Abstract

The study assessed the seasonal variations in the physico-chemical properties of surface water and sediments in some villages located around a scrap metal recycling industry in Ile-Ife. This is with a view to monitor the impact of the industry on the quality of surrounding water. The three water bodies (one river, one stream and one pond) identified in the area were sampled every other month for ten months. Water and sediment were sampled from the water bodies and their physico-chemical properties were determined using standard methods. Highest and least pH values: 7.15 ± 0.29 and 6.27 ± 0.26 were recorded in river and pond water sample, respectively during dry season, while the least pH values: 5.64 ± 0.09 were recorded in sediment samples from the river during wet season. Fe in water was highest in pond during dry season with (0.10 ± 0.01) mg/L. Stream sediment recorded higher values of Fe (1.02 ± 0.05) mg/kg, Zn (0.48 ± 0.01) mg/kg and Pb (0.09 ± 0.01) mg/kg than in stream water samples, while the values of pH, Mn, Cd and Cr (6.95 ± 0.03, 0.67 ± 0.11, 0.11 ± 0.02, 0.17 ± 0.03)mg/L respectively in stream water were higher than in stream sediment samples. In River, Fe and Zn values were higher in sediment (0.63 ± 0.04 and 0.52 ± 0.01)mg/kg respectively than in water samples, while in the pond pH, Mn, Cd and Cr were higher in water (6.51 ± 0.12, 0.71 ± 0.07, 0.09 ± 0.01 and 0.22 ± 0.03)mg/L respectively than in sediment samples. The study concluded that the scrap metal recycling industry has impact on the surrounding water bodies as the values of cadmium, lead and iron significantly exceeded the national and international standards.

Key words: Physico-chemical, standards, sediment, scrap metal, seasonal, surface water.