Assessment of Heavy Metal and Selenium Levels in Leachates and Soils of Central Bank of Nigeria Dumpsite Makurdi

Abstract

Leachates from dumpsite basically contain a wide range of heavy metals and selenium. However, heavy metals have negative public health and environmental impacts once the leachates are allowed to infiltrate into groundwater. This is one of the oldest, growing problems threatening the surrounding globally. Therefore, it is imperative to quantify the information on the environmental impact of heavy metal and selenium levels, and suggesting various techniques that could be used to clean-up their concentrations from the environment to the minimum to ameliorate the plight of the people. The aim of this study was to determine the concentration of heavy metal and selenium levels in leachate of Central Bank of Nigeria dumpsite along University of Agriculture Road-Makurdi and also to investigate their levels in soil around the dumpsite platform. The concentrations of some heavy metals such as Chromium (Cr), Lead (Pb), Cadmium (Cd), Mercury (Hg) and non metal Selenium (Se) levels in leachate from Central Bank of Nigeria Dumpsite platform and surrounding soil along University of Agriculture road, Makurdi, were determined using Atomic absorption spectrophotometry (Flame AAS) for Cr, Pb and Cd while cold vapour and hydride generation were used for Hg and Se respectively. The soil samples were collected at different depths (cm) 0 – 20, 20 – 40, 40 – 60 and 60 – 80. The levels of all heavy metals and non metal selenium in this study area were found to be higher than those of the control samples. The total mean concentration of the soil samples analysed for each metal and selenium levels at different depths range from Cr (74.7 – 2.6 mg/kg), Cd (7.41 – 0.6 mg/kg), Hg (4.45 – 1.4 mg/kg), Se (2.04 – 1.2 mg/kg) and Pb (8.53 – 1.7 mg/kg). The concentrations in leachates were Cr (0.079 mg/L), Cd (0.010 mg/L), but Pb, Hg and Se were not detected. The concentrations of Cr and Cd determined in leachate were below the WHO standard limits. Similarly, the concentrations of Pb, Hg and Se in soil analyzed in this study were within the permissible limits. However, the concentration of Cr and Cd were found to be higher than the permissible limits due to the increasing anthropogenic activities in the area. Awareness of the level of soil and leachate pollution around the dumpsite needs to be created urgently especially among people living in the environment. Proper and effective waste management plan should be developed and implemented.