Impact Assessment of Cement Factory Waste Water on the Heavy Metal Contents of a Typical Low-Latitude Stream in North Central Nigeria

Abstract

Sediment and water samples from Oinyi River were collected bi-monthly from three sampling stations and analyzed for heavy metals in order to ascertain their distribution in sediment and water of the river, and also to determine the effects of the cement factory waste water on heavy metal concentration of the studied river. Station 1, located upstream of point of discharge of cement factory waste water, served as control point. Station 2 was immediately downstream of the factory’s waste water discharge point, and was designated as impact site while station 3 which was selected as the recovery site was downstream of both station 1 and 2. The cement factory waste water impacted negatively on the water chemistry and sediment of the river. Values obtained from river water sample showed that Zinc (0.05-0.054mg/l) and Copper (0.004-0.008mg/l) had their highest values at station 2 while the values of Manganese (114.8–115.8mg/kg), Zinc (6.07–6.26 mg/kg), Copper (3.3–3.39 mg/kg), Nickel (5.2–6 mg/kg), Lead (0.4–0.55 mg/kg), Chromium (0.3–0.45 mg/kg) and Cadmium (0.15–0.24 mg/kg), of river sediment, were also highest at the cement impacted site. However, there was reduction in the amount of Iron (92.4–93.8 mg/kg) in sediment sample of impacted site. These noticeable increases in the heavy metal contents of the waste water impacted site may be attributed to the cement factory effluent, and if not checked or stopped may become a matter of health issue because of the enormous human activities taking place in the site, as recorded in the study.

Keywords: cement factory; waste water; heavy metals; sediment; water quality; Oinyi River.