Enhanced copper removal from contaminated kaolinite soil by electrokinetic process using compost reactive filter media

Romina Ghobadi; Ali Altaee; John L Zhou; Peter McLean; Namuun Ganbat; Donghao Li

doi:10.1016/j.jhazmat.2020.123891

Enhanced copper removal from contaminated kaolinite soil by electrokinetic process using compost reactive filter media

J Hazard Mater. 2021 Jan 15:402:123891. doi: 10.1016/j.jhazmat.2020.123891. Epub 2020 Sep 6.

Authors

Romina Ghobadi¹, Ali Altaee², John L Zhou³, Peter McLean⁴, Namuun Ganbat¹, Donghao Li⁵

Affiliations

¹ Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia.
² Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia. Electronic address: ali.altaee@uts.edu.au.
³ Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia. Electronic address: junliang.zhou@uts.edu.au.
⁴ School of Electrical and Data Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia.
⁵ Department of Chemistry, MOE Key Laboratory of Biological Resources of Changbai Mountain & Functional Molecules, Yanbian University, Yanji, 133002, Jilin Province, PR China.

PMID: 33254824
DOI: 10.1016/j.jhazmat.2020.123891

Abstract

Electrokinetic (EK) remediation is a promising technology for soil decontamination, although basic pH in the soil close to cathode has constrained EK effectiveness due to heavy metal precipitation. This study aimed to enhance copper removal from kaolinite soil by integrating EK with compost (C) as recyclable reactive filter media (RFM) for the first time. Compost placed near the cathode served as an adsorbent to bind copper ions while buffering the advancement of the alkaline front in soil. The total copper removal rate increased from 1.03% in EK to 45.65% in EK-100%C under an electric potential of 10 V. Further experiments conducted by using biochar (BC) and compost/biochar (C + BC) mixture RFM at different ratios showed total Cu removal efficiency decreasing as EK-100%C > EK-(10%BC + 90%C) > EK-(20%BC + 80%C) > EK-(30%BC + 70%C) > EK. The application of a constant electric current of 20.00 mA further enhanced copper removal to 84.09% in EK-100%C although did not show significant enhancement in EK-(BC + C). The compost RFM was regenerated by acid extraction and then reused twice, achieving a total removal of 74.11%. The findings demonstrated compost as a promising and reusable RFM for the efficient removal of copper in contaminated soil.

Keywords: Copper; Electrokinetic; Heavy metals; Reactive filter media; Soil decontamination.

Publication types

Research Support, Non-U.S. Gov't