Surfactant combined with PASP enhance electrokinetic remediation removal heavy metal and hydrocarbon from contaminated soil

ABSTRACT

In this work, a new electrokinetic remediation technology was used to remove heavy metal and hydrocarbon from contaminated soil. The surfactant combined with PASP (Polyaspartic acid) was used to enhance heavy metal and hydrocarbon removing from contaminated soil. Electric current, soil pH, electroosmotic flow, water content variation, heavy metal removal efficiency and residual content distribution, heavy metal speciation, removal of TPH (total petroleum hydrocarbons), group composition of oil, mechanism of enhance electrokinetic remediation were investigated during the electrokinetic remediation process. Results indicated that Rhamnolipid, PASP, Tween 80 and SDS (sodium dodecyl sulphate) can reduce the heavy metal precipitation during the electrokinetic remediation process. Also, it can promote EOF (electroosmotic flow) and electrolyte evaporation during the EK remediation. The rhamnolipid (3.0 g.L⁻¹) combined with PASP (3.0 g.L⁻¹) can significantly improve Cu, Cr, Ni, Pb and hydrocarbon mobility and solubility during the EK remediations. Cu, Cr, Ni and Pb obtained the dominant removal efficiencies, which were 66.0 ± 3.45%, 61.2 ± 4.35%, 67.1 ± 3.21%, 61.8 ± 4.22%, respectively. Also, the TPH has attained a dominant removal efficiency of 80.2 ± 4.36% after the enhanced electrokinetic remediation. This research provides a novel in-situ remediation approach for reducing heavy metals and hydrocarbon from contaminated soil in an environmentally friendly way.

KEYWORDS:

• Contaminated soil
• heavy metals
• hydrocarbon
• electrokinetic remediation
• surfactant

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03067319.2022.2135999

Additional information

Funding

This research was financially supported by the Open Project of State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil and Water Pollution [No. GHBK-2020-002], Sichuan Science and Technology Program [No. 2021YJ0342], the Key Research and Development Project of Luzhou Science and Technology Planning Programs [No. 2020-SYF-20], Talent Introduction Funds of the Sichuan University of Science introduce hydrogen ion Engineering [No. 2020RC23], Luzhou Laojiao Limited Company Fund [No. 2022NB11] and National College Student’s innovation and entrepreneurship training program [No. 202110622016].