Biodegradation of 2,4-dichlorophenol in the presence of volatile organic compounds in soils under different vegetation types

It has been suggested that monoterpenes emitted within the soil profile, either by roots or by decaying biomass, may enhance the biodegradation of organic pollutants. The aim of this study was to evaluate the effect of biogenic volatile organic compounds (VOCs) on the catabolism of 2,4-dichlorophenol in soils. Soils were collected from areas surrounding monoterpene (woodland) and nonmonoterpene (grassland)-emitting vegetation types. Soils were spiked with [UL-C-14] 2,4-dichlorophenol at 10 mg kg(-1) and amended with alpha-pinene, p-cymene or a mix of monoterpenes (alpha-pinene, limonene and p-cymene in 1 : 1 : 1 ratio). The effects of monoterpene addition on the catabolism of [UL-C-14] 2,4-dichlorophenol to (CO2)-C-14 by indigenous soil microbial communities were assessed in freshly spiked and 4-week-aged soils. It was found that aged woodland soils exhibited a higher level of [UL-C-14] 2,4-dichlorophenol degradation, which was subsequently enhanced by the addition of monoterpenes (P < 0.001), with the VOC mix and alpha-pinene amendments showing increased [UL-C-14] 2,4-dichlorophenol catabolism. This study supports claims that the addition of biogenic VOCs to soils enhances the degradation of xenobiotic contaminants.