PHYTOREMEDIATION POTENTIAL OF SENNA(Senna occidentalis) AND NEEM(Azadirachta indica) IN DETOXIFICATION OF SOILS CONTAMINATED WITH Zinc (Zn), Copper (Cu) and Lead (Pb).

Abstract

A greenhouse and laboratory experiment were carried out to investigate the phytoremediation potential of Neem (Azadirachta indica) and Senna (Senna occidentalis) plants. Soil samples were randomly collected in the teaching and research farm of the Center for Dry Land Agriculture, Bayero University Kano. Samples were collected from both plants and soil for standard analysis. The data obtained was statistically analyzed using one-way ANOVA. The result indicated that the soil was Loamy sand in texture. The soil pH was found to be moderately acidic (5.99), while the OC, TN, and Ap were found to be low. The concentrations of Zn and Cu in both plants were found to be high with mean values ranging from18.11mg/kg to 22.02mg/kg, with the root system having the highest concentration. However, Pb was not absorbed by any of the studied plants but was found in the soil samples with mean concentration of 34.01mg/kg. The bioaccumulation and translocation factors from the study indicated that the test plants can be used as phytoextractors to remediate soils contaminated with Zn and Cu. It is recommended that Neem and Senna plants should be used to detoxify soils contaminated with Zn and Cu. Also, investigation should be carried out on how to recover the extracted metals to avoid reintroduction into the environment.