Pasciucco Erika, Pasciucco Francesco, Castagnoli Alessio, Iannelli Renato, Pecorini Isabella
Department of Energy, Systems Territory and Construction Engineering, Via C.F. Gabba 22, Tuscany, University of Pisa, Pisa, 56122, Italy.
Heliyon. 2024 Mar 13;10(6):e27616. doi: 10.1016/j.heliyon.2024.e27616. eCollection 2024 Mar 30.
Among the several treatment options, electrokinetic (EK) remediation is recognized as an effective technique for the removal of heavy metals from low-permeability porous matrices. However, most of the EK decontamination research reported was performed on linear configuration systems at a laboratory scale. In this study, a series of experiments were performed on a pilot-scale system where the electrodes were arranged in a hexagonal configuration, to assess the improvement of the EK process in the removal of inorganic contaminants from sediments dredged in the harbor of Piombino, Italy. HNO was used as acid conditioning and both pH effect and treatment duration time were investigated. Sediment characterization and metal fractionation were also presented, in order to understand how the bioavailability of metals affects the process efficiency. The increase in pH due to the buffering capacity of the sediment in the sections close to the cathode favored the precipitation and accumulation of metals. However, the results highlighted that longer treatment times, combined with an efficient pH reduction, can improve treatment performance, resulting in high removal efficiencies for all the target metals considered (a percentage removal greater than 50% was reached for Cd, Ni, Pb, Cu and Zn). Compared to different EK configuration systems, the hexagonal configuration arrangement applied in our study provides better results for the remediation of dredged marine sediment.
在几种处理方法中，电动修复（EK）被认为是一种从低渗透性多孔介质中去除重金属的有效技术。然而，大多数已报道的电动去污研究是在实验室规模的线性配置系统上进行的。在本研究中，在中试规模系统上进行了一系列实验，该系统中电极呈六边形配置，以评估电动过程在去除意大利皮翁比诺港疏浚沉积物中无机污染物方面的改进。使用硝酸进行酸调节，并研究了pH值影响和处理持续时间。还进行了沉积物表征和金属分级，以了解金属的生物有效性如何影响处理效率。靠近阴极部分的沉积物缓冲能力导致的pH值升高有利于金属的沉淀和积累。然而，结果表明，更长的处理时间与有效的pH值降低相结合，可以提高处理性能，使所有考虑的目标金属都具有高去除效率（镉、镍、铅、铜和锌的去除率达到50%以上）。与不同的电动配置系统相比，我们研究中应用的六边形配置排列在疏浚海洋沉积物修复方面提供了更好的结果。
