Abstract

Understanding the process of contaminant accumulation by plants is essential to assessing crop contamination; organic chemicals may be adsorbed to roots and then be taken up, translocated, metabolized, or transpired by plants. The biosorption of phenanthrene by the radical system of Cyperus hermaphroditus,was studied by plants exposed to different concentrations of this pollutant, during 3 and 12 days and phenanthrene adsorbed was detected by optical and scanning electron microscopy (SEM) techniques and measured by photoacoustic spectroscopy (PAS). The sorption of phenanthrene in this species increased with plant age and the exposition time to the contaminant, due to the root mass with more surface area that enhanced affinity of the roots for the contaminant. The radical system of C. hermaphroditus may thus provide a surface for phenanthrene biosorption; that could be an important control in the immobilization of polycyclic aromatic hydrocarbons.

Key words:  Phenanthrene, radical system, photoacoustic spectroscopy.