Phytoremediation of water and soil contaminated with imidacloprid pesticide by Plantago major, L.

Broadleaf plantain plant (Plantago major L.) was used in phytoremediation of imidacloprid insecticide in water and soils. For the Freundlich model the constant related to the biosorption capacity (Kf) of imidaclaprid were respectively, 7.94, 6.31, and 2.51 ug/g for dry roots, fruits (seeds with shells) and leaves of broadleaf plantain plant. Viable whole broadleaf plantain plant in water solution reduced imidacloprid residues by 55.81-95.17%, during 1-10 days of exposure periods compared with 13.71-61.95% in water solution without the plantain. In water solution, imidacloprid significantly accumulated in plantain roots, leaves and fruits to reach the maximum levels after 6, 1 and 3 days of treatment, respectively. The maximum levels were 15.74, 37.21, and 5.74 ug/gm, respectively. These values were decreased to 6.95, 1.46, and 0.12 ug/ gm after 10 days of treatment. The growing cells of short-rod gram-negative bacteria that isolated from the water solution containing broadleaf plantain plants was able to induce 93.34% loss of imidacloprid as a source of both carbon and nitrogen within a short period (48 hr) compared with 31.90% in un inoculated medium. Half-life (t 1/2) in soil planted with broadleaf plantain plants and in unplanted soil were found to be 4.8 and 8.4 days, respectively.