Electrolysis with diamond anodes of the effluents of a combined soil washing – ZVI dechlorination process

In this work, a new soil washing process in which Soil-Liquid extraction technology is enhanced by adding iron particles (zero valent iron nanoparticles or granules) was investigated to remove clopyralid from spiked soils. This novel approach can be efficiently used to extract chlorinated hydrocarbo...

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Bibliographic Details
Authors: Carvalho De Almeida, C., Muñoz Morales, Martín, Sáez Jiménez, Cristina, Cañizares Cañizares, Pablo, Martínez Huitle, Carlos Alberto, Rodrigo Rodrigo, Manuel Andrés
Format: article
Publication Date:2019
Country:España
Institution:Universidad de Castilla-La Mancha
Repository:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/29297
Online Access:https://doi.org/10.1016/j.jhazmat.2019.02.048
http://hdl.handle.net/10578/29297
Access Level:Open access
Keyword:Soil washing
Clopyralid
Electrolysis
Diamond anodes
ZVI dehalogenation
Description
Summary:In this work, a new soil washing process in which Soil-Liquid extraction technology is enhanced by adding iron particles (zero valent iron nanoparticles or granules) was investigated to remove clopyralid from spiked soils. This novel approach can be efficiently used to extract chlorinated hydrocarbons from soil and aims to obtain soil-washing wastes with low content of hazardous chlorinated species. The iron particles used were subsequently removed from the treated soil using magnetic fields. Then, the complete mineralization of the produced soil washing effluents was successfully achieved by applying anodic oxidation with diamond anodes in an electrochemical flow cell. Results demonstrated that, opposite to what it was initially expected, no improvements in the efficiency of the electrochemical process were observed by adding iron particles during the soil washing. This behavior is explained in terms of the lower electrochemical reactivity of the dechlorinated derivatives produced. Although results are not as promising as initially expected, it does not mean a completely negative outcome for the use of ZVI during washing, because the hazardousness of the pollutants is rapidly decreased in the initial stages of the soil-washing, opening the possibility for the combination of this technology with other processes, such as biological treatment.