US EPA

2321123 

Journal Article 

INFLUENCE OF PLANT ROOT EXUDATES ON THE MOBILITY OF FUEL VOLATILE COMPOUNDS IN CONTAMINATED SOILS 

Balseiro-Romero, M; Kidd, PS; Monterroso, C 

2014 

Yes 

International Journal of Phytoremediation
ISSN: 1522-6514
EISSN: 1549-7879 

16 

7-8 

824-839 

English 

24933887 

10.1080/15226514.2013.856851 

WOS:000329510200014 

Vegetation and its associated microorganisms play an important role in the behaviour of soil contaminants. One of the most important elements is root exudation, since it can affect the mobility, and therefore, the bioavailability of soil contaminants. In this study, we evaluated the influence of root exudates on the mobility of fuel derived compounds in contaminated soils. Samples of humic acid, montmorillonite, and an A horizon from an alumi-umbric Cambisol were contaminated with volatile contaminants present in fuel: oxygenates (MTBE and ETBE) and monoaromatic compounds (benzene, toluene, ethylbenzene and xylene). Natural root exudates obtained from Holcus lanatus and Cytisus striatus and ten artificial exudates (components frequently found in natural exudates) were added to the samples, individually and as a mixture, to evaluate their effects on contaminant mobility. Fuel compounds were analyzed by headspace-gas chromatography-mass spectrometry. In general, the addition of natural and artificial exudates increased the mobility of all contaminants in humic acid. In A horizon and montmorillonite, natural or artificial exudates (as a mixture) decreased the contaminant mobility. However, artificial exudates individually had different effects: carboxylic components increased and phenolic components decreased the contaminant mobility. These results established a base for developing and improving phytoremediation processes of fuel-contaminated soils. 

plant root exudates; BTEX and fuel oxygenates; contaminant mobility in soil