3.2 The Distribution of Electrical Conductivity
Electrical Conductivity (EC) is a relevant parameter concerned about the
salt accumulation in soil specimen (Bessaim et al., 2019). The
distribution of EC across the soil column after the V-EK treatment is
illustrated in Fig.3. For the control column that without EK treatment
(voltage = 0 V), the soil in surface layer (> -15cm) has
the highest EC value at 1721 μS/cm due to the salt rises from the
bottom, and the EC values of salty soil under the surface were in the
range of 581-1127 μS/cm. With V-EK treatment, the lower values of EC
were observed in the soil within 50 cm below the surface with the
voltage at 10 V and 20 V, reached to a value of 67-230 μs/cm, which was
much lower than the minimum value (581 μs/cm) in control column.
Besides, the other lower values of EC were found between
EA and EB (electrodes located at the
-80cm and -60cm respectively) with range of 93-134 μs/cm, and this is
attributed to the transport and movement of ionic compounds toward the
electrode of opposite charges by EK processes under the applied
electrical filed (Jayasekera & Hall, 2007; Cho et al. 2010; Zhu et al.
2016). Thus, the higher EC values were appeared near EAand EB. And another reason for this was the generation
of ions by electrolytic around EA and
EB. It can see from the pH changes of around
EA and EB (Fig. S3). Additionally, EC
value around EA is higher than EB due to
the production of H+ at anode, which is very
conductive and migrate 1.8 times faster than OH-(Bessaim et al., 2019b). The conclusion is that ions were mitigated
effectively under V-EK treatment, especially at the voltage of 10V and
20V.