Vegetation/Soil Distribution of Semivolatile Organic Compounds in Relation to Their Physicochemical Properties

Abstract

The concentrations (C) of several semivolatile organic compounds (SOCs) in Norway spruce needles (N) and in the local humus horizon (O) of 25 remote Austrian forest sites were used to calculate an ecosystem-oriented partition coefficient needles/humus horizon (C N /C O ). Between 66 and 78% of the compounds' variation of this quotient could be explained by each of the following physicochemical parameters: vapor pressure (p S ) and the partition coefficients n-octanol/water (K OW ), n-octanol/air (K OA ), and adsorbed/ dissolved in soil (K OC ) of the compounds. This result further underlines the usefulness of these parameters for predicting the behavior of SOCs in terrestrial ecosystems. Compounds with low p S and high K OW , K OA , and K OC show a very low C N /C O quotient, which implies a higher accumulation of these compounds in the O horizon than in the needles. The role of forest soils as sink for these SOCs is demonstrated. Alternatively, C N /C O > 1, due to higher concentrations in the needles than in the O horizon, have been shown for SOCs with comparably high p S and low K OW , K OA , and K OC . In this respect, the possible role of revolatilization of the more volatile SOCs from soils to needles is discussed. In the mineral soil layers below the O horizon, SOCs with lower K OC and better water solubility tend to be less accumulated. However, if all investigated compounds are taken into consideration, accumulation in the mineral soil layers showed no general trend in relation to the selected physicochemical parameters.

Organochlorine pesticides (DDTs and HCHs) in soils from the outskirts of Beijing, China

“…OCP residues have been studied in different soil horizons (Boul et al, 1994;Miglioranza et al, 1999;Weiss, 2000;Feng et al, 2003), and much attention was paid to the shallow subsurface soils. There are very limited data available for the deep soil layers, which is an indicator of potentiality of OCPs present in the groundwater contamination.…”

Interactions of mixed organic contaminants in uptake by rice seedlings

“…The need for better understanding the mechanism and influential factors on plant uptake has prompted a series of studies on the plant-uptake process in recent times (Riederer, 1990;Paterson et al, 1994;Trapp, 1995;Trapp and Mathies, 1995;Burken and Schnoor, 1997;Weiss, 2000;Li et al, 2002Li et al, , 2005Wild et al, 2005). Analyses of the concentrations of nonionic contaminants in plants in relation to the external levels in water (or soil solution) from extensive sources have revealed that these contaminants enter plants largely via a passive (i.e., partition) process (Briggs et al, 1982;Chiou et al, 2001;Trapp, 2004;Su and Zhu, 2006).…”

Interaction between cadmium and atrazine during uptake by rice seedlings (Oryza sativa L.)

“…There has been a considerable interest in understanding the uptake of organic contaminants by plants during the last two decades (Briggs et al, 1982;Trapp and Matthies, 1995;Weiss, 2000;Chiou et al, 2001;Li et al, 2002;Trapp, 2004). Plants could be exposed to contaminants in different ways.…”