Surface water contamination by heavy metals from Enyigba Pb-Zn mine district, southeastern Nigeria using metal enrichment and pollution indices.

Abstract

A total of twelve (12) surface water samples were collected from the Enyigba Pb/Zn mining district to assess the contamination of the water sources by heavy metals as a result of mining of lead and zinc minerals in the area. The samples were acidified to stabilize the metals for periods more than four days without the use of refrigeration. The acidified surface water samples were analysed by a commercial laboratory at Projects Development Institute (PRODA), Enugu using Atomic Absorption Spectroscopy (AAS). The elements analysed for are lead (Pb), zinc (Zn), copper (Cu), arsenic (As), cadmium (Cd), nickel (Ni), manganese (Mn) and cobalt (Co). The result and analysis based on metal enrichment and pollution indices (MEI and MPI) indicate that the MEI of As, Cd, Pb and Ni are very high in the surface water and all contributed to very slight pollution of the surface water based on metal pollution index.