Removal Potentials of Heavy Metals by Cassava Peels, Parts of Pawpaw Plant, Coconut Husk, Guinea Corn Chaff, and Pineapple Peels from Bonny Light Crude Oil Polluted Soil

Removal of environmental contamination such as heavy metals in soil, water and environment is of great importance for human welfare. Hence, the objective of this paper is to comparatively evaluate the removal potentials of heavy metals by cassava peels, parts of pawpaw plant, coconut husk, guinea corn chaff, and pineapple peels from bonny light crude oil polluted soil using appropriate standard methods. Results obtained indicated significantly high levels of heavy metals in the untreated crude oil contaminated soil at weeks 1, 8 and 12. There was a significant (P<0.05) decreasing trend in heavy metal levels in the contaminated soil after treatment with the various agro-residues after the 12-week period. The highest reduction of the heavy metals was observed in the test Group treated with a combination of the agro-residues under study; Ni (46.8%), Pb (61%), Cr (46.3%), Cd (34.1%) and As (49.8%) reduction. The results showed that the agro-residues under study can effectively enhance microbial removal of heavy metals in crude oil polluted soil.