Heavy Metal Contamination of Soil and Surface Water in the Arufu Lead-Zinc Mining District, Middle Benue Trough, Nigeria

Abstract

This paper is aimed at investigating the nature of heavy metals dispersion in soil and surface water around the Arufu leadzinc mine, Middle Benue Trough, Nigeria. Rock samples from mine pits and adjoining outcrops as well as water samples from mine pits and adjacent streams were collected and analyzed. Also analysed were soil samples collected from mine waste and adjoining areas as well as from a forest to serve as control. All samples were analysed for Fe, Zn, Mn, Cu, Pb, Cr, As, Cd and Ag, using atomic absorption spectrophotometer (AAS). Organic Matter (OM) content of the soil samples, and the pH of both soil and water samples were also determined. The results show that the OM content of soil was generally low (4 + 1.1%) and both soil and water samples were characterized by moderate pH values of 6.30 to 8.00 and 5.60 to 7.80 respectively. Furthermore, soils developed over bedrock show normal (background) levels of heavy metals, while soils developed over mine waste are enriched in Zn (181 + 83 mg/kg); Pb (40 + 28 mg/kg) and Cd (3 + 2 mg/kg). Also, water samples from mine ponds are enriched in Pb (0.02 -0.10 mg/1) and Cd (0.02 -0.04 mg/1). The sources of these heavy metals are most probably sulphides in the mine waste. Tailing and mine pits may therefore represent point sources of heavy metal contaminants and should therefore be reclaimed to prevent further contamination.

Neo- and Paleo-Limnological Studies on Diatom and Cladoceran Communities of Subsidence Ponds Affected by Mine Waters (S. Poland)

“…In contrary to the water, sediments were extremely contaminated by Cd, Pb, and Zn (according to values of I geo , [35]) reaching levels found in water bodies affected by active and closed Zn and Pb mines [14,40,41,43]. This confirms that sediments of waters in mining areas act as long-term sinks for heavy metals [44,45].…”

“…However, it should be emphasized that even during small floods all ponds (CH1-CH3) are flooded with river water. Similarly to macroions, the total Cd, Pb, Zn, and Cu concentrations in the studied waters were predominantly close to values from industrialized areas [39]; nevertheless, they were much lower than in aquatic systems polluted by active Zn and Pb mining [40,41]. The concentrations of dissolved Cd did not exceed permissible values for priority substances, while dissolved Cu and Zn were not higher than permissible country values for substances harmful to the aquatic environment [42].…”

Genome instability in Chironomus annularius sensu Strenzke (Diptera, Chironomidae): A biomarker for assessment of the heavy metal contaminants in Poland

“…The sediments from the River Chechło kilometers downstream of the disused mine remain heavily contaminated to a degree which is typical of freshwater sediments polluted by active and disused Zn and Pb mines (Audry et al, 2004;Adamu and Nganje, 2010;Ciszewski et al, 2013;. High heavy metal pollution was present also in the sediments of the pond where contaminants have been stored since the mining era.…”