THE EFFECT OF ENVIRONMENTAL WASTE DISCHARGE ON THE HYDROCHEMISTRY OF AGBOYI CREEK, LAGOS STATE

Abstract

The natural aquatic systems are extensively contaminated with heavy metals released from domestic, industrial and other man-made activities and this may have devastating effects on the ecological balance of the recipient environment and a diversity of aquatic organisms. This study therefore, investigated the presence of heavy metals in relation to environmental waste discharge in Agboyi creek and other physico-chemical parameters in order to draw a good management plan for the water body. Water samples were collected from December 2005 to June 2007, within a depth of 30cm, at 9 points using sampling bottles (2L). Some parameters such as Temperature, Transparency, Total Dissolved Solid (TDS), Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Iron (Fe), Zinc (Zn), Cadmium (Cd), and Lead (Pb) were determined in triplicates as described by APHA (1998). The result revealed that temperature was fairly constant during the dry (28^oC ª¤¡Þ0.01) and wet (29^oCª¤¡Þ0.02) seasons, TDS range between 94.00 mgL^-1 ª¤¡Þ2.02 in dry season and 92.00ª¤¡Þ1.06 in wet season. Dissolved oxygen was 5.20ª¤¡Þ0.21 and 5.40ª¤¡Þ0.32 for dry and wet season respectively. Transparency was higher during the dry season (1.20m ª¤¡Þ 0.07) than the wet season (1.10ª¤¡Þ0.03). All water quality parameters analyzed vary insignificantly (P>0.05). The concentration of Fe (2.35ª¤¡Þ0.04 and 3.90ª¤¡Þ0.09) and Cd (0.06ª¤¡Þ0.01 and 0.09ª¤¡Þ0.02) were higher during the dry season than the wet season respectively. Zinc is negatively correlated with lead (r = -0.6532) and Cadium (r = -0.1361). The physico-chemical status of Agboyi creek can be attributed to unregulated human activities whose resultant effect on the aquatic organisms may be devastating if not controlled.