title: Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type.
abstract: Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero valent iron particles in a two-compartment cell is tested and compared to a more conventional combination of electrokinetic remediation and nZVI in a three-compartment cell. In the new two-compartment cell, the soil is suspended and stirred simultaneously with the addition of zero valent iron nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two-compartment and the three-compartment cell, respectively. The highest removal with Soil 2 were 58% and 45%, in the two-compartment and the three-compartment cell, respectively, in the experiments without direct current. The pH of the soil suspension in the two-compartment treatment appears to be a determining factor for the PCB dechlorination, and this cell allowed a uniform distribution of the nanoparticles in the soil, while there was iron accumulation in the injection reservoir in the three-compartment cell.
authors.affiliation: CENSE - Center for Environmental and Sustainability Research, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; CERNAS - Research Center for Natural Resources, Environment and Society, Escola Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601 Coimbra, Portugal; Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK 2800 Kgs. Lyngby, Denmark. Electronic address: hrg@campus.fct.unl.pt.
authors.forename: Helena I
authors.initials: HI
authors.lastname: Gomes
authors.affiliation: CERNAS - Research Center for Natural Resources, Environment and Society, Escola Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601 Coimbra, Portugal.
authors.forename: Celia
authors.initials: C
authors.lastname: Dias-Ferreira
authors.affiliation: Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK 2800 Kgs. Lyngby, Denmark.
authors.forename: Lisbeth M
authors.initials: LM
authors.lastname: Ottosen
authors.affiliation: CENSE - Center for Environmental and Sustainability Research, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Alexandra B
authors.initials: AB
authors.lastname: Ribeiro
mesh_terms: D055664:Electrochemical Techniques; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007501:Iron / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls; D007501:Iron
keywords: Contaminated soil; Electroremediation; Polychlorinated biphenyls PCB; nZVI