Nanoscale zero-valent iron-assisted soil washing for the removal of potentially toxic elements

The present study focuses on soil washing enhancement via soil pretreatment with nanoscale zero-valent iron (nZVI) for the remediation of potentially toxic elements. To this end, soil polluted with As, Cu, Hg, Pb and Sb was partitioned into various grain sizes (500?2000, 125?500 and <125??m). The...

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Detalhes bibliográficos
Autores: Boente López, Carlos, Sierra Fernández, Carlos, Martínez Blanco, David, Menéndez Aguado, Juan María, Rodríguez Gallego, José Luis
Tipo de documento: artigo
Data de publicação:2018
País:España
Recursos:Universidad de Cantabria (UC)
Repositório:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglês
OAI Identifier:oai:repositorio.unican.es:10902/13708
Acesso em linha:http://hdl.handle.net/10902/13708
Access Level:Acceso aberto
Palavra-chave:Soil remediation
Nanoscale zero-valent iron
Soil washing
PTEs
Descrição
Resumo:The present study focuses on soil washing enhancement via soil pretreatment with nanoscale zero-valent iron (nZVI) for the remediation of potentially toxic elements. To this end, soil polluted with As, Cu, Hg, Pb and Sb was partitioned into various grain sizes (500?2000, 125?500 and <125??m). The fractions were pretreated with nZVI and subsequently subjected, according to grain size, to Wet-High Intensity Magnetic Separation (WHIMS) or hydrocycloning. The results were compared with those obtained in the absence of nanoparticles. An exhaustive characterization of the magnetic signal of the nanoparticles was done. This provided valuable information regarding potentially toxic elements (PTEs) fate, and allowed a metallurgical accounting correction considering the dilution effects caused by nanoparticle addition. As a result, remarkable recovery yields were obtained for Cu, Pb and Sb, which concentrated with the nZVI in the magnetically separated fraction (WHIMS tests) and underflow (hydrocyclone tests). In contrast, Hg, concentrated in the non-magnetic fraction and overflow respectively, while the behavior of As was unaltered by the nZVI pretreatment. All things considered, the addition of nZVI enhanced the efficiency of soil washing, particularly for larger fractions (125?2000??m). The proposed methodology lays the foundations for nanoparticle utilization in soil washing operations.