<p>Approaching anode is one of the enhancement techniques in electrokinetic soil remediation. This technique is reported to give promising migration for heavy metals under shorter treatment time and at lower cost in comparison to normal fixed anode system. In the present study, the effectiveness of fixed anode and approaching anode techniques in electrokinetic soil remediation for lead migration under different types of wetting agents (0.01M NaNO3 and 0.1M citric acid) was investigated. The study showed that the use of citric acid enhanced lead migration in comparison to NaNO3. For NaNO3 tests, lead was found to accumulate in the middle of soil section due to high soil pH, which favoured lead adsorption and precipitation. Approaching anode reduced this effect by compressed high soil pH region and enhanced lead migration at cathode region. The approaching anode only showed technical advantages when NaNO3 was used whereas the enhancement in citric acid test was insignificant. Nevertheless, this technique reduced electricity usage by 18-20% for both wetting agents.</p
