The Application of Solar Cells in the Electrokinetic Remediation of Metal Contaminated Sediments

Abstract

In this study, solar cells were used to generate an electric field for the electrokinetic remediation of metal contaminated sediment (Nickel, Cadmium, Zinc). For determination of metals mobility, bioavailability and potential toxicity, sequential extraction procedure, simultaneously extracted metals (SEM) and acid-volatile sulphide ratios (AVS) were performed before, during and after treatment.After 21 days of treatment, 63% Ni, 82% Cd and 58% Zn was removed from the anode region. The application of the electric field changed the chemical composition of the sediments. The risk assessment analysis based on pseudo total metals content, the risk assessment code and the relationship between SEM and AVS, indicates that a simple singular approach for risk assessment analysis and evaluation of the quality of sediments is not enough.

Copper removal from sediment by electrokinetic treatment with electrodes in a hexagonal configuration

“…Similar conclusions were drawn by Krčmar et al., [ 19 ] Popov et al., [ 61 ] and Varga et al. [ 17 ] The efficiencies obtained after all the treatments indicate a significant reduction of Cu content in the sediment at locations 1, 2, 3, 4, 6, 7, 8, 9, respectively; according to the Serbian regulations, [ 62 ] these sites can be regarded as slightly polluted because they belong to class 2, while the sediment at sites 5 and 10 is still considered polluted (class 3). And considering that there is no significant difference in the achieved efficiencies, for real field application, the treatment e3, in which solar panels are applied, is recommended.…”

“…This confirms that even slight changes in pH by 1–2 pH units significantly affect the solubility of the metals present. [ 17 ] In Table 2, we can see that the pH value at locations 1, 2, 3, 6, 7, 8 after the end of the treatment was reduced by ~1.5 pH unit. Therefore, this, although at first glance a minor decrease in pH value, indicates that the total number of negative (hydroxyl) sites, clay minerals and OM decreases, and therefore the availability of metals increases, [ 58 ] in the case of Cu.…”

“…[ 16 ] for removing As from soil, by Varga et al. [ 17 ] for removing Ni, Cd and Zn from sediment, by Zhou et al. [ 18 ] for removing Cr from soil, by Krčmar et al.…”

“…[ 24 ] A detailed explanation of Serbian regulations is presented by Dubovina et al., [ 25 ] Kerkez et al., [ 26 ] Krčmar et al., [ 19 ] and Varga et al. [ 17 ] In our previous research [ 19 ] 2D EK treatment proved to be very successful for Ni removal. Moreover, in the study referred to above, we applied a model which showed satisfactory agreement with the experimental results.…”

“…[11] The success of applying solar panels in EK treatments for metal removal is evidenced by numerous literature data. [13] In particular, satisfactory results were achieved by Yuan et al [14] for removing Cd from soil, by Hassan et al [15] for removing Cu from soil, by Jeon et al [16] for removing As from soil, by Varga et al [17] for removing Ni, Cd and Zn from sediment, by Zhou et al [18] for removing Cr from soil, by Krčmar et al [19] for removing Ni from sediment, and by Hussein and Alatabe [20] for removing Pb from soil.…”