Phytoremediation potential of velvet bean (Mucuna prurens L. DC) and maize (Zea mays L.) on petroleum product polluted soil

Abstract

Phytoremediation potential of Velvet bean and Maize was carried out at the University of Port Harcourt, Botanic Garden. The seeds where grown in different soil bags of 20kg and polluted with 1000ml each of different treatment of AGO,
PMS and DPK. The values of Heavy metal concentration in the soil was assessed and analyzed for Zn, Fe and Cu. Velvet bean and maize in AGO contaminated soil (Fe: 355g/ml., Zn: 240g/ml and Cu: 100g/ml., PMS soil (Fe: 75.0g/ml, Zn: 3.0g/ml, and Cu:155.5g/ml), DPK soil (Fe: 150g/ml, Zn: 30.0g/ml, Cu 150g/ml). After 12 weeks of planting velvet bean, heavy metal in AGO contaminated soil (Fe 170.5g/ml, Zn 100.5g/ml and Cu 60.4g/ml), PMS soil (Fe 60.5g/ml, Zn 2.0g/ml and Cu 101g/ml), DPK soil, (Fe 103g/ml, Zn 24.8g/ml and Cu 55.0g/ml). For Maize soil, the heavy metals in AGO soil (Fe 350g/ml, Zn 220g/ml and Cu 105g/ml)., PMS soil (Fe 70.0g/ml, Zn 2.3g/ml and Cu 110g/ml)., DPK soil, (Fe 105.5g/ml, Zn 27.2g/ml and Cu 75.5g/ml. At harvest, the result of plant height showed a gradual increase in PMS concentration of velvet bean than AGO and DPK.
Differences were not recorded for number of leaves and Leaf Area. Also the different treatment of petroleum product on maize showed reduction in yield after harvest. However unpolluted (control) soil gave the highest total plant height and highest biomass value. Velvet bean had a better phytoremediation potential to maize as AGO, PMS and DKP showed more deleterious effect on maize plant by interfering with the physiology and metabolic activity of the plant.