Exploiting Phytoremediation as a Technique for Conservation of Bitumen Polluted Soil
No Thumbnail Available
Date
2018-10-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Tropical Forest Resources
Abstract
Toxic metal pollution of soil is a major environmental problem bedeviling soil conservation that most conventional remediation approaches cannot solve. High concentrations of heavy metals have both
environmental and toxicological effects. This infringes on the integrity of ecosystems by affecting indices such as plant abundance and diversity. The study was conducted in the Ode-Irele bitumen belt of Ondo State, Nigeria, where there are bitumen seepages and exploratory activities, and Ebute-Irele, without any record of bitumen seepages, served as a control. Composite samples of bitumen, soils contaminated with bitumen, and plants naturally growing on bitumen seepage and exploratory sites were collected for the determination of heavy metal concentrations using atomic absorption spectrometry. The result showed that more metals were significantly higher in soils and bitumen samples than in plants of the exploratory site than the seepage site. Mn, 870.00±197.99mg/kg, Cu, 215±21.21mg/kg, Zn, 290.00±56.57mg/kg, Cd, 3.50±0.71mg/kg, V, 10.00±0.00mg/kg, and As, 5.00±0.00mg/kg were significantly higher in exploratory surface soil than 571.83±112.93mg/kg, 39.67±8.89mg/kg, 86.43±8.56mg/kg, 3.17±0.57mg/kg, 0.37±0.18mg/kg, 7.93± 0.57, and 3.83±0.12mg/kg respectively in plants. The result of the mean difference of heavy metals between plants on exploratory bitumen site and bitumen sample also showed that Cu, 192.50±23.33mg/kg, Zn, 244.25±47.73mg/kg, Pb, 7.80±1.27mg/kg, Cd, 3.60±0.29mg/kg, and As, 4.60±0.42mg/kg in bitumen sample were significantly higher than 39.67±8.89mg/kg, 86.43±8.56mg/kg, 3.17±0.57mg/kg, 0.37±0.18mg/kg, and 0.38±0.12mg/kg respectively in plants on the exploratory site. However, V, 7.93±0.57mg/kg was significantly higher in plants than 6.00±1.27mg/kg in the bitumen sample. The result of the mean difference of heavy metals between plants on exploratory site and bitumen sample further showed that Cu, 192.50±23.33mg/kg, Zn, 244.25±47.73mg/kg, Pb, 7.80±1.27mg/kg, Cd, 3.60±0.29mg/kg, and As, 4.60±0.42mg/kg in bitumen sample were significantly higher than 39.67±8.89mg/kg, 86.43±8.56mg/kg, 3.17±0.57mg/kg, 0.37±0.18mg/kg, and 0.38±0.12mg/kg respectively in plants on the exploratory site. However, V, 7.93±0.57mg/kg was significantly higher in plants than 6.00±1.27mg/kg in the bitumen sample. The higher values of heavy metals in soils and bitumen samples over corresponding values in plants were possibly due to plants’ ability to accumulate and gradually remove the metals from their tissues, a process known as phytodegradation or rhizodegradation. Panicum laxum (56.5 %) and Lycopodium carenum (43.7%) were the most abundant plants that naturally grow on seepage and exploratory sites, respectively. The plants found naturally growing on bitumen-polluted soil have the capacity to hyperaccumulate heavy metals and so should be used for the remediation of bitumen-polluted soil.
Citation
Description
Keywords
Citation
Ogunsusi, K. and Adeleke, B.O. (2018). Exploiting phytoremediation as a technique for conservation of bitumen polluted soil. Journal of Tropical forest Resources, 34: 10-23