Heavy metal concentrations levels in groundwater and wastewater sources in parts of Trans-Amadi, Port Harcourt, Nigeria

Abstract

This research assesses the concentration levels of heavy metals in parts of Trans-Amadi Layout, Port Harcourt, Nigeria. Standard sampling and analytical method were employed in the study. Geochemically significant concentrations of lead (Pb2+) and iron (Fe²+ and Fe³+) prevail in about 70% of the functioning domestic water supply wells in Trans Amadi, Port Harcourt, while traces of Mercury and Arsenic (with relatively high concentration of lead and Iron) characterize industrial effluent liquid wastes (usually discharged untreated into the environment). The major industries in Trans Amadi industrial layout area of Port Harcourt ( in addition to breweries and mineral water industries) produce wide range of pharmaceuticals, cosmetics and textiles, with elevated potential to release chemical waste such as oxides of mercury, iron and titanium; silicates of magnesium and aluminum, phosphates; and sulphates (such as FeSO4 used as coagulates in water treatment) into the environment of common sight along the streets and waste sites are metallic cans from food items, old and worn out rubber, leather and machine parts, variable sizes of broken metallic, plastic and asbestos pipes and enamel wares, as well as a wide range of used textile materials. Enrichment of heavy metallic ions in urban waters in non-mineralized areas is controlled by chemical activities on these wastes. Liquid wastes from industrial and municipal sources are commonly discharged (untreated) along road sides and streets where they constitute shallow ponds, or flow at a very slow rate (depending on flow volume and slope) to a distant termination point (mostly the river and stream flow channels). The liquid wastes, with suspended gaseous wastes from automobiles and industrial and domestic machine engines, are linked to the groundwater zone through recharge by meteoric waters. This accounts for the worrisome concentration of lead (Pb) in the groundwater in the area, without geologically-proven mineralization of lead and base metals.