Phytoremediation of polycyclic aromatic hydrocarbons (PAH) by cv. Crioula: A Brazilian alfalfa cultivar

This work aimed to evaluate the phytoremediation capacity of the alfalfa cultivar Crioula in soils contaminated with polycyclic aromatic hydrocarbons (PAHs), primary pollutants with mutagenic and carcinogenic potential. Alfalfa was grown from seed for 40 days on soil amended with anthracene, pyrene, and phenanthrene. Soil and plant tissue was collected for biometric assay, dry mass analysis, and PAH analysis by liquid chromatography. Increased total PAH concentration was associated with decreases in plant biomass, height, and internode length. The Crioula cultivar had a satisfactory phytoremediation effect, reducing total PAH concentration (300 ppm) in the experimental soil by 85% in 20 days, and by more than 95% in 40 days. The PAH showed a tendency to be removed in the temporal order: phenanthrene before pyrene before anthracene, and the removal ratio was influenced by the initial soil concentration of each PAH.

Extracts containing PAH were obtained from soils cultivated with Medicago sativa L. (cv. Crioula) in the presence and absence of 150, 300, and 450 ppm total of PAH (phenanthrene, anthracene, and pyrene). After ultrasonication steps and purification of PAH by silica adsorption chromatography, samples containing PAH were quantified by high-performance liquid chromatography in reverse phase. At the end of this study, it was determined that the cv. Crioula showed a satisfactory phytoremediation potential. It presented the reduction of the total of PAH at around 85% in 20 days.