information about nZVI behavior, migration, and fate below the ground serves as a
tool for the evaluation of their remediation efficiency.
Nanoscale zero-valent iron is a progressive material for in situ remediation of
contaminated sites. Besides testing the reactivity of iron nanoparticles with a broad
range of diverse contaminants, e.g., Cr(VI), chlorinated ethenes, lindane, heavy
metals, it is equally important to find out how far the nanoparticles are able to
migrate to ensure contact with the contaminant in the subsurface. Migration of zerovalent iron in groundwater is a task that is investigated from different points of view.
The experimental equipment is usually arranged as a one-dimensional assignment
(laboratory column) in various setups with different ways of detecting migrating
substances (see Chap. 30)
The two- and three-dimensional experimental equipment (VEGAS research facility, University of Stuttgart), preferably with large-scale dimension, enables to
conduct a detailed study of the migration of nZVI particles in a homogeneous
artificial aquifer under conditions simulating real situations. The experimental
setup at VEGAS has a scale from 1 Â 0.12 Â 0.7 m to 8 Â 1 Â 3 m (L Â W Â H)
(Pešková et al. 2016) enabling the visualization of nZVI migration by injecting the
nanoparticles into the source zone of contamination (direct-push), as well as comparing the migration properties of different nZVI particles. Moreover, such a largescale 3D experiment allows a calculation of the spread efficiency of the particles in
the subsurface and, in particular, the quantification of the whole remedial action.
The basic steps in all studies focused on the evaluation of fate and migration of
nZVI during groundwater remediation include detailed field research and proper
design of the monitoring system. In order to explore hydrological and geological
profile of the remediated site, it is necessary to create a sufficient number of
monitoring wells of the appropriate depth and position. Another crucial step of
nZVI tracing is groundwater/soil/sediment sampling itself. A detailed sampling
plan has to be proposed in advance, considering the main targets and outputs of
nZVI tracing analysis (Laborda et al. 2016).
Distinguishing between injected nZVI particles (including their transformation
products) and naturally occurring iron-bearing colloids represents perhaps the most
complex problem in the whole process described (Černík 2010).
In the next paragraphs, we focus on technical solutions for reliable and practically
usable tracing of nZVI particles in the environment during/after the nanoremediation
action. Different methods and approaches are discussed and experience of their
on-site application is presented.
33.2 Sampling Procedure
In order to precisely track the injected nZVI particles at the remediated site, a
complex system of monitoring wells is needed. The specific number and position
of the wells depends on a particular (hydro)geological profile, groundwater flow
direction and velocity as well as general site situation. Nevertheless, special attention
should always be paid to designing and constructing the monitoring system.
634
P. Skácelová and J. Filip
tool for the evaluation of their remediation efficiency.
Nanoscale zero-valent iron is a progressive material for in situ remediation of
contaminated sites. Besides testing the reactivity of iron nanoparticles with a broad
range of diverse contaminants, e.g., Cr(VI), chlorinated ethenes, lindane, heavy
metals, it is equally important to find out how far the nanoparticles are able to
migrate to ensure contact with the contaminant in the subsurface. Migration of zerovalent iron in groundwater is a task that is investigated from different points of view.
The experimental equipment is usually arranged as a one-dimensional assignment
(laboratory column) in various setups with different ways of detecting migrating
substances (see Chap. 30)
The two- and three-dimensional experimental equipment (VEGAS research facility, University of Stuttgart), preferably with large-scale dimension, enables to
conduct a detailed study of the migration of nZVI particles in a homogeneous
artificial aquifer under conditions simulating real situations. The experimental
setup at VEGAS has a scale from 1 Â 0.12 Â 0.7 m to 8 Â 1 Â 3 m (L Â W Â H)
(Pešková et al. 2016) enabling the visualization of nZVI migration by injecting the
nanoparticles into the source zone of contamination (direct-push), as well as comparing the migration properties of different nZVI particles. Moreover, such a largescale 3D experiment allows a calculation of the spread efficiency of the particles in
the subsurface and, in particular, the quantification of the whole remedial action.
The basic steps in all studies focused on the evaluation of fate and migration of
nZVI during groundwater remediation include detailed field research and proper
design of the monitoring system. In order to explore hydrological and geological
profile of the remediated site, it is necessary to create a sufficient number of
monitoring wells of the appropriate depth and position. Another crucial step of
nZVI tracing is groundwater/soil/sediment sampling itself. A detailed sampling
plan has to be proposed in advance, considering the main targets and outputs of
nZVI tracing analysis (Laborda et al. 2016).
Distinguishing between injected nZVI particles (including their transformation
products) and naturally occurring iron-bearing colloids represents perhaps the most
complex problem in the whole process described (Černík 2010).
In the next paragraphs, we focus on technical solutions for reliable and practically
usable tracing of nZVI particles in the environment during/after the nanoremediation
action. Different methods and approaches are discussed and experience of their
on-site application is presented.
33.2 Sampling Procedure
In order to precisely track the injected nZVI particles at the remediated site, a
complex system of monitoring wells is needed. The specific number and position
of the wells depends on a particular (hydro)geological profile, groundwater flow
direction and velocity as well as general site situation. Nevertheless, special attention
should always be paid to designing and constructing the monitoring system.
634
P. Skácelová and J. Filip