Environmental Engineering Reference
In-Depth Information
17.5 Special Techniques
17.5.1 Electrokinetic Enhanced Phytoremediation
Electro-kinetic remediation is an environmental restoration technique, which
involves energy application of a low DC current or a low potential gradient, in the
order of mA/cm
2
, to the two electrodes that are inserted into the sediments and
encompass the contaminated zone. The application of the electric potential causes
the ions to move to their respective electrodes designated as cathode and anode for
subsequent removal out of the contaminated soil. It is especially designed for the
in situ remediation of the contaminated soils (Cameselle et al.
2013
). The electro-
kinetic technology has been researched for over last two decades for the decon-
tamination of soil. It helps in removal of heavy metals, recalcitrant, and hydro-
phobic organic contaminants.
Cameselle et al. (
2013
) reported the development of new coupled technology of
electro-kinetic enhanced phytoremediation. This technology may lead to more
effective and efficient remedial strategy as compared to the sequential use of these
individual technologies (Fig.
17.5
).
Basically, the coupled phytoremediation-electrokinetic technology consists of
the application of a low intensity electric field to the contaminated soil in the
vicinity of growing plants. The electric field may enhance the removal of the
contaminants by increasing the bioavailability of the contaminants by desorption
and transport of contaminants, even over short distances (Cameselle et al.
2013
).
Variables that affect the coupled technology are: the use of AC or DC current,
voltage level and mode of voltage application (continuous or periodic), soil pH
evolution, and the addition of facilitating agents to enhance the mobility and
bioavailability of the contaminants.
In the coupled phytoremediation-EK technology, the removal or degradation of
the contaminants is performed by the plants; where as the electric field enhances
the plant activity by increasing the bioavailability of the contaminants. Since the
Fig. 17.5 Schematic
principle of electro-kinetic
soil remediation
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