Mobility of traffic-related Pd and Pt species in soils evaluated by sequential extraction. (November 2018)

• Record Type: Journal Article
• Authors: Leopold, Kerstin; Denzel, Aline; Gruber, Andreas; Malle, Lisa
• Is Part Of: Environmental pollution. Volume 242(2018)Part B
• Page Start: 1119
• Page End: 1127
• Publication Date: 2018-11
• Subjects: Platinum group metals (PGM) -- Car exhaust emissions -- Sequential extraction -- Mobility in soils -- Risk assessment code -- Migration of PGM in soils; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2018.07.130
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The aim of this study was to evaluate the mobility of platinum (Pt) and palladium (Pd) emissions from automotive catalysts in soils and to contribute to the risk assessment of platinum group metals (PGMs) discharged from catalysts in the environment. To address this question, for the first time risk assessment code (RAC) was applied to consider the results from sequential extraction of different Pd and Pt species from soils. For this purpose, model soil samples were prepared spiking defined Pd or Pt species, respectively, at known concentrations. In order to mimic emitted species as well as possible transformation products of traffic-related Pd and Pt emissions in soils, coated and uncoated elemental nanoparticles (cPd/cPt NPs, Pd/Pt NPs) and ionic divalent metal species (Pd(II)/Pt(II)) were applied. All model samples were characterized in detail and the developed sequential extraction scheme was validated. RAC values ranged between 24 and 8% revealing medium to low risk. The order of mobility for the studied species was found to be Pt(II) > cPd NPs » Pd(II) > Pd NPs > Pt NPs > cPt NPs. Furthermore, migration of Pd species in gravity columns was studied confirming highest transport of cPd NPs. Graphical abstract: Image 1 Highlights: Mobility of traffic-related Pd and Pt species in soils were studied. Clear differences in their mobility were observed. Mobility follows the order: Pt(II) > cPd NPs » Pd(II) > Pd NPs > Pt NPs > cPt NPs. Species-specific Risk Assessment Code values were calculated ranging from 8 to 24%. Migration of particles seem to provide a dominant transport procedure in soils. Abstract : Mobility of traffic-related Pd and Pt emissions in soils depends on their species and evaluation by risk assessment code gives values ranging from 8 to 24%, hence medium risk potentials.