fluvial gravels
and sands with various amounts of clayey material within the whole profile. The
terrace lies 4–14 m under the surface. The lower part of the terrace consists of gravel
and gravelly sand with basalt pebbles of the average size of 15 cm or quartz pebbles
of 10 cm (Kvapil et al. 2014).
Hydraulic conductivity of the aquifer varies between 6 Â 10
À5 and 2 Â 10
À4 m/s,
which corresponds to the intermediate and higher values of hydraulic conductivity.
88
V. Stejskal and N. Vacková