Comparison of PAHs uptake by selected Monocotyledones and Dicotyledones from municipal and industrial sewage sludge.

Barbara Gworek,Katarzyna Klimczak,Marta Kijeńska,Dariusz Gozdowski

doi:10.1007/s11356-016-7130-2

Abstract

The study was focused on two goals: (i) the confirmation of the existence of a general relation between the content of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and in plants growing in it, regardless of the type and content of sewage sludge, and (ii) if so, the answer to the question whether the uptake of PAHs by plants depends on their type. To realize the set aims, the contents of PAHs in four differentiated plant species were measured, two belonging to the Monocotyledones and two belonging to Dicotyledones group, growing in municipal and industrial sewage sludge in two locations. All the investigations were carried out during the period of 3 years. The results clearly demonstrated that the uptake of PAHs by a plant depended on polyaromatic hydrocarbon concentration in the sewage sludge. The relation between accumulation coefficient of PAHs in plant material vs. the content of PAH in sewage sludge was of exponential character. The results indicate that in case of four- and five-ring PAHs, the root uptake mechanism from soil solution occurs, regardless of the type and origin of sewage sludge and the type of plant. For three-ring PAHs, we can assume for Monocotyledones that the root uptake mechanism occurs because we observe a significant correlation between the content of fluorene, phenanthrene, and anthracene in plant material and in the sewage sludge. For Dicotyledones, the correlation is insignificant, and in this case probably two mechanisms occur—the uptake by roots and by leaves.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants and constitute the largest class of suspected carcinogens and mutagens
The relation between PAH accumulation coefficient in plant material vs. the PAH content in sewage sludge was of exponential character
The results indicate that for four- and five-ring PAHs, the root uptake mechanism from soil solution occurs, irrespective of the type and origin of sewage sludge and the content of PAHs in it and irrespective of the type of plant

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants and constitute the largest class of suspected carcinogens and mutagens (van Metre and Mahler 2003) They appear in the environment and originate from natural sources (like forest fires), but most of their emission is connected with human activity (Benner and Gordon 1989; Garcia et al 2012; Harvey et al 2002; Lim et al 1999; Weisman et al 2010; Wild and Jones 1995) or, sometimes, human activity influences the mobility of PAHs in the environment (Zuijdgeest and Huettel 2012). The most studied and most known compound of the group is benzo[a]pyrene (Dutta et al 2010), but it is to highlight that PAH compounds never exist alone—they always occur in a mixture, which was confirmed in many experiments (Mumtaz and George 1995)

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