Importance of surface roughness on perï¬uorooctanoic acid (PFOA) transport in unsaturated porous media.
Environ Pollut
; 266(Pt 1): 115343, 2020 Nov.
Article
em En
| MEDLINE
| ID: mdl-32814265
Understanding the subsurface transport of perï¬uorooctanoic acid (PFOA) is of considerable interest for evaluating its potential risks to humans and ecosystems. In this study, packed-column experiments were conducted to examine the influence of surface roughness on PFOA transport in unsaturated glass beads, quartz sand and limestone porous media. Results showed decreasing moisture content significantly increased the air-water interfacial adsorption of PFOA and led to greater retardation in all three types of porous media. Particularly, rougher surface (limestone > quartz sand > glass beads) and smaller grain size (i.e. a larger solid specific surface area, SSSA) significantly enhanced PFOA retardation under unsaturated conditions. These results were further supported by bubble column experiments and SSSA analysis of porous media, which demonstrate that except for the factors affecting PFOA transport in solid-water interface (e.g. surface charge and chemical heterogeneity), the greater retardation of PFOA during transport is attributed to the larger air-water interfacial areas associated with rougher surface and smaller grain size and hence greater interfacial adsorption of PFOA. Our results indicated the importance of surface roughness on the retention and transport of PFOA in the unsaturated zone.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ecossistema
/
Dióxido de Silício
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article