Electrokinetic approach to assess the behaviour of a contaminated marine sediment

Garcia-Blas, Nieves; Jiménez-Relinque, Eva; Nevshupa, Roman; Castellote, Marta

doi:10.1007/s11368-020-02615-1

Cited by 7 publications

(5 citation statements)

References 43 publications

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“…Figure 2b demonstrates, as previously observed (Tang et al 2018;Garcia-Blas et al 2020a), a peak of current intensity that occurs in the first hours; afterwards, the intensity decreases exponentially, remaining relatively low (a few mA) and almost constant until the end in some of the tests (e.g. tests 1, 5, and 15).…”

Section: Electrical Properties Ph and Electroosmotic Flowsupporting

confidence: 84%

“…Arsenic and small amounts of Cu and Zn were found in the catholyte. Speciation of these metals during the electrokinetic tests is described in a previous publication by our group (Garcia-Blas et al 2020a). The maximum removal for each metal in function of the charge density passed (Ccm −2 ) in the anolyte, catholyte, and total at the end of the trial is shown in Fig.…”

Section: Removal Of Metalsmentioning

confidence: 98%

“…Fifteen electrokinetic remediation tests were performed using a U-shaped homemade electroosmotic cell device (ECD) described in detail in Garcia-Blas et al (2020a). The electrolytes were placed in two 55 cm 3 cylindrical chambers.…”

Section: Electrokinetic Remediation Testsmentioning

confidence: 99%

“…The surfactant tests lasted 65-72 h because it has previously been demonstrated that the highest removal takes place during the first hours (Garcia-Blas et al 2020a). The experimental parameters of the tests are detailed in Table 1.…”

Section: Electrokinetic Remediation Testsmentioning

confidence: 99%

“…Concerning removal of metals, most of the treatments incorporate the use of acidic solutions, chelates, or mixed solutions to solubilize them (Reddy and Chinthamreddy 2004;Meers et al 2005;Nystroem et al 2006;Peng et al 2009;Castellote and Botija 2011;Rozas and Castellote 2012;Pedersen et al 2015;Song et al 2016;Yuan et al 2016;Garcia-Blas et al 2020a;Ayyanar and Thatikonda 2021). Other treatments used redox agents (Chuan et al 1996;Reddy and Chinthamreddy 1999;Nystroem et al 2006;Cang et al 2013;Pazos et al 2013).…”

Section: Introductionmentioning

confidence: 99%

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Surfactants in electrokinetic remediation of sediments to enhance the removal of metals

2022

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Purpose The study focuses on the use of surfactants as enhancing solutions in electrokinetic remediation trials on sediments, with the hypothesis that they will allow heavy metals to desorb from organic matter, and thus favour their removal to the solution. Materials and methods A total of 15 remediation trials were conducted. As enhancing solutions, four different non-ionic commercial surfactants were used, either alone or in combination with citric acid (CA) or ethylenediaminetetraacetic acid (EDTA) in both compartments. A comparison with distilled water was also performed. 30–40 VDC was applied between activated titanium electrodes. The pH, electroosmotic flow (EOF), mineralogy of the samples (before and after the electrokinetic tests), and the percentage of removal of Cr, Ni, Cu, Zn, As, Cd, Pb, and Hg were determined. Results and discussion Every test showed an increase in current intensity during the first hours, and in certain cases, additional intensity peaks were found during the trial, which were mostly attributed to the establishment of EOF episodes. Depending on the case, EOF was transferred to the anolyte or the catholyte. Reversal of EOF occurred in one case, but was not detected in the others. Cr was primarily removed when CA was used. In the catholite, Ni, Cu, Zn, and Pb were extracted preferentially with EDTA. Surfactant B was more effective at removing Zn and As. Only a few treatments removed Cd with CA and surfactant C extracting the most. Hg was detected in the electrolytes of some experiments, being extracted with surfactant A in the catholyte in all cases, and with surfactant B and surfactant C with EDTA. Cr, Ni, Cu, Zn, Cd, and Pb were preferentially collected in the anolyte. Cu and Zn were found in trace levels in the catholyte. Conclusions Surfactants have been shown to help with metal solubilisation to different degrees depending on the metal. Each metal has a unique optimal species combination in the enhancing electrolyte. The direction of the EOF is determined by the chemical conditions of the system as a whole, not by the type of surfactant. Surfactants in combination with CA and EDTA improve desorption in general, which has been attributed to an increase in charge density passed during the tests rather than a symbiotic enhancement between both types of enhancing solutions.

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Section: Electrical Properties Ph and Electroosmotic Flowsupporting

confidence: 84%

Section: Removal Of Metalsmentioning

confidence: 98%

Section: Electrokinetic Remediation Testsmentioning

confidence: 99%

Section: Electrokinetic Remediation Testsmentioning

confidence: 99%