Significant removal of As was observed at the 1D electrode configuration. The area
covered by electrodes equaled 8.0 m
2 ; the accumulated energy consumption of the
2D system was about three times higher than that of the 1D system. However, the
operation time of the 2D configuration was longer than for the 1D configuration, and
the energy consumption of 2D was only 20% of 1D. There were 15 and 5 electrodes
in the 1D and 2D configurations, respectively, showing that the 2D system was more
efficient than the 1D electrode configuration for remediation of the contaminated soil
with cost-effectiveness in terms of electrode and energy consumption. Even though
the operation time of the 2D was longer as compared to the 1D, they concluded that
the 2D electrode configuration was a more economical and viable process than the
1D electrode configuration. Other investigators evaluated the 2D electrode configuration such as a rectangular or hexagonal arrangement for removal of heavy metals,
salinity, etc. Kim et al. (2014a, b, c) conducted an experiment to enhance As removal
in paddy soil for field application and evaluated four different configurations of the
2D electrode configuration. They used two different cell configurations: hexagonal
type (H1, H2) and square type (S1, S2). The anode was fixed in the midpoint of the
configuration, where cathodes were surrounded by the anode. In their findings, the
2D electrode configuration increased the effective area of EK remediation, and the
hexagonal configuration gave 78.9% efficiency, which was higher than the square
type configuration (50%). Further research is continuing to improve the 2D electrode
cell configuration.
2.3 Electrokinetic Removal of Soluble Salts
Soil salinity is a crucial environmental problem for plant cultivation worldwide. The
United Nations Environment Program (UNEP) estimated during 2005 that nearly
20% and 50% of agricultural land and cropland, respectively, in the world is salt
stressed (Saichek and Reddy 2005). Annamalai et al. (2014a, b) identified a high
saline- and dye-contaminated area in Tirupur, on the Noyyal River bank, for EK
treatment in polluted soil. They reported that the electrical conductivity of the soil
was about 16.13 dS/m, which is above the limiting level of agricultural norms. The
high levels of sodium, chloride, sulfate, nitrate, and potassium directly affect the
growth of plants. Under-drainage is a common method for reclaiming saline soils,
but the efficiency may be poor. Several methods were used to reduce the soil salinity:
chemical remediation, mechanical remediation, and phytoremediation. These
methods however are not economically feasible for practical applications. The EK
process for removal of soluble salts from saline soil is a more feasible method for
removal of salinity, and significant results were achieved in laboratory and field
applications. Salinity removal from various soil types of soil is presented in
Table 8.2, which covers all the relevant literature for future study.
8 Electro-bioremediation: An Advanced Remediation Technology for the. . .
191
covered by electrodes equaled 8.0 m
2 ; the accumulated energy consumption of the
2D system was about three times higher than that of the 1D system. However, the
operation time of the 2D configuration was longer than for the 1D configuration, and
the energy consumption of 2D was only 20% of 1D. There were 15 and 5 electrodes
in the 1D and 2D configurations, respectively, showing that the 2D system was more
efficient than the 1D electrode configuration for remediation of the contaminated soil
with cost-effectiveness in terms of electrode and energy consumption. Even though
the operation time of the 2D was longer as compared to the 1D, they concluded that
the 2D electrode configuration was a more economical and viable process than the
1D electrode configuration. Other investigators evaluated the 2D electrode configuration such as a rectangular or hexagonal arrangement for removal of heavy metals,
salinity, etc. Kim et al. (2014a, b, c) conducted an experiment to enhance As removal
in paddy soil for field application and evaluated four different configurations of the
2D electrode configuration. They used two different cell configurations: hexagonal
type (H1, H2) and square type (S1, S2). The anode was fixed in the midpoint of the
configuration, where cathodes were surrounded by the anode. In their findings, the
2D electrode configuration increased the effective area of EK remediation, and the
hexagonal configuration gave 78.9% efficiency, which was higher than the square
type configuration (50%). Further research is continuing to improve the 2D electrode
cell configuration.
2.3 Electrokinetic Removal of Soluble Salts
Soil salinity is a crucial environmental problem for plant cultivation worldwide. The
United Nations Environment Program (UNEP) estimated during 2005 that nearly
20% and 50% of agricultural land and cropland, respectively, in the world is salt
stressed (Saichek and Reddy 2005). Annamalai et al. (2014a, b) identified a high
saline- and dye-contaminated area in Tirupur, on the Noyyal River bank, for EK
treatment in polluted soil. They reported that the electrical conductivity of the soil
was about 16.13 dS/m, which is above the limiting level of agricultural norms. The
high levels of sodium, chloride, sulfate, nitrate, and potassium directly affect the
growth of plants. Under-drainage is a common method for reclaiming saline soils,
but the efficiency may be poor. Several methods were used to reduce the soil salinity:
chemical remediation, mechanical remediation, and phytoremediation. These
methods however are not economically feasible for practical applications. The EK
process for removal of soluble salts from saline soil is a more feasible method for
removal of salinity, and significant results were achieved in laboratory and field
applications. Salinity removal from various soil types of soil is presented in
Table 8.2, which covers all the relevant literature for future study.
8 Electro-bioremediation: An Advanced Remediation Technology for the. . .
191