Bioremediation of Heavy Metals in Contaminated Soil from Abandoned Asa Dam Road Dumpsite

The dispersion pattern of heavy metals in soils surrounding municipal solid waste dumps was studied in a major area at Asa Dam Road, Ilorin, Kwara State. Soil samples were collected at three depths i.e.,0-15, 15-30 and 30-45 cm. The bioremediation capacity of five plants (Amaranthushybridus, Celosia agentea, Tithoniadiversifolia, Manihotescunlenta, Ipomeabatatas) grown on the dumpsite were studied for different metals. The moisture contents of the soil samples and plants were 4.55 - 18.58% and 3.75 - 13.78% respectively. The pH of soil and plants ash contents was in the range of 6.7 – 7.5 and 6.35 – 21.0 respectively. Atomic Absorption Spectroscopy method was employed in the determination of the concentration of Fe, Ca, Mg, Zn, Cd, Ca and Pb in both plant and soil samples. Amaranthushybridus and Celosia agentea were found to hyper-bioaccumulate, Tithoniadiversifoliabioaccumulate heavy metals mildly while Manihotescunlenta hyper-accumulate Iron. Cadmium and Lead were not detected in the plants. Nitrate concentration increases progressively down the soil profile and highest in Tithoniadiversifolia among the plants.