Citric Acid-Enhanced Electroremediation of Toxic Metals from Dredged Sediments: Effect of Open/Closed Orifice Condition, Electric Potential and Surfactant

Abstract : Citric acid (CA), a widely used eco-friendly electrolyte, can be employed as an agent for enhancing toxic metal (TM) removal from contaminated dredged sediment using electrokinetic (EK) technology. In this study, dredged harbor sediments co-contaminated by TMs were subjected to enhanced EK treatment using a mixture of chelating agent (CA) and surfactant as an additive in the processing fluids. Several control conditions that may influence the efficiency of TM removal were tested, including open/closed sediment chamber orifices, electric potential gradients (0.5, 1.0, and 1.5 V cm-1), and electrolyte surfactant. Tween 20 (4 mmol L-1) was used as a surfactant within the electrolyte to investigate the extent of TM removal in sediment with high organic matter content. The results showed that an open orifice led to a greater electro-osmotic flow (EOF) with moderate TM removal. In contrast, a closed orifice with a nonionic surfactant electrolyte allowed the highest removal of TMs from the matrix. Moreover, increasing the electric potential gradient led to a higher EOF under the open orifice condition, but no significant increase in TM removal was observed owing to a higher accumulation of TMs in the middle of the matrix, caused by the opposite direction of EOF and electro-migration of metal-citrate complexes.
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https://hal-normandie-univ.archives-ouvertes.fr/hal-01712641
Contributeur : Valérie Casado-Malaizé <>
Soumis le : lundi 19 février 2018 - 16:43:03
Dernière modification le : vendredi 5 avril 2019 - 20:08:46

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Yue Song, Ahmed Benamar, S. Mezazigh, Wang Huaqing. Citric Acid-Enhanced Electroremediation of Toxic Metals from Dredged Sediments: Effect of Open/Closed Orifice Condition, Electric Potential and Surfactant. Pedosphere, Elsevier, 2018, 28 (1), pp.35-43. ⟨10.1016/S1002-0160(17)60xxx-x⟩. ⟨hal-01712641⟩

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