EVALUATION OF SOME SELECTED PLANT SPECIES
AS PHYTOREMEDIATING AGENT FOR
CONTAMINATED SOIL.
O.O Awotoye, O.R Ogunbanjo, F.B Okanlawon.
Federal College of Forestry,
P.M.B.5054, Jericho Hill, Ibadan, Oyo State, Nigeria.
Land and water are precious natural resources on which rely sustainability of Agriculture and civilization of
human race, but unfortunately, both have been subjected to pollution as a result of man’s activities. In some
regions across the world, problems with degraded contaminated soils as well as waste management are
rather too complex, thus, it is has been an important global issue and consequently leading to an adverse
impact on Agricultural productivity, food security and the environment at large.
The direct use of green plant and their associated micro organisms to stabilize or reduce contamination
in soils, sludges, sediments, surface water or ground water is described as phytoremediation. It is an
inexpensive, solar energy driven, cleaning up technique and it is considered one of the most useful effective
method of removing heavy metal contaminants from soils. It has been reported that such species for
phytoremediation can tolerate high concentration of heavy metals, they are fast growing and as well
accumulate high amount of heavy metals in their parts.
This paper therefore discussed the effectiveness of some selected plant species (Adansonia
digitata,Jatropha curcas, and Hildergadia barteri) in the absorption of heavy metals from contaminated
soils. The experimental design was a 3×3 Factorial and Completely Randomized and divided into three
treatments which were replicated fifteen times. The result indicated that there is a significant difference in
the absorption of heavy metals by the tree species, with Jatropha curcas having the highest value of 0.9867
mg/kg, followed by Adansonia digitata with 0.6058 mg/kg and Hildergadia barteri with a value of 0.3490
mg/kg. There is a significant difference in the absorption of heavy metals by the different parts of the plants.
The roots of the three plants was also observed to absorb the highest level of heavy metals with a value of
1.2233 mg/kg, followed by the stem with 0.3700 mg/kg and the leaves 0.2567 mg/kg. Conclusion was
however made based on the findings of the research.
Keywords: Phytoremediation, heavy metal contamination, tree species, absorption rate.