ABSTRACT
The study assessed the influence of battery charging activity (BCA) on soil heavy metal concentrations at depths 0-15 cm; 15 - 30cm and their uptake by a selected plant (Amaranthus spp) in two cities (Lagos and Ibadan) of Nigeria. Heavy metals (Pb, Ni, Cd and Cr) in soil and plant digests were measured using atomic absorption spectrophotometer. Soil properties (pH, organic matter, organic carbon and particle size distributions) were analyzed via standard analytical procedures and correlated with metal concentrations. Results showed BCA increased soil and plant metal concentrations, respectively, by factors of 53 - 260; 7.49 - 15.37 for Pb, 2.19 - 4.99; 2.01 - 2.15 for Ni, 2.40 - 5.20; 1.25 - 1.94 for Cd and 2.04 - 4.67; 0.42 - 1.76 for Cr. Study revealed that Pb the dominant pollutant in the two cities but the incremental factor, for each metal relative to the control, was higher in Ibadan than in Lagos. Based on the bio-concentration factor of 0.127 - 0.395, phyto-hyperaccumulation was not obtained. Correlations showed that quantitative battery waste generation was directly associated with soil metal concentrations especially Pb whose coefficient ranged from 0.846 to 0.901 (p ? 0.002), revealing that the consequent metal phytoavailability was more dependent on soil properties than quantitative battery release.
Keywords: Battery charging, Heavy metals, Soil, Plant uptake, Environmental assessment.