Performance of electrokinetic remediation system for mercury contaminated marine sediment: Roles of electrode spacing and electrode configuration

• Published in: Marine pollution bulletin Vol. 194; no. Pt B; p. 115256
• Main Authors: Bunditboondee, Chotikoon, Lohwacharin, Jenyuk, Khan, Eakalak, Laohhasurayotin, Kritapas
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2023
• Subjects: Electrode configuration; Electrode spacing; Electrokinetic remediation (EK); Marine sediment; Mercury fraction; Electrokinetic remediation (EK); Electrode configuration; Electrode spacing; Marine sediment; Mercury fraction
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2023.115256

Understanding mercury (Hg) species existing after electrokinetic remediation (EK) for marine-sediment remediation is limited. Herein, the Hg fraction removal of EK from contaminated marine sediment was investigated appertaining to bipolar electrode settings along with the effects of electrode spacing and configuration considered. Based on the selective sequential Hg extractions (Hg SSE), much of the Hg in the sediment originated from F5 (i.e., HgS) and F4 (i.e., HgO). The F5 fraction removed by EK was about 30 %, while the F4 fraction had a slight increase of about 34 %. When it comes to electrode configuration, a hexagonal pattern has a higher Hg removal performance than that of a rectangular shape. The addition of anodes increases the remediation surface area, thus allowing superior Hg removal. This study indicates that the electrode spacing significantly affects the mercury removal and the remediation time. Determining suitable spacing enhances the electrical potentials in the migration flux. [Display omitted] •In selective sequential Hg extraction, Hg was contributed by F5 (HgS, HgSe) and F4 (HgO) fractions.•F5 fraction was removed by 30 %, while total Hg removal was 34 % by electrochemical process.•The highest percentage of Hg removal was achieved with an electrode spacing of 50 cm.•Hexagonal configuration yields higher Hg removals at cathode and anode than rectangular setting.