Uptake and Acropetal Translocation of Polycyclic Aromatic Hydrocarbons by Wheat (Triticum aestivum L.) Grown in Field-Contaminated Soil

Abstract

Uptake and acropetal translocation of 14 priority polycyclic aromatic hydrocarbons (PAHs) by wheat (Triticum aestivum L.) grown in 15 field-contaminated soils were investigated in a growth chamber. PAH concentrations in roots correlated positively with the corresponding concentrations in soils and negatively with the contents of soil organic carbon (p < 0.01). No clear linear relationship was found between log RCF (root concentration factor, µg g -1 root/µg g -1 soil on dry weight basis) and log K ow of these PAHs. Four-ring PAHs had the highest tendency to be taken up by roots. PAH concentrations in shoots correlated well with their concentrations in soils and roots. Furthermore, distribution profiles of PAHs in shoots were fairly similar to those in soils. Acropetal translocation of 10 PAHs (with log K ow varying from 3.45 to 5.78) was also implicated by R t (ratio of PAH from root-to-shoot translocation to the total accumulation in shoots) ranging from 53.6 to 72.6%. A negative linear relationship was found between log R t and log K ow of these PAHs (p < 0.01), and acropetal translocation of PAHs depended on their chemical properties.

Field study on the uptake and translocation of perfluoroalkyl acids (PFAAs) by wheat (Triticum aestivum L.) grown in biosolids-amended soils

“…The lipid concentration of wheat roots was found to be 2.18%. The RLOMAFs ranged from 1.05 to 4.55, which were higher than those of polybrominated diphenyl ethers (PBDEs, 0.02e0.71, Huang et al, 2011), but was similar to 4-ring polycyclic aromatic hydrocarbons (PAHs, 1.59e2.66, Tao et al, 2009). Yoo et al (2011) suggested that the transfer potential of long-chain PFCAs from soils to plants was lower than that of short-chain PFCAs.…”

“…Organic contaminants reach aerial plant organs in two ways: from the air and with the transpiration stream (Huang et al, 2010;Tao et al, 2009). It is possible that PFAAs in the soils evaporate into the ambient air and enter plants via gaseous uptake, contributing to their accumulation in the above-ground part of wheat, because PFAAs can be detected in the atmosphere (Li et al, 2011;Ahrens et al, 2011), though they do not readily volatize ).…”

“…An alternative pathway for PFAAs transport is via aerial transport of volatile PFAA precursors with subsequent oxidation of the plantbound PFAA precursors, such as fluorotelomer alcohols (FTOHs) or 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFO-SAA), to form PFAAs (Yoo et al, 2011). In order to identify the contribution of acropetal transport of PFAAs to their accumulation in aerial plant organs, PFAA concentrations in the control plants were determined and considered to be due to their gaseous uptake, on the assumption that PFAAs evenly diffuse in the ambient air and equally absorb onto aerial plant organs of biosolids-treated plants and their nearby blank control plants (Tao et al, 2009). The results showed that PFAA concentrations in wheat straws, husks and grains of control are lower than MLD (Table 3), suggesting that the effect of aerial transport of PFAAs and the oxidation of absorbed PFAA precursors on PFAA accumulation is negligible.…”

“…The RSD of ROMCFs were lower than those of RCFs (9.04e46.1%), which indicated that SOM is one of the important factors limiting the uptake of PFAAs by wheat roots. It is suggested that the uptake of HOCs by plant roots is mainly characterized by lipid dominating partition processes and might be expected to be similar to their accumulation by lipid containing passive samplers (Huang et al, 2010;Tao et al, 2009). The root lipid/organic matter accumulation factors (RLOMCFs, (ng/ g root lipid )/(ng/g SOM )) on the basis of root lipid and SOM ((C root /C lipid )/(C soil /C SOM )) were calculated (Table S4) in order to make a comparison, though it is reported that lipid is not the main compartment of PFAAs in animals and fish (Peng et al, 2010;Hoff et al, 2003).…”

Phytoremediation of PAHs-contaminated Sludge in a Constructed Wetland

“…Pahs include a variety family of more than 200 organic contaminants, most of which are carcinogenic and mutagenic [1].…”