In this study, Pb-contaminated soil in the e-waste dismantle site was remediated by activated carbon fiber (ACF) enhanced electrokinetic remediation. Experiments were conducted using Fe(NO3)3 as catholyte and citric acid-sodium citrate as anolyte with different conditions: pH value of anolyte, voltage and the electrode gap. At the same time, we set up a group of contrast test without ACF to investigate the adsorption performance of ACF for Pb. Results showed that the highest removal rate of Pb after the remediation was 80.53% at 4 cm from the anode when the electrode gap was 31 cm, pH value was 3 and the voltage was 28 V, and the total removal rate increased significantly with the decrease of the pH value of anolyte and the increase of voltage. Characterization of ACF after reaction showed that ACF effectively adsorbed heavy metal Pb, and the adsorption amount was 1.42 mg/g. Sequential extraction analysis revealed that Pb mainly existed in the forms of organic matter bound and residual in the soil after remediation. These forms are relatively stable and low toxicity, indicating that the remediation has significantly reduced the harm of Pb to the environment.
Keywords: ACF; E-waste dismantle site; Fe(NO3)3; Pb removal; electrokinetic remediation.