Heavy metal pollution in soil and plants at bone char site

Abstract

This study determined the heavy metal concentration in soil and plants at a bone char site in Umuahia, Nigeria. Soil and plant samples collected in a randomized complete block design (RCBD) were analyzed for zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), and arsenic (As). The concentration of metals in soil and plants in the vicinity of the bone char site are as follows: Zn (172 mg kg−1) and Ni (0.62 mg kg−1) in soil were highest at site P3, Pb (2.37 mg kg−1) and As (0.08 mg kg−1) at site P1, and Cd (18.30 mg kg−1) at site P2. In plants, the concentrations of Zn (41.17 mg kg−1) and Cd (3 mg kg−1) were highest in Albizia ferruginea, Ni in Dialium guineense (0.09 mg kg−1), while Pb was in D. guineense (0.08 mg kg−1) and Spathodea companulata (0.06 mg kg−1). The levels of Zn, Cd, Pb, Ni, and As in soil ranged from 11.2 to 172, 2.68 to 18.2, 0.026 to 2.37, 0.33 to 0.62, and 0.02 to 0.08 mg kg−1, respectively. In plants, the concentration of Zn, Cd, Pb, and Ni ranged from 2.01 to 41.17, 0.12 to 3, 0.02 to 0.08, and 0.03 to 0.09 mg kg−1, respectively. There were significant correlations between Zn and Cd, and Pb and As in soil. The high concentration of Cd in soil might affect soil productivity.