PHYTOACCUMULATION OF HEAVY METALS IN AN OIL-SPIKED SOIL BY Vernonia amygdalina AFTER EXPOSURE TO SODIUM AZIDE SOLUTIONS

This study investigated the effects of sodium azide pre-treatment Vernonia amygdalina stem cuttings on bioaccumulation heavy metals in a waste engine oil-contaminated soil. Top soil was collected and sun-dried to constant weight. Soil then mixed thoroughly with oil (WEO) weight basis, obtain 4% w/w concentration. Soils were left attenuate for 1 week (WAP). Sodium solution prepared concentrations 0.125, 2.50 5.00 % w/v respectively. The control distilled water. At WAP, equally-cut that had originally been entirely immersed solutions one hour transferred into oil-polluted Results showed at 150 days after sowing, pretreatment significant impact plant growth development respect height (58.0 – 78.4 cm) chlorophyll index, which ranged from 16.8 24.3 CCI polluted soil, compared 17.8 control. Although Cr, V, Mn Cu never detected leaves stems, Pb Ni both treated plants. 5% NaN3-treated accumulated 13.80 mg/kg 0.32 leaves, as well 13.84 3.98 stems. Upon azide, V. significantly bioaccumulated Ni, other metals.